Implications of Fumarate Hydratase Deficiency (FHD) and Cancer Risk: A Window into the Clinical and Oncological Implications of a Rare Disorder in Gynecology.

Fumarate hydratase (FH) deficiency is a rare, yet impactful metabolic disorder caused by mutations in the FH gene, affecting the Krebs cycle, leading to the accumulation of fumarate and pseudohypoxic states. This metabolic shift promotes cell signaling alterations that can drive tumorigenesis, as heterozygous germline mutations in the FH gene, resulting in hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome. FH-deficient uterine leiomyomas show peculiar histological features that may lead to misdiagnosis STUMP (smooth muscle tumor of uncertain malignant potential) and uLMS (uterine leiomyosarcoma). Definitive diagnosis involves clinical evaluation, imaging, and histopathological examination, with immunohistochemistry for FH protein being a key diagnostic tool. Management of FH-deficient leiomyomas may involve conventional treatments like surgery and hormonal therapy but also requires careful monitoring and genetic counseling for associated malignancies. High-intensity focused ultrasound (HIFU) has emerged as a promising treatment option for fibroids, although long-term efficacy remains a concern also because of its inability to obtain tissue for a pathological diagnosis. Fumarate hydratase deficiency (FHD) represents a significant challenge in gynecologic oncology due to its association with an increased risk of hereditary leiomyomatosis and renal cell carcinoma. Nevertheless, to the best of our knowledge, there is a lack of studies demonstrating the potential role of FH deficiency in increased risk of leiomyosarcomatosus transformation. Early detection, genetic screening, and personalized treatment approaches are critical for improving patient outcomes. The aim of this review is to develop a narrative overview of the implications of FHD in gynecological diseases and its correlation with cancer risk. For the first time, this review offers an overview of the necessity for studies to address the possible correlation between FH deficiency and the risk of developing leiomyosarcoma, focusing on new perspectives that can be explored in the field of better FH deficiency knowledge and cancer risk.