Primary mucinous cystadenocarcinoma of the renal pelvis misdiagnosed as ureteropelvic junction stenosis with renal pelvis stone: a case report and literature review

Abstract

BackgroundPrimary mucinous adenocarcinoma of the renal pelvis is extremely rare, with only ~100 cases reported till now. Its presumed pathogenesis includes glandular metaplasia of the urothelium of the calyces and the pelvis and malignant transformation of the metaplasia. Unfortunately, it has no characteristic symptoms or radiological features. We report a case of primary mucinous adenocarcinoma of the renal pelvis misdiagnosed as ureteropelvic junction stenosis with a renal pelvis stone.Case presentationA 50-year-old man presented with discomfort in his right flank after a fall. A physical examination was normal except mild costovertebral angle tenderness on the right side. The results of most laboratory tests were within normal limits. Plain radiography of the kidneys, ureter, and urinary bladder showed a large radio-opaque mass in the right kidney. Abdominal computed tomography showed a hyperdense mass with 2.62 × 5.70 cm size in the right renal pelvis and severe hydronephrosis and cortical thinning. Diuretic-enhanced 99mTc DTPA renal scanning showed that the relative function of the right versus the left kidney was 20 versus 80 %. On the basis of the imaging findings, kidney dysfunction due to ureteropelvic junction stenosis with a large stone was initially diagnosed.However, the drained urine volume was almost zero, and gelatinous material was aspirated when percutaneous nephrostomy was performed for decompression of hydronephrosis. Although the cytopathology of gelatinous material was negative for malignancy, we could not rule out other disease, such as hidden malignancies of the kidney.We therefore performed radical nephrectomy, and pathological examination of the kidney uncovered a mucinous cystadenocarcinoma in the renal pelvis. A bone scan and positron emission tomography showed no evidence of other malignancies, metastasis, or remnant cancer. The patient has been well, without evidence of tumour recurrence or metastasis, for 20 months after surgery.ConclusionsPrimary mucinous adenocarcinomas of the renal pelvis are extremely rare, and most are diagnosed via post-operative analysis of resected specimens. Although preoperative diagnosis is difficult, urologists should consider the possibility of primary mucinous adenocarcinoma in patients with severe hydronephrosis accompanied by renal stones and chronic inflammation

Primary enteric‐type tubulovillous adenocarcinoma arising in the renal pelvis

“…We would like to investigate the pathogenesis and pathophysiological mechanism(s) underlying the initiation and development of primary adenocarcinoma in the renal pelvis. In line with the previous description, this histopathological finding could potentially be induced by a long‐term chronic inflammatory reaction in the epithelium covering the urinary tract, especially reactions caused by pelvic calculi and/or hydrocalycosis/hydroureter, as occurred in our case. However, it is possible that long‐term inflammation did not affect the present urinalysis or histopathology.…”

“…first demonstrated the clinicopathological features of an extremely rare case of primary mucinous adenocarcinoma arising in the renal pelvis . Following that, a substantial number of interesting case reports describing the pathological features of primary pelvic adenocarcinoma were published; however, within our thorough investigation, we found less than 100 cases reported in the English literature, with most cases reported from Asian countries . Indeed, it is well‐known that transitional cell (urothelial) carcinoma accounts for up to 90% of epithelial‐origin malignancies arising from the renal pelvis, whereas adenocarcinoma accounts for less than 1% .…”

“…Following that, a substantial number of interesting case reports describing the pathological features of primary pelvic adenocarcinoma were published; however, within our thorough investigation, we found less than 100 cases reported in the English literature, with most cases reported from Asian countries . Indeed, it is well‐known that transitional cell (urothelial) carcinoma accounts for up to 90% of epithelial‐origin malignancies arising from the renal pelvis, whereas adenocarcinoma accounts for less than 1% . Pure adenocarcinomas of the renal pelvis are histopathologically classified as tubulovillous (71.5%), mucinous (21.5%), or papillary non‐intestinal (7.0%) .…”

“…Aggressive surgical treatment in the early stage of primary renal pelvic adenocarcinoma might be associated with a better prognosis, as this disease is associated with higher‐grade (i.e., invasive characteristics) malignant tumors, with a reported overall survival rate of <50% within 2 years after surgery . It is therefore critical to establish an accurate pre‐operative diagnosis based on urine cytology, the clinical utility of which has been generalized in the diagnosis of urinary tract tumors.…”

The expression of metastasis-associated in colon cancer-1 and KAI1 in gastric adenocarcinoma and their clinical significance

“…Indeed, KAI1, as a suppressor of tumor metastasis, could inhibit β-catenin tyrosine phosphorylation and stabilize E-cadherin-β-catenin complexes to suppress tumor metastasis [38]. In addition, KAI1 could inhibit the process of β-catenin-mediated EMT to prevent tumor angiogenesis and lymphangiogenesis [39]. Meanwhile, MACC1 could be bound to the promoter of the MET gene and activate the HGF/MET signaling pathway to promote cancer cell proliferation, invasion, and metastasis [3, 4].…”