Mural nodules are rare findings in ovarian mucinous tumors and may represent either benign or malignant components. Distinguishing Sarcoma-Like Mural Nodules (SLMNs) from malignant mural nodules is essential because management and prognosis differ substantially. We report a 25-year-old woman with a left ovarian mucinous borderline tumor containing a 2×2×1 cm polypoid mural nodule. Grossly, the nodule was dark brown with areas of necrosis and fibrin. Microscopically, it was well-circumscribed and composed of patternless spindle cells with moderate to marked pleomorphism, hyperchromatic, and prominent nucleoli. Abnormal mitoses and blood-filled spaces were present, without stromal invasion or lymphovascular involvement. Sarcoma-like mural nodules may mimic malignant lesions but typically occur in younger patients and generally show benign behavior. In this case, the histological and macroscopic features supported the diagnosis of a sarcoma-like mural nodule arising in a mucinous borderline ovarian tumor.
Betty et al. (2026) studied this question.