Mucinous adenocarcinoma of the renal pelvis masquerading as xanthogranulomatous pyelonephritis

Primary mucinous adenocarcinoma of the renal pelvis misdiagnosed as calculous pyonephrosis: a case report and literature review

Primary mucinous adenocarcinoma of the renal pelvis is a rare malignant disease that is difficult to diagnose preoperatively. There are still no characteristic symptoms, radiological features, or standard treatment for this tumor with only ~100 cases reported. The prognosis is poor. We report a case of a 66-year-old man who presented with a 2-month history of fever and right waist pain. He was misdiagnosed with calculous pyonephrosis and underwent percutaneous nephrostomy (PCN) at a local hospital. Gelatinous material was drained via a PCN catheter. He was then transferred to our hospital. He had elevated CEA and CA19-9. We performed an open radical nephrectomy and found polypoid, gelatinous material and stones filling the renal pelvis. He was diagnosed with primary mucinous adenocarcinoma of the renal pelvis by pathology. He refused adjuvant chemotherapy and there was no sign of recurrence after one year of follow-up. By assessing a literature review of all of the cases reported since 2000, we recommend that careful history taking, serum tumor markers, and CT scans may improve the diagnostic accuracy rates and radical nephrectomy with total ureterectomy accompanied by adjuvant therapy may improve the prognosis.

Primary enteric-type mucinous adenocarcinoma of the renal pelvis masquerading as cystic renal cell carcinoma: A case report and review of the literature

Primary mucinous adenocarcinoma of the renal pelvis is easily misdiagnosed and it was rarely reported in the literature. We describe in this study a case of 40-year-old male patient presented with right lumbar pain of one year duration and elevated level of carcinoembryonic antigen (CEA). After a series of imaging examinations, the initial impression was a cystic renal cell carcinoma. Right radical nephrectomy was performed on the patient. The postoperative pathological examination indicated a primary mucinous adenocarcinoma of enteric type of the renal pelvis. After surgical removal of the tumor, an immunotherapy was administrated to prevent recurrence. The patient survives upon this report. A review of pertinent literature is also presented.

[Renal urothelial carcinoma mainly composed of signet-ring cells]

Autopsy study of an 80-year-old man has identified his renal tumor metastasizing to the heart, lung, and liver as urothelial car- cinoma; at the same time some cells in the main tumor and all cells in the metastases had a signet-ring phenotype, but neither mucicarcimine nor alcian blue stained the cell cytoplasm. The paper provides the histological and immunohistochemical pattern of the tumor and emphasizes its exclusive rarity. Attention is drawn to the possibility of signet-ring cell transformation in the cells of different tumors, including nonepithelial ones.