Fumarate hydratase (FH)-deficient uterine leiomyomas represent 1% of all uterine leiomyomas. They show distinctive morphology, and are often associated with a loss of expression of FH protein, secondary to the inactivation of the FH gene. They can occur sporadically or in the hereditary setting of hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome associated with germline mutations of FH gene. So, it is relevant to consider this diagnosis in case of young women with numerous or bulky leiomyomas and evocative microscopic features, in particular at nuclear level. Genetic screening is essential to identify hereditary forms, which require appropriate surveillance and genetic screening of relatives. Here, we report the case of a 20cm uterine leiomyoma in a young 32-year-old woman, whose morphologic and immunohistochemical characteristics were suggestive of FH-deficient leiomyoma.
