luteoma

luteoma refers to a rare benign ovarian tumor composed of luteinized stromal cells. It typically presents in late pregnancy, although cases have been reported outside of gestation and in neonatal patients. The tumor is most commonly unilateral and appears as a solid, cystic, or mixed mass on imaging. Clinical manifestations are variable; some patients are asymptomatic, while others experience abdominal pain, McKusick–Kaufman syndrome‐like features, or, in pregnant women, premature labor or gestational hypertension. In female fetuses, luteoma of the uterus or ovary can cause hyperandrogenism, leading to virilization and ambiguous genitalia.

Histologically, luteoma shows sheets of spindle‐shaped luteinized cells with eosinophilic cytoplasm and inconspicuous nucleoli. Immunohistochemistry is typically positive for inhibin, calretinin, and SF-1, while cytokeratin and EMA are usually negative, helping to differentiate it from granulosa‑cell tumors and metastatic carcinoma. Diagnostic imaging such as ultrasound, CT, or MRI may reveal a hypoechoic or heterogenous mass; however, definitive diagnosis requires tissue sampling.

Management is generally conservative, especially in pregnancy, because regression often occurs postpartum. Surgical resection is reserved for symptomatic or enlarging masses, malignant‑looking lesions, or when definitive diagnosis is uncertain. Prognosis is excellent; recurrence is rare, and malignant transformation has not been documented. Follow‑up imaging and hormonal monitoring are advised during and after pregnancy due to the tumor’s hormonal activity.