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THECOMA OF THE OVARY

Female Genital Tract

THECOMA OF THE OVARY
Thecoma of the ovary is a type of ovarian tumor that is classified as a benign sex cord-stromal tumor. These tumors are composed of specialized stromal cells, which produce estrogen, and they can sometimes present with hormonal effects, such as abnormal bleeding due to their estrogenic activity. Let's break down the details of thecoma, including its gross and microscopic appearance:

1. Clinical Features:
• Age group: Thecoma is most commonly found in postmenopausal women, though it can also occur in younger women, including those of reproductive age.
• Symptoms:
o Hormonal effects: Thecoma cells secrete estrogen, leading to symptoms like endometrial hyperplasia, postmenopausal bleeding, and sometimes precocious puberty in younger women.
o Mass effect: Some tumors can become large and cause abdominal swelling, pain, or discomfort.
o Luteinization: Occasionally, the tumor may show signs of luteinization, leading to a functional cystic appearance.

2. Gross Appearance:
• Size and shape: Thecoma typically presents as a solid, well-circumscribed, round or oval mass. It is usually small to moderate in size but can sometimes be larger, especially in cases where it produces hormonal symptoms.
• Color: The tumor usually appears yellow or yellow-brown in color. The yellow color is due to the presence of lipid-filled stromal cells, which are characteristic of this tumor.
• Surface: The surface of the tumor is smooth or slightly nodular.
• Consistency: On palpation, the tumor feels firm, and it can sometimes be lobulated. It does not typically have cystic areas unless associated with luteinization or hemorrhage.

3. Microscopic Appearance:
• Tumor cells: Thecoma consists of spindle-shaped stromal cells arranged in a fascicular (bundled) pattern. These cells have a moderate amount of cytoplasm and may contain lipid droplets, which give them a yellowish appearance. The tumor cells have round to oval nuclei with prominent nucleoli, and the cytoplasm is often eosinophilic (pink) due to the lipid content.
• Stromal background: The tumor is composed predominantly of fibrous stroma that may be fibromatous or myxoid (a gelatinous consistency).
• Vascularity: There may be increased vascularity, and some tumors show a prominent network of blood vessels. However, large blood vessels are not typically present.
• Calcifications: Sometimes, areas of dystrophic calcification may be present, especially in older patients.

• Hormonal activity: If thecoma is producing estrogen, there may be associated changes in the endometrium, such as endometrial hyperplasia, which can be seen microscopically in biopsies of the uterus.
4. Immunohistochemistry:
• Thecoma cells typically express inhibin, calretinin, and estrogen receptors (ER), which are markers of sex cord-stromal tumors. CD99 may also be expressed, and the tumor is generally negative for epithelial markers (like cytokeratin).
• Luteinization: If luteinization occurs, the tumor cells may show immunoreactivity for progesterone receptors (PR).
5. Differential Diagnosis:
• Fibroma: Fibromas are another type of ovarian sex cord-stromal tumor. They are similar in appearance to thecoma but lack the prominent yellow color and estrogen-producing potential. Thecoma has more lipid-rich cells than fibromas.
• Granulosa cell tumor: This is another ovarian tumor that can produce estrogen, but granulosa cell tumors are composed of more granulosa-like cells and have a different microscopic appearance.
• Sertoli-Leydig cell tumor: This tumor type may also be hormonally active but is composed of Sertoli and Leydig cells, and typically presents with virilization in contrast to the estrogenic effects of thecoma.
6. Diagnosis and Management:
• Imaging: Ultrasound and CT/MRI scans are commonly used to identify ovarian masses. Thecoma typically appears as a solid mass with a homogeneous echo pattern.
• Hormonal evaluation: In cases where hormonal symptoms are present, measuring serum estrone levels (since thecoma secretes estrogen) can help support the diagnosis.
• Surgical excision: Thecoma is generally treated with surgical excision, and since it is benign, prognosis after removal is excellent.
• Follow-up: Long-term follow-up is often recommended to ensure no recurrence, but it is rare.
In summary, thecoma of the ovary is a benign tumor that can present with hormonal effects due to estrogen production. It typically appears yellow on gross examination and is composed of spindle-shaped, lipid-laden stromal cells on microscopy. Treatment is usually surgical, and prognosis is favorable.

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