Expanding morphological and clinical aspects of hereditary leiomyomatosis and renal cell carcinoma (HLRCC): a case report in a patient with unusual morphology and clinical presentation.

Renal cell carcinoma (RCC) accounts for 2-3% of all malignant disease in adults. Hereditary RCC represents 5 to 8% of kidney tumors. Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) represents an autosomal dominant syndrome that results from a germline mutation in fumarate hydratase gene (FH). HLRCC patients typically present with skin or uterine leiomyomas and renal neoplasms. HLRCC was recently recognized as a distinct renal tumor subtype by the WHO 2016 classification. Many morphological patterns such as papillary, solid, tubular, and cystic had been described as part of morphological aspects of HLRCC. In this study, we describe a case of a patient that had a history of persistence of ductus arteriosus (PDA) and cryptorchidism. In addition, the renal tumor showed a very unusual hystiocytoid morphological aspect. We confirmed the presence of a FH germline mutation both in the patient and his mother.