Chromophobe Renal Cell Carcinoma with Osseous Metaplasia: a Case Report

Abstract

A 60-year-old Japanese male with a chromophobe cell carcinoma of his left kidney is reported. The tumor, 18 x 27 mm in size, was incidentally found by abdominal ultrasonography. Computed tomography and magnetic resonance imaging demonstrated a well-demarcated solid tumor arising from the lower pole of the left kidney. Histopathological examination of the surgically removed tumor revealed that it was composed of solid sheets of cancer cells having abundant and slightly eosinophilic reticular cytoplasm with accentuated cell membranes making up a plant cell-like appearance. Electron microscopic examination demonstrated numerous intracytoplasmic microvesicles. Although the tumor cells were positive for cytokeratin and epithelial membrane antigen, they did not show vimentin immunoreactivity. The unique histological finding of this tumor from other reported renal chromophobe carcinomas was that it had a peripheral fibrotic area with a focus of metaplastic ossification.

Renal cell carcinoma with osseous metaplasia: A case report and literature review

“…Osseous metaplasia has also been reported in patients with renal diseases, including less than 20 cases of the major subtypes of RCC [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][23][24][25][26]. Table 1 summarizes clinicopathologic features of these cases, including the present case, reported in case studies of osseous metaplasia associated with RCC.…”

“…Sarcomatoid differentiation is also seen in a subset of RCCs and is generally associated with poor patient outcomes. By contrast, metaplastic bone formation with or without bone marrow elements in RCC is extremely rare yet has been reported predominantly in clear cell [2][3][4][5][6][7][8][9][10][11][12] and chromophobe [13][14][15][16] subtypes. We here present a case of papillary RCC with osseous metaplasia along with a review of the literature on this unusual condition.…”

Chromophobe renal cell carcinoma: A report of two cases with unusual histological features

“…Although calcification is known to occur in RCCs, reports of extensive ossification in CRCC are rare, with only two reports to date. [78] The ossification was present in the fibrous stroma in all the cases. The histogenesis is considered to be from stromal osseous metaplasia.…”

Chromophobe renal cell carcinoma with calcification: Report of a case with rare finding on aspiration smears

“…9 Yokozaki et al reported a case of ChRCC with osseous metaplasia on histopathological examination of a nephrectomy specimen. 10 The literature regarding the cytological diagnosis of clear cell (conventional) renal cell carcinoma is abundant but there have been only a few reports regarding the diagnosis of Chromophobe RCC. To the best of our knowledge, this is the 18th case of ChRCC among the published literature and is the only case highlighting the presence of calcification in aspiration smears.…”