Ipsilateral retroperitoneal papillary renal cell carcinoma 27 years after simple nephrectomy for a renal abscess: A case report

Abstract

BACKGROUND

Cases of severe inflammatory renal disease and renal cell carcinoma (RCC) that occur simultaneously in the same kidney have been occasionally reported. However, extrarenal RCC that does not originate from the native kidney has rarely been reported. To our knowledge, this is the first reported case of RCC developing in the ipsilateral retroperitoneal space after a simple nephrectomy (SN) for inflammatory renal disease.

CASE SUMMARY

A 63-year-old woman was referred to our hospital following the incidental discovery of a left retroperitoneal mass without specific symptoms. Her medical history revealed a left SN 27 years ago due to a renal abscess. Magnetic resonance imaging of the abdomen revealed three oval masses in the left retroperitoneum. The masses were successfully excised, and subsequent pathology confirmed papillary RCC. After surgery, the patient remained disease-free for 11 years without adjuvant therapy.

CONCLUSION

Clinicians should be vigilant of RCC in patients with retroperitoneal masses, especially after SN for inflammatory renal disease.

Key Words: Abscess, Papillary renal cell carcinoma, Nephrectomy, Adhesiveness, Case report

Core Tip: To date, no cases of renal cell carcinoma (RCC) arising in the ipsilateral retroperitoneum following simple nephrectomy (SN) have been reported. We aimed to share our experience of treating RCC in the ipsilateral retroperitoneum of a 63-year-old Asian woman who underwent SN for a renal abscess 27 years ago. When evaluating retroperitoneal masses in patients with a positive clinical history of SN, clinicians should consider the possibility of late-onset RCC as a differential diagnosis.

INTRODUCTION

The synchronous occurrence of renal malignancies and inflammatory conditions such as xanthogranulomatous pyelonephritis in the same kidney is rare but has been reported occasionally[1-3]. However, late-onset and incidental detection of renal cell carcinoma (RCC) in the ipsilateral retroperitoneum following simple nephrectomy (SN) is a novel finding. When performing SN on a severely inflamed kidney harboring undiagnosed renal cancer, a risk of tumor cell spillage and inoculation in the peritoneal cavity exists. On the other hand, extrarenal RCC is extremely rare and has only been reported eight times in the literature. In all cases, the patients had intact bilateral kidneys, and the masses were located very close to the native kidney, presenting with a single cancer cell type[4-8]. Herein, we report a unique case of extrarenal papillary renal cell carcinoma (PRCC) located in the ipsilateral retroperitoneum 27 years after SN for the treatment of a renal abscess.

CASE PRESENTATION

Chief complaints

A 63-year-old Asian woman was referred to our hospital on April 23, 2013, following the incidental detection of a left retroperitoneal mass on abdominal computed tomography (CT).

History of present illness

CT findings obtained during health screening revealed three lesions in the left retroperitoneum. The patient was referred to our clinic for further evaluation and disease management, with no reported specific symptoms or pain.

History of past illness

Her medical history included a left SN due to a renal abscess 27 years ago and a cesarean delivery 41 years ago. At the time of SN, she was admitted to the intensive care unit for 3 d because of massive intraoperative bleeding. The surgeon informed the patient that the nephrectomy was performed incompletely because of severe perinephric inflammation and intraoperative bleeding.

Personal and family history

There was nothing remarkable in the patient's personal and family history.

Physical examination

No positive signs were observed on abdominal, cardiopulmonary, or nervous system examinations.

Laboratory examinations

The results of routine laboratory tests, including complete blood count, liver and kidney function tests, and urine analysis, were normal.

Imaging examinations

Magnetic resonance imaging of the abdomen revealed three oval masses in the left retroperitoneum (2.8 cm, 5.0 cm, and 6.0 cm, respectively) (Figure 1). The T2-weighted coronal image exhibited a high signal intensity and demonstrated a well-enhanced pattern. Diffusion-weighted transverse imaging showed a mildly restricted diffusion. The results of chest CT and bone scintigraphy for detecting metastasis were unremarkable.

Figure 1 Magnetic resonance imaging of the abdomen. A: The T2-weighted coronal image shows three distinct oval masses in the left retroperitoneum (indicated by orange arrows), exhibiting a high signal intensity and a well-enhanced pattern; B: The image on the left displays diffusion-weighted transverse images of three retroperitoneal masses (indicated by orange arrows), while the image on the right shows the corresponding gross features of three specimens. The diffusion-weighted transverse images reveal mild restricted diffusion.

FINAL DIAGNOSIS

Considering the above-mentioned clinical data and the absence of a history of RCC, the patient was diagnosed with multiple solitary fibrous tumors.

TREATMENT

Following a detailed discussion, we decided to perform open surgery. Mild tissue adhesion was observed between the descending colon and the three retroperitoneal masses located in the psoas muscle between lumbar vertebral levels 1 and 4. The masses had clear boundaries with the surrounding tissue; therefore, complete resection was not difficult (Figure 2). The postoperative course was uneventful.

Figure 2 Intraoperative findings show a distinct, well-demarcated round mass (black arrow) after dissecting the descending colon (white arrow).

OUTCOME AND FOLLOW-UP

Immunohistochemical results showed diffuse cytoplasmic positivity of the tumor tissues for pan-cytokeratin, vimentin, epithelial membrane antigen, cytokeratin 7, and α-methylacyl coenzyme A racemase (Figure 3). Microscopic findings of hematoxylin and eosin (H&E) staining showed tubulopapillary structures lined by large eosinophilic epithelial cells with high-grade nuclear features and small basophilic cuboidal cells with low-grade nuclear features (Figure 4). The final pathological report was PRCC, according to the 2022 World Health Organization classification. The patient refused adjuvant treatment. She underwent follow-up evaluations every 3 months for the first year, then every 6 months for the next 5 years, and annually thereafter. During the initial 5-year period, abdominopelvic and chest CT scans, along with complete blood count examinations, liver and kidney function tests, and urine analysis were conducted every 6 months, supplemented by an annual bone scan. Subsequent to 6 years post-surgery, the same tests were conducted annually. She visited our hospital on February 13, 2024 and has remained disease-free for 11 years post-surgery.

Figure 3 Immunohistochemical results (×100). A: Tumor cells show diffuse cytoplasmic positivity for pan-cytokeratin; B: Vimentin; C: Cytokeratin 7; D: α-methylacyl coenzyme A racemase.

Figure 4 Microscopic findings of hematoxylin and eosin staining. A: Tubulopapillary structures with some microcystic changes (×100); B: Papillary structures associated with accumulation of foamy histiocytes (×100); C: Tubulopapillary structures lined by eosinophilic epithelial cells with high-grade nuclear features of Fuhrman nuclear grade 3-4 (×200); D: Psammomatous calcific bodies scattered over tubular lumina and interstitial stroma (×200).

DISCUSSION

To the best of our knowledge, no cases of RCC occurring in the ipsilateral retroperitoneum following SN for benign renal disease have been reported. There are three possible explanations for this unique occurrence. First, extrarenal RCC, which is believed to arise from mesonephric remnants, occurs after SN[4]. It is a rare disease with no anatomical connection to the native kidney[4]. Previous case reports have indicated that both kidneys were intact and that extrarenal RCC was present on one side of the body, located very close to a native kidney; however, this case presented with one intact kidney and three separate tumor masses in the contralateral retroperitoneum. We speculated that if there was no retroperitoneal mass at the time of SN, the mesonephric remnants may have slowly progressed to extrarenal RCC after SN.

The second possibility is tumor seeding from unrecognized RCC and indolent growth of tumor spills. While inflammatory renal disease has been reported alongside RCC in some cases, this association does not imply a general correlation between benign inflammatory renal disease and RCC. Rather, instances where inflammatory renal disease and RCC coexist within the same kidney have been documented on several occasions[8-10]. The association between renal malignancies and pyelonephritis can lead to misinterpretation, even in the modern era of imaging procedures, and it is sometimes difficult to preoperatively distinguish inflammatory renal disease from RCC. SN is performed safely and is uncomplicated in kidneys without renal anomalies or inflammation. However, inflammation associated with pyelonephritis can make SN more complicated and difficult to perform than radical nephrectomy[7]. Poor surgical conditions and a rough surgical technique that violates primary tumor boundaries can promote seeding. If our patient had a concomitant renal abscess and malignancy in the same kidney, tumor cell spillage or direct inoculation with neoplastic cells could have occurred.

Third, the tumors may have originated from the residual renal parenchyma due to incomplete resection of the left kidney, a scenario not previously reported. The dense and fibrotic tissue of the perinephric and perihilar areas can pose significant challenges in dissection and accidental organ or vascular injury due to obliteration and adhesion of regular tissue planes. In the medical history review, the patient in question had been unable to undergo a complete excision of the left kidney because of complications that occurred during surgery. Consequently, the remaining left renal tissue may not have regressed naturally; thus, the possibility of transformation into RCC cannot be ruled out.

PRCC is the second most common type of RCC, accounting for 15%–20% of RCC cases. PRCC manifests with a heterogeneous clinical course, including multifocal, indolent presentations and solitary tumors with a highly aggressive pattern[11]. Generally, PRCC has a lower potential for metastasis than clear-cell RCC and a better prognosis in patients with non-metastatic RCC[12]; however, PRCC is more aggressive than clear-cell RCC in patients with metastatic disease[13]. There have been no reports of tumor seeding from kidneys with severe inflammation and unrecognized PRCC or of transformation from the residual kidney parenchyma to PRCC. To date, only three articles reporting primary extrarenal PRCC with a very short-term follow-up (< 2 years) have been published[14-16]. In this case, three separate retroperitoneal masses were diagnosed as PRCC, which demonstrated favorable long-term oncological outcomes over a decade after surgery.

CONCLUSION

The late occurrence of ipsilateral retroperitoneal RCC after SN for the treatment of inflammatory renal disease is remarkable. Clinicians should consider the potential late occurrence of RCC in the differential diagnosis of retroperitoneal masses in patients with a positive clinical history of SN related to inflammatory renal disease.