A rare case of a concomitant ovarian fibroma and malignant steroid cell tumor: insights into pathogenesis and steroidogenesis.

backgroundFibromas are common ovarian stromal tumors, while steroid cell tumors (SCTs) are rare, accounting for < 0.1% of ovarian neoplasms. Approximately, one-third of SCTs exhibit malignant behavior, but predicting malignancy remains challenging. CASE PRESENTATION: A 73-year-old woman presented with nonspecific pelvic pain, and imaging revealed multiple pelvic masses. She underwent a simple hysterectomy and bilateral adnexectomy. Pathological examination revealed a unique colocalization of a fibroma and a SCT in the right ovary. One year later, the SCT recurred with lymph node metastasis. Morphological analysis and whole exome sequencing suggested a shared origin for the fibroma and SCT components. Notably, two missense mutations in MUC4 were identified in the SCT, with immunohistochemistry confirming MUC4 overexpression. Steroidogenesis patterns in the SCT resembled those of adrenocortical carcinoma, indicating disorganized steroidogenesis and potentially explaining the absence of clinical endocrine abnormalities.

conclusionThis case underscores the rarity and complexity of concomitant ovarian fibroma and malignant SCT. The identification of MUC4 mutations and disorganized steroidogenesis may provide insights into the pathogenesis of malignant SCTs. Further research is needed to understand the mechanisms and clinical implications of malignant SCT.