Case Report Open Access
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 28, 2017; 23(12): 2258-2265
Published online Mar 28, 2017. doi: 10.3748/wjg.v23.i12.2258
Multiple clear-cell sarcomas of small intestine with parotid gland metastasis: A case report
Hao Su, Peng Wang, Lei Shi, Hai-Tao Zhou, Department of Colorectal Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
Wen-Sheng Liu, Department of Head and Neck Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
Wen-Hao Ren, Department of Pathology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
Author contributions: Su H collected the data and drafted the manuscript; Zhou HT designed the study and helped revise the manuscript; Liu WS collected the surgical specimens; Ren WH participated in the discussions of the postoperative pathology; Shi L conceived the study and participated in the coordination; Wang P participated in the data interpretation; all authors have read and approved the final manuscript.
Supported by Basic Scientific Research Business of Chinese Academy of Medical Sciences, No. 2016ZX310020.
Institutional review board statement: This case report was exempt from the Institutional Review Board review at Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College.
Informed consent statement: The patient involved in this study gave her written informed consent authorizing the use and disclosure of her protected health information.
Conflict-of-interest statement: All the authors have no conflict of interest to declare.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Hai-Tao Zhou, MD, Professor, Department of Colorectal Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17, Pan Jia Yuan Nan Li, Chaoyang District, Beijing 100021, China. zhouhaitao01745@163.com
Telephone: +86-10-67787110 Fax: +86-10-67787110
Received: December 6, 2016
Peer-review started: December 8, 2016
First decision: January 10, 2017
Revised: January 23, 2017
Accepted: February 16, 2017
Article in press: February 17, 2017
Published online: March 28, 2017
Processing time: 111 Days and 11.5 Hours

Abstract

Clear-cell sarcoma is a rare, malignant soft tissue tumor that displays melanocytic differentiation with a distinct molecular profile. It is rarely localized in the gastrointestinal tract. Herein we reported a case of multiple synchronous clear-cell sarcomas of the gastrointestinal tract with parotid gland metastasis. A 51-year-old male patient presented with a growing painless mass under the right ear. A preoperative positron emission tomography/computed tomography showed multiple intestinal masses and a mass in the right parotid with increased glucose uptake, and he underwent operative treatment with resection of three tumors in the jejunum and ileum and then received a right parotidectomy. Postoperative pathological examination showed that cells in the intestinal tumor were consistent with clear-cell sarcoma of the gastrointestinal tract, and the malignant cells in the parotid gland were similar to the intestinal tumor. Immunohistochemical studies revealed positive expression of HMB-45, Melan-A, and S-100. EWSR1 gene fusion transcripts were undetectable by fluorescence in situ hybridization.

Key Words: Clear-cell sarcomas, Clear-cell sarcomas of the gastrointestinal tract, Parotid gland metastasis, Immunohistochemistry

Core tip: Over the past 13 years, only 53 cases of clear-cell sarcomas of the gastrointestinal tract (CCS-GI) have been reported in the world. Most of the literature on CCS-GI describes a single tumor at diagnosis; our presentation is the third report of simultaneous tumors during the diagnosis to date and is the first case of CCS-GI with metastasis to the parotid gland. We also reviewed the literature on CCS-GI. Because of the high rarity, more cases need to be accumulated for further analysis.



INTRODUCTION

Clear-cell sarcoma (CCS) is a rare tumor of unknown origin that was first described by Enzinger[1] in 1965. CCS shows a predilection for the tendons or aponeuroses in the extremities in young adults aged 20-40 years[2]. Ekfors et al[3] described the first clear-cell sarcoma of the gastrointestinal tract (CCS-GI) in 1993, which occurred in the duodenum. Only a few cases[4] of CCS-GI have been reported. CCS-GI has specific histopathological, immunohistochemical, and genetic features. Here, we present a case of three synchronous clear-cell sarcomas in the jejunum and ileum with parotid gland metastasis.

CASE REPORT
Patient details

A 51-year-old male presented with a two-year history of a growing painless mass under the right ear, initially with a size of a soybean. The mass grew noticeably in the last six months. There was a one-year history of night sweat and frequent stool (three to four times a day). There was no history of fever, weakness, dysphagia, dyspnea, cough, hoarseness, jaundice, vomiting, melena, hematochezia, abdominal pain, abdominal distension or significant weight loss. The patient had a 5-year medical history of hypertension and he was a hepatitis-B carrier of 30 years and a smoker of 40 pack-years. There was no family history of cancer.

On palpation, a 20 mm × 20 mm relatively well-defined and soft mass with no tenderness was observed along with multiple enlarged cervical nodules. Abdominal examination did not reveal any organomegaly or palpable lumps.

Ultrasonography of the neck two months ago revealed a relatively undefined hypoechoic mass measuring approximately 15 mm × 27 mm in its greatest dimension in the right parotid gland and submandibular gland (Figure 1) along with multiple enlarged right supraclavicular and upper cervical lymph nodes. A needle biopsy of the mass was performed and the pathologic report found malignant tumor cells. The patient was recommended for surgery for the mass in the parotid gland. The preoperative blood routine examination showed that the HGB was 106 g/L. Therefore, the patient underwent positron emission tomography/computed tomography (PET/CT). A 36 mm × 33 mm intestinal mass with increased glucose uptake, and multiple peripheral lymph nodes in the right mid-abdomen were found (Figure 2), and the maximum standard uptake value (SUV) was 6.6. An intestinal lesion with increased glucose uptake in the right hypogastrium was also seen and the SUV was 7.0. The mass in the right parotid and peripheral lymph nodes also showed increased glucose uptake, and the SUV was 10.3. Preoperative tumor makers, such as CA125, CA15-3, CA19-9,CA72-4, AFP, cyfra21-1, NSE,SCC, CEA, and ProGRP, did not show abnormal expression.

Figure 1
Figure 1 Ultrasonogram of the neck showed a 15 mm × 27 mm mass in the right parotid gland.
Figure 2
Figure 2 positron emission tomography/computed tomography showed a 36 mm × 33 mm intestinal mass with multiple peripheral lymph nodes in the right midabdomen.
Treatment

The patient underwent an exploratory laparotomy and the excision of multiple intestinal neoplasms. Operative exploration showed no ascites, pelvic, periaortic, peritoneal, omental deposits, or liver metastasis. No tumors were palpated in the cavity of the stomach, duodenum, colon, rectum, or the mesentery root. Three masses were found at the jejunum and ileum. Intra-operatively, the first tumor was present in the jejunum, located at 80 cm distal to the duodenojejunal junction. Intussusception was observed at the point, and the involved bowels were swollen and expanded (Figure 3). The second tumor was at the end of the intussusception (approximately at the fourth loop of intestine). The third tumor was present in the ileum, located at 80 cm proximal to the ileocecal junction. These three tumors of varying sizes invaded the serosa, and the surface of the serosa had shrunk and was depressed. Multiple enlarged lymph nodes were observed in the intestinal mesentery. Following serial ligation of the mesenteric vessels, resection of the involved bowels, along with the masses and mesentery, was performed, with a proximal margin of 10 cm and a distal margin of 10 cm. The first and second tumors were removed together in one segment of the intestine (Figure 4). Then, a primary anastomosis formed. The patient recovered gradually and then underwent right parotidectomy with retention of the facial nerve, followed by right cervical lymph node dissection 17 d after abdominal surgery because the pathology of the parotid gland neoplasms was undetermined.

Figure 3
Figure 3 Intussusception was observed 80 cm distal to the duodenojejunal junction and the involved bowels were swollen and expanded.
Figure 4
Figure 4 Involved bowels with the masses and mesentery were resected with a proximal 10 cm and distal 10 cm margin.
Postoperative pathology

Intestinal neoplasms: Upon gross examination, the specimen consisted of two segments of the small intestine: the longer one was approximately 26 cm with attached mesentery, and the other segment was 7.8 cm with attached mesentery. Two tumors were on the longer segment of intestine, one (2.5 cm × 2.2 cm × 1 cm) was at 11 cm from one margin and the other (6.5cm × 5.5cm × 4 cm) was at 19 cm from the same margin. A 2.5 cm × 1.9 cm × 1 cm tumor was on the other segment of the small intestine. The cut surface of the three tumors had hard, obscure borders that were white to tan in appearance.

Microscopically, the jejunum and ileum tissues were infiltrated with malignant cells, which was consistent with CCS-GI (a type of gastrointestinal neural ectoderm tumor, GNET) based on morphology and immunohistochemistry (Figure 5A). The tumors had invaded the mucosal and muscular layers. There was no focal necrosis, vessel invasion or nerve invasion. The mitotic index exceeded 20/10 HPFs, and the tumor was grade G3 according to the FNCLL (French Fédération Nationale des Centres de Lutte Contre le Cancer) system.

Figure 5
Figure 5 Microscopic observation of intestinal neoplasms and parotid gland neoplasms. A: Microphotography shows that polygonal malignant cells of intestinal neoplasms were separated by fibrous tissues, arranging in sheets and nests, with eosinophilic or clear cytoplasm and there was no exact necrosis, vessel invasion and nerve invasion. Nucleolus was obvious and the mitotic index exceeded 20/10 HPF (Hematoxylin-Eosin G × 10); B: Malignant cells of parotid gland neoplasms were similar to the intestinal tumor by microphotography (Hematoxylin-Eosin G × 10).

Lymph node metastases (1/29) without invasion of the outer lymph node capsule: (1) peripheral lymph nodes of the jejunum: 1/26; and (2) peripheral lymph nodes of the ileum, 0/3.

Immunohistochemistry: S100 (3+), Vim (3+), GFAP (-), HMB-45 (2+), Melan-A (2+), Melanomapan (1+), CD56 (2+), Syn (-), CgA (-), AE1/AE3 (-), CD138 (-), CD19 (-), CD20 (-), CD3 (-), CD38 (-), CD79a (-), Ki-67 (+40%), LCA (-), MUM1 (-), CD117 (lesion+), CD34 (-), DOG1 (-), CD10 (-), Calponin (-), P63 (-), EBER (-).

Gene detection: EWSR1 gene fusion transcripts were undetectable by fluorescence in situ hybridization (FISH).

Parotid gland neoplasms: Upon gross examination, a 1-cm diameter nodule was found in a 5.5 cm × 3 cm × 2 cm area of tissue; the cut surface of the nodule had a tough, grey-to-yellow appearance.

Microscopically, the parotid gland tissues were infiltrated with malignant cells, which was consistent with CCS morphology and immunohistochemistry and morphologically similar to the previously assessed intestinal tumor (Figure 5B). Lymph tissues were found in the tumor and at the tumor edge, which may be metastatic lesions.

No lymph node metastases (0/30): (1) right cervical lymph nodes, level II, 0/10; (2) right cervical lymph nodes, level III, 0/12; (3) right cervical lymph nodes, level V, 0/5; (4) peripheral lymph nodes of the superficial lobe of the right parotid gland, 0/2; and (5) peripheral lymph nodes of the caudate lobe of the right parotid gland and tumor, 0/1.

Immunohistochemistry: S100 (3+), Melan-A (3+), Melanomapan (3+), HMB-45 (3+), AE1/AE3 (-), CK18 (-), Calponin (-), P63 (-), SMA (-).

Follow-up

Twenty days after the surgery on the parotid gland, the patient underwent CT imaging of the neck, thorax and abdominopelvic area, and no recurrence or metastasis was observed. He then started with 6 cycles of chemotherapy using an EI regimen (epirubicin 100 mg + ifosfamide 2 g D1-4+mesna 0.4 g 0 h, 4 h, and 8 h after the ifosfamide D1-4). At the time that this article was written, the patient was on the first cycle of the chemotherapy.

DISCUSSION

CCS-GI is so rare that only 53 cases (including our case) have been reported in the literature to date (Table 1)[3,5-39]. Most of the literature on CCS-GI describes the diagnosis of a single tumor; only two case reports[25,38] have described the diagnosis of two simultaneous tumors to date. CCS-GI often involves the ileum and jejunum, stomach and colon[4-7,9-12,14-35,38,39]. Because of the aggressive clinical course, regional and distant metastases are common in CCS-GI at presentation[5-7,9,10,15,17,21,25,27,29,31,37,39]. The lymph nodes, liver, and mesentery are the most common locations of the metastases at the time of presentation. The patient in our report had three synchronous masses in the jejunum and ileum, with metastasis to the parotid gland, and he attended the hospital mainly due to the swollen parotid gland. The presence of lymph nodes both inside and outside of the parotid gland makes it a common site of metastasis for head and neck neoplasms[40], but it is a very rare metastatic site for gastrointestinal tumors. In the limited literature on CCS-GI, this is the first case of CCS-GI with metastasis to the parotid gland.

Table 1 Clinical, pathological, immunohistochemical and genetic features of clear-cell sarcoma of the gastrointestinal tract in previously reported cases.
Ref.Age (yr)/sexLocationMaximum diameter of tumor(cm)S-100HMB-45Melan-AGenetic findingsOutcome
Alpers et al[5]26/FJejunum1.5NDNDNDNDLiver mets
Ekfors et al[3]38/MDuodenum3.0PositivePositiveNDNDNot given
Donner et al[6]37/MIleum6.5PositiveNegativeNDt(12;22)(q13;q12-13)Liver mets at 24 and 36 mo
Fukuda et al[7]74/MColon3.0PositivePositiveNDEWSR1-ATF1 by RT-PCRLiver mets at 9 mo
Hu et al[8]10/MRectum5.0PositivePositiveNDNDNA
Pauwels et al[9]30/MStomach4.0PositiveNegativeNDt(12;22)(q13;q12)LN and peritoneal mets at diagnosis
Zambrano et al[10]15/FJejunum5.0PositiveNegativeNegativet(12;22)(q13;q12)DOD 16 mo
21/FJejunum4.0PositiveNegativeNegativeNDDOD 12 mo
35/FIleum3.5PositiveNegativeNegativeNDLiver mets at 12 mo
37/FIleum4.5PositiveNegativeNegativeNDNA
32/MIleum5.0PositiveNegativeNegativeNDNA
13/MStomach6.7PositiveNegativeNegativeNDLocal recurrence at 12 mo;2nd Local recurrence at 36 mo
Achten et al[11]57/MJejunum6.5PositiveNegativeNegativeEWSR1 rearrangement by FISHNA
Venkataraman et al[12]21/FIleum7.0PositiveNegativeNegativeEWSR1 rearrangement by FISHNA
Covinsky et al[13]47/FPancreasNAPositivePositivePositiveEWSR1-ATF1NED 24 mo
by RT-PCR and
FISH
85/FMesenteryNAPositivePositivePositiveEWSR1-ATF1DOD 1 mo
by RT-PCR and
FISH
Taminelli et al[14]35/MIleum1.8PositiveNegativePositiveEWSR1-ATF1/ by RT-PCRDOD 15 mo
Friedrichs et al[15]41/MJejunum8.7PositiveNegativeNegativeEWSR1 rearrangement by FISHLiver mets at 6 mo
Huang et al[16]40/MStomach3.0PositiveNegativePositiveNDNED 9 mo
Antonescu et al[17]81/FColon7.5PositiveNegativeNegativeEWSR1-CREB1 by RT-PCRMets to liver and
peritoneum at
60 mo
42/FIleum5.7PositiveNegativeNegativeEWSR1-CREB1 by RT-PCRNA
42/FIleum3.5PositiveNegativeNegativeEWSR1-CREB1 by RT-PCRPeritoneal and
liver mets at
diagnosis
51/FJejunumNAPositiveNegativeNegativeEWSR1Peritoneal and
rearrangementliver mets; AWD
by FISH
18/FJejunumNAPositiveNegativeNegativeEWSR1-ATF1 by RT-PCRLocal recurrence
Granville et al[18]16/MIleum5.0PositiveNegativeNDEWSR1-ATF1 by RT-PCR; t(12;22)(q13;q12)DOD 15 mo
Comin et al[19]31/FIleum2.8PositiveNegativeNegativeEWSR1 rearrangement by FISHNA
Lyle et al[20]46/MJejunum11.0PositivePositivePositiveEWSR1 rearrangement by FISH; EWSR1-ATF1 by RT-PCRNED 7 mo
49/MCecum10.5PositivePositivePositiveEWSR1 rearrangement by FISH; EWSR1-ATF1 by RT-PCRDOD 12 mo
60/MJejunum10.0PositivePositivePositiveEWSR1-ATF1 by RT-PCRDOD 28 mo
62/MIleum4.0PositivePositivePositiveEWSR1 rearrangement by FISH; EWSR1-ATF1 by RT-PCRDOD 12 mo
Abdulkader et al[21]37/MJejunum8.2PositiveNegativeNDEWSR1 rearrangement by FISHLiver mets at 2 mo
Lagmay et al[22]10/FStomach7.8PositiveNegativeNegativeEWSR1 rearrangement by FISH; EWSR1-ATF1 by RT-PCRNED 4 mo
Joo et al[23]60/MIleum2.4PositiveNegativeNegativeEWSR1 rearrangement by FISHNA
46/MJejunum6.0PositiveNegativeNegativeEWSR1 rearrangement by FISHNA
Terazawa et al[24]Early 20s/FIleum3.0PositiveNDNDEWSR1-ATF1 by RT-PCRNED at 24 mo
Shenjere et al[25]53/FIleum5.0PositiveNegativeNegativeEWSR1-ATF1 by RT-PCRRegional LN mets at diagnosis/ NED at 7 mo
26/FSmall and large bowel113.5/10.1PositiveNegativeNegativeEWSR1-CREB1 by RT-PCRNA
66/MIleum2.5PositiveNegativeNegativeEWSR1-CREB1 by RT-PCRRegional LN mets at diagnosis/NED
Balkaransingh et al[26]15/MIleumNANDNDNDEWSR1 rearrangement by FISHNA
Yang et al[27]15/MIleum4.0PositiveNDNDEWSR1 rearrangement by FISHLiver mets at 12 mo
Suárez-Vilela et al[28]36/FJejunum1.5PositiveNegativeNegativeEWSR1 rearrangement by FISHNA
D’Amico et al[29]69/FIleum4.0PositiveNegativeNDEWSR1 rearrangement by FISHLiver mets at 2 mo
Lasithiotakis et al[30]49/FJejunum3.0PositiveNegativeNegativeEWSR1 rearrangement by FISHNED 20 mo
Huang et al[31]45/FColon4.0PositiveNegativeNegativeEWSR1 rearrangement by FISHLiver mets at 20 mo
Mallick et al[32]45/MJejunum4.4PositiveNegativeNegativeNDNA
Kong et al[33]17/MStomach6.0PositiveNegativeNegativeEWSR1 rearrangement by FISHNED 10 mo
Liu et al[34]76/MJejunum2.5PositiveNegativeNegativeEWSR1-ATF1 by RT-PCRNA
Thway et al[35]36/MIleum3.0PositiveNegativeNegativeEWSR1-CREB1 by RT-PCRDOD 7 mo
Huang [36]36/MPancreas4.0PositivePositivePositiveEWSR1 rearrangement by FISHLiver mets at 10 mo
Yegen et al[37]25/FIleum3.2PositiveNegativeNegativeEWSR1 rearrangement by FISHLiver mets at diagnosis and at 15 mo. Ovarian mets and peritoneal dissemination at 47 mo
Moslim et al[38]57/MDuodenum and Jejunum25.5/7.5PositiveNegativePositiveEWSR1 rearrangement by FISHNED 30 mo and then DOD 4 mo later
Chen et al[39]29/FJejunum6.0PositiveNegativeNegativeEWSR1 rearrangement by FISHNED 17 mo
Our case51/MDuodenum and Jejunum36.5/2.5/2.5PositivePositivePositiveEWSR1 rearrangement undetectable by FISHNED up to date

CCS-GI shows specific histopathological, immunohistochemical, ultrastructural, and genetic features[2,4]. In 2010, Kosemehmetoglu et al[41] first divided CCS-GI into two subtypes according to its histomorphology: (1) CCS-like gastrointestinal tumor (CCSLGT); and (2) CCS of soft tissue (CCS-ST). However, there has been disagreement about whether these subtypes are two independent entities[31]. In 2003, Zambrano et al[10] reported 6 cases of CCSLGTs. They found that the CCSLGTs were at least focally positive for the S100 protein, but most did not express melanocytic markers such as HMB-45 or Melan-A. Meanwhile, Huang et al[36] found that certain CCS-STs were positive for the S100 protein and most could express melanocytic markers such as HMB-45 or Melan-A. Several reports found that > 90% of cases of CCS were associated with the reciprocal translocation t (12; 22) (q13; q12), resulting in fusion of the EWSR1 gene, located at 22q12, and the ATF1 gene, located at 12q13[2,41-46]. To date, these translocations have never been observed in malignant melanoma[13,22,43-46], which has a very similar histologic appearance to CCS[20]. Immunohistochemical staining of CCS reveals positivity for the S100 protein as well as melanocyte-specific markers, with this combination of staining allowing for CCS to be distinguished from malignant melanoma histologically. In our case, the tumor was consistent with CCS-GI based on morphology, was positive for the S100 protein, and expressed melanocytic markers such as HMB-45 and Melan-A, but EWSR1 gene fusion transcripts were undetectable by FISH.

Currently the most effective treatment for CCS-GI is extensive resection of the tumor and peripheral lymph nodes; chemotherapy and radiotherapy appear to have little effect[31]. The clinical behavior of CCS-GI seems to be highly aggressive, with high rates of local recurrence, lymph node or visceral metastases, and death, generally within < 36 mo[41,46]. In the current report, the patient underwent excision of multiple intestinal neoplasms and right parotidectomy before the first cycle of the chemotherapy and no recurrence or metastasis has been observed during the follow-up to date.

In conclusion, CCS-GI is a highly rare soft-tissue sarcoma with distinct morphological, immunohistochemical, and genetic features. This case demonstrates that the parotid gland is a potential metastatic site for CCS-GI. Prior to developing a routine method to diagnose and treat CCS-GI, more cases need to be accumulated for further analysis.

COMMENTS
Case characteristics

A 51-year-old male presented with a two-year history of a growing painless mass lesion under the right ear that had grown noticeably over the past six months and a one-year history of night sweat and frequent stool.

Clinical diagnosis

A relatively well-defined soft mass with no tenderness was observed along with multiple enlarged cervical nodules.

Differential diagnosis

Small intestinal stromal tumors, lymphoma, head and neck neoplasm, sarcomatoid carcinoma.

Laboratory diagnosis

The patient’s laboratory test had no remarkable findings.

Imaging diagnosis

Positron emission tomography/computed tomography showed an intestinal mass with involvement of multiple peripheral lymph nodes and mass in the right parotid.

Pathological diagnosis

The intestinal neoplasms and parotid gland neoplasm were consistent with CCS based on morphology and immunohistochemistry.

Treatment

The patient underwent curative resection and postoperative chemotherapy.

Related reports

Only 53 cases of clear-cell sarcomas of the gastrointestinal tract (CCS-GI) have been reported in the literature to date, and CCS-GI shows distinct morphological, immunohistochemical, and genetic features.

Term explanation

CCS-GI is a highly rare soft tissue sarcoma.

Experiences and lessons

The present case report is the third instance of diagnosis of simultaneous multiple CCS-GIs to date and the first case of CCS-GI with metastasis to the parotid gland.

Peer-review

The authors have described a case of multiple clear-cell sarcomas of the small intestine with parotid gland metastasis. The article highlights the morphological, immunohistochemical, and genetic features of the tumors.

Footnotes

Manuscript source: Unsolicited manuscript

Specialty type: Gastroenterology and hepatology

Country of origin: China

Peer-review report classification

Grade A (Excellent): 0

Grade B (Very good): B

Grade C (Good): 0

Grade D (Fair): D

Grade E (Poor): 0

P- Reviewer: Muhammad JS, Mulder KE S- Editor: Ma YJ L- Editor: Ma JY E- Editor: Wang CH

References
1.  Enzinger FM. Clear-cell sarcoma of tendons and aponeuroses. An analysis of 21 cases. Cancer. 1965;18:1163-1174.  [PubMed]  [DOI]  [Cited in This Article: ]
2.  Hocar O, Le Cesne A, Berissi S, Terrier P, Bonvalot S, Vanel D, Auperin A, Le Pechoux C, Bui B, Coindre JM. Clear cell sarcoma (malignant melanoma) of soft parts: a clinicopathologic study of 52 cases. Dermatol Res Pract. 2012;2012:984096.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 70]  [Cited by in F6Publishing: 73]  [Article Influence: 6.1]  [Reference Citation Analysis (0)]
3.  Ekfors TO, Kujari H, Isomäki M. Clear cell sarcoma of tendons and aponeuroses (malignant melanoma of soft parts) in the duodenum: the first visceral case. Histopathology. 1993;22:255-259.  [PubMed]  [DOI]  [Cited in This Article: ]
4.  Stockman DL, Miettinen M, Suster S, Spagnolo D, Dominguez-Malagon H, Hornick JL, Adsay V, Chou PM, Amanuel B, Vantuinen P. Malignant gastrointestinal neuroectodermal tumor: clinicopathologic, immunohistochemical, ultrastructural, and molecular analysis of 16 cases with a reappraisal of clear cell sarcoma-like tumors of the gastrointestinal tract. Am J Surg Pathol. 2012;36:857-868.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 137]  [Cited by in F6Publishing: 127]  [Article Influence: 10.6]  [Reference Citation Analysis (0)]
5.  Alpers CE, Beckstead JH. Malignant neuroendocrine tumor of the jejunum with osteoclast-like giant cells. Enzyme histochemistry distinguishes tumor cells from giant cells. Am J Surg Pathol. 1985;9:57-64.  [PubMed]  [DOI]  [Cited in This Article: ]
6.  Donner LR, Trompler RA, Dobin S. Clear cell sarcoma of the ileum: the crucial role of cytogenetics for the diagnosis. Am J Surg Pathol. 1998;22:121-124.  [PubMed]  [DOI]  [Cited in This Article: ]
7.  Fukuda T, Kakihara T, Baba K, Yamaki T, Yamaguchi T, Suzuki T. Clear cell sarcoma arising in the transverse colon. Pathol Int. 2000;50:412-416.  [PubMed]  [DOI]  [Cited in This Article: ]
8.  Hu XL, Wang WX. Clear cell sarcoma of the rectum: a case report. Zhonghua Bing Li Xue Za Zhi. 2001;30:77.  [PubMed]  [DOI]  [Cited in This Article: ]
9.  Pauwels P, Debiec-Rychter M, Sciot R, Vlasveld T, den Butter B, Hagemeijer A, Hogendoorn PC. Clear cell sarcoma of the stomach. Histopathology. 2002;41:526-530.  [PubMed]  [DOI]  [Cited in This Article: ]
10.  Zambrano E, Reyes-Mugica M, Franchi A, Rosai J. An osteoclast-rich tumor of the gastrointestinal tract with features resembling clear cell sarcoma of soft parts: reports of 6 cases of a GIST simulator. Int J Surg Pathol. 2003;11:75-81.  [PubMed]  [DOI]  [Cited in This Article: ]
11.  Achten R, Debiec-Rychter M, De Wever I, Sciot R. An unusual case of clear cell sarcoma arising in the jejunum highlights the diagnostic value of molecular genetic techniques in establishing a correct diagnosis. Histopathology. 2005;46:472-474.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 20]  [Cited by in F6Publishing: 20]  [Article Influence: 1.1]  [Reference Citation Analysis (0)]
12.  Venkataraman G, Quinn AM, Williams J, Hammadeh R. Clear cell sarcoma of the small bowel: a potential pitfall. Case report. APMIS. 2005;113:716-719.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 35]  [Cited by in F6Publishing: 36]  [Article Influence: 2.0]  [Reference Citation Analysis (0)]
13.  Covinsky M, Gong S, Rajaram V, Perry A, Pfeifer J. EWS-ATF1 fusion transcripts in gastrointestinal tumors previously diagnosed as malignant melanoma. Hum Pathol. 2005;36:74-81.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 68]  [Cited by in F6Publishing: 69]  [Article Influence: 3.6]  [Reference Citation Analysis (0)]
14.  Taminelli L, Zaman K, Gengler C, Peloponissios N, Bouzourene H, Coindre JM, Hostein I, Guillou L. Primary clear cell sarcoma of the ileum: an uncommon and misleading site. Virchows Arch. 2005;447:772-777.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 48]  [Cited by in F6Publishing: 48]  [Article Influence: 2.5]  [Reference Citation Analysis (0)]
15.  Friedrichs N, Testi MA, Moiraghi L, Modena P, Paggen E, Plötner A, Wiechmann V, Mantovani-Löffler L, Merkelbach-Bruse S, Buettner R. Clear cell sarcoma-like tumor with osteoclast-like giant cells in the small bowel: further evidence for a new tumor entity. Int J Surg Pathol. 2005;13:313-318.  [PubMed]  [DOI]  [Cited in This Article: ]
16.  Huang W, Zhang X, Li D, Chen J, Meng K, Wang Y, Lu Z, Zhou X. Osteoclast-rich tumor of the gastrointestinal tract with features resembling those of clear cell sarcoma of soft parts. Virchows Arch. 2006;448:200-203.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 40]  [Cited by in F6Publishing: 34]  [Article Influence: 1.8]  [Reference Citation Analysis (0)]
17.  Antonescu CR, Nafa K, Segal NH, Dal Cin P, Ladanyi M. EWS-CREB1: a recurrent variant fusion in clear cell sarcoma--association with gastrointestinal location and absence of melanocytic differentiation. Clin Cancer Res. 2006;12:5356-5362.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 257]  [Cited by in F6Publishing: 262]  [Article Influence: 14.6]  [Reference Citation Analysis (0)]
18.  Granville L, Hicks J, Popek E, Dishop M, Tatevian N, Lopez-Terrada D. Visceral clear cell sarcoma of soft tissue with confirmation by EWS-ATF1 fusion detection. Ultrastruct Pathol. 2006;30:111-118.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 34]  [Cited by in F6Publishing: 25]  [Article Influence: 1.4]  [Reference Citation Analysis (0)]
19.  Comin CE, Novelli L, Tornaboni D, Messerini L. Clear cell sarcoma of the ileum: report of a case and review of literature. Virchows Arch. 2007;451:839-845.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 39]  [Cited by in F6Publishing: 39]  [Article Influence: 2.3]  [Reference Citation Analysis (0)]
20.  Lyle PL, Amato CM, Fitzpatrick JE, Robinson WA. Gastrointestinal melanoma or clear cell sarcoma? Molecular evaluation of 7 cases previously diagnosed as malignant melanoma. Am J Surg Pathol. 2008;32:858-866.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 62]  [Cited by in F6Publishing: 49]  [Article Influence: 3.1]  [Reference Citation Analysis (0)]
21.  Abdulkader I, Cameselle-Teijeiro J, de Alava E, Ruiz-Ponte C, Used-Aznar MM, Forteza J. Intestinal clear cell sarcoma with melanocytic differentiation and EWS [corrected] rearrangement: report of a case. Int J Surg Pathol. 2008;16:189-193.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 16]  [Cited by in F6Publishing: 16]  [Article Influence: 1.0]  [Reference Citation Analysis (0)]
22.  Lagmay JP, Ranalli M, Arcila M, Baker P. Clear cell sarcoma of the stomach. Pediatr Blood Cancer. 2009;53:214-216.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 31]  [Cited by in F6Publishing: 31]  [Article Influence: 2.1]  [Reference Citation Analysis (0)]
23.  Joo M, Chang SH, Kim H, Gardner JM, Ro JY. Primary gastrointestinal clear cell sarcoma: report of 2 cases, one case associated with IgG4-related sclerosing disease, and review of literature. Ann Diagn Pathol. 2009;13:30-35.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 32]  [Cited by in F6Publishing: 28]  [Article Influence: 1.8]  [Reference Citation Analysis (0)]
24.  Terazawa K, Otsuka H, Morita N, Yamashita K, Nishitani H. Clear-cell sarcoma of the small intestine detected by FDG-PET/CT during comprehensive examination of an inflammatory reaction. J Med Invest. 2009;56:70-75.  [PubMed]  [DOI]  [Cited in This Article: ]
25.  Shenjere P, Salman WD, Singh M, Mangham DC, Williams A, Eyden BP, Howard N, Knight B, Banerjee SS. Intra-abdominal clear-cell sarcoma: a report of 3 cases, including 1 case with unusual morphological features, and review of the literature. Int J Surg Pathol. 2012;20:378-385.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 22]  [Cited by in F6Publishing: 23]  [Article Influence: 1.8]  [Reference Citation Analysis (0)]
26.  Balkaransingh P, Saad SA, Govil SC, Thind PK, Ballance CM, Weiss AR. Clear cell sarcoma of the gastrointestinal tract presenting as a second malignant neoplasm following neuroblastoma in infancy. Pediatr Blood Cancer. 2012;58:481-482.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 17]  [Cited by in F6Publishing: 19]  [Article Influence: 1.6]  [Reference Citation Analysis (0)]
27.  Yang JC, Chou AJ, Oeffinger KC, La Quaglia MP, Wolden SL. Clear cell sarcoma of the gastrointestinal tract after very low-dose therapeutic radiation therapy: a case report. J Pediatr Surg. 2012;47:1943-1945.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 18]  [Cited by in F6Publishing: 19]  [Article Influence: 1.6]  [Reference Citation Analysis (0)]
28.  Suárez-Vilela D, Izquierdo FM, Tojo-Ramallo S, R Riera-Velasco J, Escobar-Stein J. Malignant gastrointestinal neuroectodermal tumor showing overlapped immunophenotype with synovial sarcoma: CD99 and SOX10 antibodies are useful in differential diagnosis. Am J Surg Pathol. 2012;36:1905-198; author reply 1908.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 7]  [Cited by in F6Publishing: 8]  [Article Influence: 0.7]  [Reference Citation Analysis (0)]
29.  D’Amico FE, Ruffolo C, Romeo S, Massani M, Dei Tos AP, Bassi N. Clear cell sarcoma of the ileum: report of a case and review of the literature. Int J Surg Pathol. 2012;20:401-406.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 19]  [Cited by in F6Publishing: 21]  [Article Influence: 1.6]  [Reference Citation Analysis (0)]
30.  Lasithiotakis K, Protonotarios A, Lazarou V, Tzardi M, Chalkiadakis G. Clear cell sarcoma of the jejunum: a case report. World J Surg Oncol. 2013;11:17.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 11]  [Cited by in F6Publishing: 12]  [Article Influence: 1.1]  [Reference Citation Analysis (0)]
31.  Huang HF, Liu Q, Hong BU, Chen M, Chen HJ, Lin YY, Zhang HY, Pathology DO, Hospital WC and University S. Clear cell sarcoma of gastrointestinal tract: clinicopathologic analyses and review of literatures. Linchuang Yu Shiyan Binglixue Zazhi. 2014;30:383-388.  [PubMed]  [DOI]  [Cited in This Article: ]
32.  Mallick S, Singh L, Rajan K, Sharma MC, Bansl V, Dinda AK. Malignant melanoma of soft parts with osteoclast-rich giant cells: A rare tumour of the jejunum. Australas Med J. 2014;7:181-184.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 1]  [Cited by in F6Publishing: 1]  [Article Influence: 0.1]  [Reference Citation Analysis (0)]
33.  Kong J, Nan LI, Shiwu WU, Guo X, Congyou GU and Feng Z. Malignant gastrointestinal neuroectodermal tumor: A case report and review of the literature. Oncol Lett. 2014;8:2687-2690.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 17]  [Cited by in F6Publishing: 19]  [Article Influence: 1.9]  [Reference Citation Analysis (0)]
34.  Liu C, Ren Y, Li X, Cao Y, Chen Y, Cui X, Li L, Li F. Absence of 19 known hotspot oncogenic mutations in soft tissue clear cell sarcoma: two cases report with review of the literature. Int J Clin Exp Pathol. 2014;7:5242-5249.  [PubMed]  [DOI]  [Cited in This Article: ]
35.  Thway K, Judson I, Fisher C. Clear cell sarcoma-like tumor of the gastrointestinal tract, presenting as a second malignancy after childhood hepatoblastoma. Case Rep Med. 2014;2014:984369.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 20]  [Cited by in F6Publishing: 22]  [Article Influence: 2.2]  [Reference Citation Analysis (0)]
36.  Huang J, Luo RK, Du M, Zeng HY, Chen LL, Ji Y. Clear cell sarcoma of the pancreas: a case report and review of literature. Int J Clin Exp Pathol. 2015;8:2171-2175.  [PubMed]  [DOI]  [Cited in This Article: ]
37.  Yegen G, Güllüoğlu M, Mete Ö, Önder S, Kapran Y. Clear cell sarcoma-like tumor of the gastrointestinal tract: a case report and review of the literature. Int J Surg Pathol. 2015;23:61-67.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 16]  [Cited by in F6Publishing: 16]  [Article Influence: 1.6]  [Reference Citation Analysis (0)]
38.  Moslim MA, Falk GA, Cruise M, Morris-Stiff G. Simultaneous Clear Cell Sarcomas of the Duodenum and Jejunum. Case Rep Med. 2016;2016:1534029.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 4]  [Cited by in F6Publishing: 4]  [Article Influence: 0.5]  [Reference Citation Analysis (0)]
39.  Chen L, Zhou AP. Small intestinal clear cell sarcoma in gestation period masquerading as an abdominal abscess. Clin Misdiagnosis and Mistherapy. 2016;29:33-34.  [PubMed]  [DOI]  [Cited in This Article: ]
40.  Park SW, Eade T, Pang L, Wignall A, Veivers D. Role of neck dissection in metastatic squamous cell carcinoma to the parotid gland. J Laryngol Otol. 2016;130 Suppl 4:S54-S59.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 5]  [Cited by in F6Publishing: 6]  [Article Influence: 0.9]  [Reference Citation Analysis (0)]
41.  Kosemehmetoglu K, Folpe AL. Clear cell sarcoma of tendons and aponeuroses, and osteoclast-rich tumour of the gastrointestinal tract with features resembling clear cell sarcoma of soft parts: a review and update. J Clin Pathol. 2010;63:416-423.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 77]  [Cited by in F6Publishing: 67]  [Article Influence: 4.8]  [Reference Citation Analysis (0)]
42.  Coindre JM. New WHO classification of tumours of soft tissue and bone. Ann Pathol. 2012;32:S115-S116.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 31]  [Cited by in F6Publishing: 30]  [Article Influence: 2.5]  [Reference Citation Analysis (0)]
43.  Wang WL, Mayordomo E, Zhang W, Hernandez VS, Tuvin D, Garcia L, Lev DC, Lazar AJ, López-Terrada D. Detection and characterization of EWSR1/ATF1 and EWSR1/CREB1 chimeric transcripts in clear cell sarcoma (melanoma of soft parts). Mod Pathol. 2009;22:1201-1209.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 159]  [Cited by in F6Publishing: 144]  [Article Influence: 9.6]  [Reference Citation Analysis (0)]
44.  Panagopoulos I, Mertens F, Isaksson M, Mandahl N. Absence of mutations of the BRAF gene in malignant melanoma of soft parts (clear cell sarcoma of tendons and aponeuroses). Cancer Genet Cytogenet. 2005;156:74-76.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 60]  [Cited by in F6Publishing: 61]  [Article Influence: 3.2]  [Reference Citation Analysis (0)]
45.  Panagopoulos I, Mertens F, Dêbiec-Rychter M, Isaksson M, Limon J, Kardas I, Domanski HA, Sciot R, Perek D, Crnalic S. Molecular genetic characterization of the EWS/ATF1 fusion gene in clear cell sarcoma of tendons and aponeuroses. Int J Cancer. 2002;99:560-567.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 118]  [Cited by in F6Publishing: 121]  [Article Influence: 5.5]  [Reference Citation Analysis (0)]
46.  Langezaal SM, Graadt van Roggen JF, Cleton-Jansen AM, Baelde JJ, Hogendoorn PC. Malignant melanoma is genetically distinct from clear cell sarcoma of tendons and aponeurosis (malignant melanoma of soft parts). Br J Cancer. 2001;84:535-538.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 113]  [Cited by in F6Publishing: 101]  [Article Influence: 4.4]  [Reference Citation Analysis (0)]