Clear‑cell variant renal cell carcinoma with leiomyomatous stroma: World Health Organization new entity

Abstract

Renal cell carcinoma (RCC) represents about 3% of all newly diagnosed cancers in the United States and
accounts for 85% of renal cancers in adults. These are approximately 65,000 new cases per year and 13,000
deaths from the disease. RCC with leiomyomatous stroma is an emerging entity. The risk factor and etiology
of RCC were obesity, smoking, hypertension, acquired cystic kidney disease, and occupational exposure
like trichloroethylene. Most of the RCC are sporadic, 2%–4% have a familial cause. In this study, 62 years’
male patient comes with flank pain, flank mass on the right side, and hematuria, on imaging shows solid
and homogeneous to heterogeneous with cystic area and hemorrhage. Histopathological features show
the nest of tumor cells with clear cytoplasm arranged in an alveolar and acinar pattern having conspicuous
nucleoli surrounded by abundant vascular and smooth muscle stroma. On the basis of histological and
immunohistochemistry studies, findings were suggestive of clear-cell RCC Grade 2 with leiomyomatous
stroma.