Germline BRCA1変異を有する患者における予防的卵管卵巣摘出術での偶発的なBリンパ芽球性白血病/リンパ腫

B-lymphoblastic leukemia/lymphoma (B-ALL) is a malignant neoplasm of immature B lymphocytes. Occasionally, B-ALL may exhibit morphological and immunophenotypic overlaps with other hematologic malignancies such as B-ALL with isolated myeloperoxidase (MPO) expression which may complicate diagnosis. BRCA1 and BRCA2 are tumor suppressor genes involved in homologous recombination and DNA repair. While germline mutations in these genes are well-established risk factors for breast and ovarian cancers, the association between BRCA1/2 mutations and hematologic malignancies remains underexplored. We present a rare case of B-ALL with isolated MPO expression, discovered incidentally in prophylactically resected ovaries of a patient with a germline BRCA1 mutation, and review the literature exploring this potential association.