Clinicopathological and molecular features of so-called low-grade oncocytic fumarate hydratase-deficient renal cell carcinoma: a study of 5 cases.

ABSTRACT: Low-grade oncocytic fumarate hydratase-deficient renal cell carcinoma (FHdRCC), resembling succinate dehydrogenase-deficient RCC morphologically, is a recently described uncommon variant of FHdRCC. We report five additional cases to enhance the understanding of this rare tumor type. These tumors had variably thick fibromuscular capsules with frequent intracapsular invasions and had prominently compact nests and/or tubules. The tumor cells were characterized by abundant dense eosinophilic cytoplasm imparting a ground glass-like appearance and by variable bubbly cytoplasm. Despite a predominantly low histology grade, focal nuclear pleomorphism was observed in two cases. Two cases showed FH negativity and 2SC positivity, while the remaining cases exhibited both FH and 2SC positivity. All case

SUBMITTER: Xie B 

PROVIDER: S-EPMC12391247 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature