Case Report
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jul 26, 2021; 9(21): 6017-6025
Published online Jul 26, 2021. doi: 10.12998/wjcc.v9.i21.6017
Myeloid sarcoma of the colon as initial presentation in acute promyelocytic leukemia: A case report and review of the literature
Lei Wang, Da-Li Cai, Na Lin
Lei Wang, Da-Li Cai, Na Lin, Department of Hematology, The First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
Author contributions: Wang L and Cai DL guided the diagnosis and treatment of this case; Wang L and Lin N reviewed all the related literature and analyzed the clinical data; Wang L drafted the manuscript; Lin N critically revised the manuscript; all authors read and approved the final manuscript.
Supported by the National Natural Science Foundation of China (General Program), No. 81170519.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: The authors declare that they have no conflict of interest to report.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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:
Corresponding author: Na Lin, MD, Associate Professor, Department of Hematology, The First Affiliated Hospital of China Medical University, No. 155 Nanjing North Street, Shenyang 110001, Liaoning Province, China.
Received: January 31, 2021
Peer-review started: January 31, 2021
First decision: May 1, 2021
Revised: May 7, 2021
Accepted: May 26, 2021
Article in press: May 26, 2021
Published online: July 26, 2021

Myeloid sarcoma (MS) rarely occurs in acute promyelocytic leukemia (APL) at onset, but it can develop in relapse cases, especially after APL treated with all-trans retinoic acid (ATRA). Therefore little is known about the clinical features and suitable treatment for APL related MS due to the rarity of the disease, although this may be different from the treatment and prognosis of MS in the relapse stage. To our best knowledge, this is the second case report of APL initial presentation as colon MS.


A 77-year-old woman complained of intermittent right lower abdominal pain, black stool, and difficult defecation for 2 mo. Physical examination showed diffuse tenderness during deep palpation and an anemic appearance. Laboratory findings showed positivity for fecal occult blood testing; white blood cell count: 3.84 × 109/L; hemoglobin: 105 g/L; platelet count: 174 × 109/L; and negativity for tumor markers. Abdominal enhanced computed tomography showed a space occupying lesion in the colon (1.9 cm). Fibrocolonoscopy revealed a polypoid and ulcerated mass measuring 2.5 cm. The tumor was removed. To our surprise, MS was confirmed by immunohistochemistry. PML/RARα fusion gene was detected in colon specimens by fluorescent in situ hybridization and real-time reverse transcription polymerase chain reaction, which was consistent with the bone marrow. She was diagnosed as having APL related MS. A smooth and unobstructed intestinal wall was found by fibrocolonoscopy, and continuous molecular remission was confirmed in both the bone marrow and colon after four courses of ATRA + arsenic trioxide (ATO). ATRA + ATO showed a favorable therapeutic response for both APL and MS.


Early use of ATRA can benefit APL patients, regardless of whether MS is the first or recurrent manifestation.

Keywords: Acute promyelocytic leukemia, Myeloid sarcoma, All-trans retinoic acid, Extramedullary disease, Colon, Fluorescent in situ hybridization, Case report

Core Tip: Myeloid sarcoma (MS) rarely occurs in acute promyelocytic leukemia (APL) at onset. We report the second case of APL with colon MS as the initial presentation. De novo APL related MS is a very rare disease. Its clinical features and prognosis may be different from those of extramedullary disease, and the disease free survival may be shorter than MS occurring in APL relapse. To date, a total of 28 cases of APL with MS as the initial presentation have been reported worldwide. The tumor was removed. Continuous complete remission was achieved after the treatment of all-trans retinoic acid (ATRA) + arsenic trioxide (ATO). After radiotherapy or tumor resection, ATRA + ATO showed a favorable therapeutic response for both APL and MS.