Differential immunostaining of oncocytic renal tumors with an anti-renal cell carcinoma monoclonal antibody

Renal oncocytomatosis in a long-term hemodialysis patient treated by laparoscopic surgery

A 50-year-old female, who had been on maintenance hemodialysis for 22 years, consulted our clinic because of a left renal mass detected incidentally by ultrasonography. Computed tomography (CT) demonstrated a solid hypervascular mass, suggesting a renal cell carcinoma (RCC), in the left atrophic kidney. Left hand-assisted laparoscopic nephrectomy (HALN) was performed. The histopathological diagnosis was renal oncocytomatosis. Renal oncocytomatosis in a long-term hemodialysis patient is extremely rare. We report the first case of renal oncocytomatosis in a long-term hemodialysis patient treated with hand-assisted laparoscopic nephrectomy.

Renal oncocytoma: clinical and biological correlates

We treated 31 patients with renal oncocytoma. Renal cell carcinoma was found existing separately within the same or contralateral kidney in 10 patients (32%). Followup of 29 patients revealed 24 alive with no evidence of disease and 1 alive with recurrent oncocytoma, while 1 with coexistent tumors died of progressive renal cell carcinoma and 3 tumor-free patients died of unrelated diseases. Quantitative deoxyribonucleic acid analysis was performed on cell suspensions of fresh tumor by flow cytometry or by image cytometry on touch preparations from frozen tissue in 16 patients with renal oncocytoma. Ploidy analysis revealed all oncocytomas to be diploid. Frozen tissue immunohistology was performed using murine monoclonal antibody against human HLA-A, B and C (class I) antigens with the avidin-biotin peroxidase technique in 11 patients with renal oncocytoma. Ten oncocytomas did not express these self-recognition antigens and 1 was only weakly positive for antigen expression. In contrast, renal cell carcinomas strongly expressed HLA class I antigens. The high incidence of coexistence of renal oncocytoma and renal cell carcinoma has important clinical implications. Loss of HLA class I antigen expression by renal oncocytomas may provide an additional method for differentiating this lesion from renal cell carcinoma.

Renal oncocytomas--an Australian experience

A review was made of 24 cases of renal oncocytoma seen between 1978 and 1989. There was considerable overlap between the clinical presentation of renal oncocytomas and renal carcinomas. Although pre-operative radiological, cytological and pathological investigations may suggest the presence of an oncocytoma, these studies cannot make a definitive diagnosis. We recommend that these tumours be treated as potential renal carcinomas until post-operative microscopic evaluation proves otherwise.