Acquired cystic disease–associated renal cell carcinoma with sarcomatoid change and rhabdoid features

Acquired cystic disease (ACD)–associated renal cell carcinoma (RCC) is a recently described entity. To the best of our knowledge, there are no reports of ACD-associated RCC with sarcomatoid and rhabdoid changes. In this article, we present the first case of such a tumor. A 56-year-old Japanese man has received long-term hemodialysis and had a history of right renal cancer. Following the discovery of metastatic cancer in the thoracic wall, detailed imaging studies revealed a mass in the left kidney. The histologic examination of the left renal tumor showed ACD-associated RCC with sarcomatoid change and rhabdoid features. Immunohistochemically, intracytoplasmic globular inclusions in rhabdoid cells were positive for vimentin and cytokeratin CAM5.2. The G-band karyotype showed the following changes: 46, X, +X. −Y[1]/43, idem, add(2)(q31), −6, −9, −14, −15, +16, −22, +mar1[6]/46, XY[2]/abnormal cell[11]. In conclusion, pathologists and urologists should be aware that rhabdoid features may occur in ACD-associated RCC and that the loss of chromosomes 9 and 14 may occur during the process of sarcomatoid change in ACD-associated RCC.