Ossifying renal cell carcinoma

Abstract

In older children, ossifying renal cell carcinoma is a potential explanation for a network of well-organized, curvilinear high-attenuation areas in a renal mass. Since ossification of renal cell carcinoma is a favorable tumor marker that implies a less extensive resection, it is important to anticipate this tumor before surgical resection is undertaken.

Ossification of renal cell carcinoma: a favorable marker

“…Unlike other cases in the literature, neither ossification nor calcification of RCC was observed in any preoperative imaging studies such as plain X-ray , CT scan, or MRI. To our knowledge, it is the first ossifying RCC case published in the English literature that was diagnosed initially on pathologic examination [1][2][3][4][5]. In contrast to the previously reported cases, the tumor in our case was not relatively large and did not contain any bone marrow elements [1][2][3][4][5].…”

“…Although the first case was reported in 1938, its mechanism is still unclear [2][3][4]. However, in their case report Yamasaki et al suggested that ossification in RCC may result from the metaplasia of pluripotent stem cells into osteoblastic cells by the mechanism of paracrine secretion of bone morphogenetic protein 2 (BMP-2) from the tumor cells, like gastrointestinal tract glandular tumors with ossification [5].…”

“…To our knowledge, it is the first ossifying RCC case published in the English literature that was diagnosed initially on pathologic examination [1][2][3][4][5]. In contrast to the previously reported cases, the tumor in our case was not relatively large and did not contain any bone marrow elements [1][2][3][4][5]. Positive immunohistochemical staining with both cytokeratin, vimentin, EMA together with the hematoxylin-eosin staining findings support the diagnosis of RCC with osseous metaplasia.…”

“…Although foci of calcification in renal cell carcinoma (RCC) is frequently observed, ossification is extremely rare and it has been suggested to be a marker for favorable prognosis, since there is typically no tumor invasion beyond the gross margin of the ossified RCC [1,2]. If ossification is detected before or during surgery, then a less radical surgery, such as partial nephrectomy, might be considered [2].…”

“…If ossification is detected before or during surgery, then a less radical surgery, such as partial nephrectomy, might be considered [2].…”