Granulosa cell tumor (GCT) is the most common subtype of ovarian sex cord-stromal tumors, accounting for 2-5% of all ovarian malignancies. It produces estrogen and is associated with endometrial hyperplasia/carcinoma. Presents as a solid-cystic mass on imaging; the adult type shows the characteristic 'sponge/Swiss cheese' pattern (multiple small cystic areas within solid background). Usually unilateral with indolent clinical course, but requires long-term follow-up due to late recurrences (20-30%, 5-20 years later). Inhibin B and AMH elevations are diagnostic markers.
Age Range
40-70
Peak Age
55
Gender
Female predominant
Prevalence
Rare
Granulosa cell tumor originates from granulosa cells of ovarian follicles. These cells physiologically produce estrogen — the tumor maintains this property and secretes autonomous estrogen. Estrogen excess leads to endometrial stimulation (25-50% endometrial hyperplasia, 5-10% endometrial carcinoma). FOXL2 gene mutation (C134W) is detected in >95% of adult-type GCTs and is pathognomonic for diagnosis. The micro-macrofollicular structure of the tumor (Call-Exner bodies) determines the 'sponge/Swiss cheese' pattern on imaging: multiple small cystic areas (follicular spaces or hemorrhage) are present within solid tumor background. Hemorrhage tendency is high — may present with acute abdomen. The solid component appears hypointense on T2 because fibrous stroma and tight cellular packing reduce free water content.
Visualization of scattered multiple small cystic areas within a solid background in a solid-cystic ovarian mass. This pattern reflects the tumor's micro-macrofollicular structure (Call-Exner bodies) and focal hemorrhage/necrosis areas. Highly characteristic of GCT and helps distinguish from other ovarian tumors (epithelial, germ cell). Confirmed on T2 MRI as hyperintense cystic foci within hypointense solid background.
US shows multiple small cystic/anechoic areas within a solid-cystic mass — 'sponge' or 'Swiss cheese' pattern. Solid background is of intermediate echogenicity. Cystic areas represent follicular spaces or hemorrhage areas of the tumor. Mass is usually unilateral, well-defined, and 5-15 cm in size.
Report Sentence
A solid-cystic mass is identified in the ovarian location with multiple small cystic areas within solid background ('sponge/Swiss cheese' pattern); granulosa cell tumor should be the primary consideration.
T2-weighted MRI shows hypointense solid component (due to fibrous stroma). Cystic/follicular spaces appear as T2-hyperintense foci. This combination of T2-hyperintense cystic foci within T2-hypointense solid background is the MRI equivalent of GCT. Hemorrhagic areas show variable T2 signal (depending on methemoglobin values in subacute hemorrhage).
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The solid component shows hypointense signal on T2-weighted sequences with multiple small T2-hyperintense cystic foci within, consistent with granulosa cell tumor pattern.
T1-weighted MRI shows high signal areas within the mass — hemorrhage. Subacute hemorrhage (methemoglobin) produces hyperintense signal on T1. Hemorrhage is a frequently accompanying finding of GCT and may lead to presentation with acute abdomen. Signal preservation on fat-suppressed sequences confirms hemorrhage (fat signal is suppressed, hemorrhage is not).
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High signal areas are observed within the mass on T1-weighted sequences with signal preservation after fat suppression, consistent with intratumoral hemorrhage, a commonly associated finding in granulosa cell tumor.
Contrast-enhanced MRI shows moderate to intense enhancement of solid component. Cystic/hemorrhagic areas show no enhancement. Enhancement pattern may be homogeneous or mildly heterogeneous. Does not show as aggressive enhancement as serous carcinoma — this reflects GCT's lower vascular density.
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Moderate enhancement is observed in the solid component on contrast-enhanced MRI without enhancement in cystic/hemorrhagic areas.
Endometrial thickening accompanying an ovarian mass is an important concurrent finding for GCT. In postmenopausal women, endometrial thickness >8 mm (some sources >5 mm); in premenopausal women, prominent thickening not matching secretory phase is suspicious. Endometrial hyperplasia or polyp may accompany. In rare cases, endometrial carcinoma may develop due to estrogen stimulation (5-10%).
Report Sentence
Endometrial thickening (... mm) accompanying the ovarian mass is observed, favoring an estrogen-producing ovarian tumor (granulosa cell tumor).
CT shows a solid-cystic mass. Solid component is at soft tissue density with moderate enhancement. Cystic areas are at water or hemorrhage density. Acute hemorrhage shows high density (50-70 HU). Mass is usually well-defined and unilateral. Peritoneal dissemination is rare, distinctly different from serous carcinoma.
Report Sentence
A solid-cystic mass is identified in the ovarian location on CT with high-density areas (hemorrhage) within; granulosa cell tumor should be considered in the differential diagnosis.
Criteria
95% of all GCTs. Common in peri/postmenopausal women (mean age 50-55). FOXL2 C134W mutation >95%. Call-Exner bodies and 'coffee-bean' nuclei are diagnostically histological.
Distinct Features
Classic 'sponge/Swiss cheese' pattern. Indolent clinical course, late recurrences (5-20 years). Stage I has 90-95% 5-year survival. Inhibin B and AMH markers used in follow-up.
Criteria
5% of all GCTs. Usually under 30 years (mostly prepubertal). Does not carry FOXL2 mutation. More solid appearance, less follicular pattern, more atypical cytology.
Distinct Features
More solid-dominant appearance on imaging, less 'sponge' pattern. In prepubertal children, may present with isosexual precocious puberty (early breast development, uterine bleeding). Prognosis is generally better than adult type — cure rate in stage I exceeds 95%.
Criteria
Massive intratumoral hemorrhage or hemoperitoneum from tumor rupture. Presents with acute abdomen in 10-15% of cases.
Distinct Features
Hemorrhagic areas with high density (CT) or T1-hyperintense (MRI) within the mass on imaging. Free peritoneal fluid (hemoperitoneum) may accompany. Must be differentiated from ruptured ectopic pregnancy, ovarian torsion, or hemorrhagic cyst. GCT should be considered when inhibin B and endometrial thickening on USG are present.
Distinguishing Feature
Ovarian fibroma is entirely solid, markedly T2-hypointense (fibrous tissue), and contains no cystic component. GCT has cystic areas within solid background ('sponge' pattern). Fibroma does not produce estrogen, no endometrial thickening accompanies. Inhibin B is normal in fibroma, elevated in GCT.
Distinguishing Feature
Thecoma is entirely solid, T2-hypointense, and may produce estrogen similar to GCT. However, cystic component ('sponge' pattern) is absent in thecoma. Thecomas generally have a benign course and are smaller than GCT. Definitive differentiation is made histopathologically.
Distinguishing Feature
Serous carcinoma is bilateral, with more aggressive enhancement, peritoneal carcinomatosis (omental cake, ascites), and CA-125 elevation. GCT is usually unilateral, peritoneal dissemination is rare, CA-125 is normal/mildly elevated; instead, inhibin B is elevated. Endometrial thickening accompanies GCT (typically absent in serous carcinoma).
Distinguishing Feature
Dysgerminoma is a solid homogeneous mass seen in young women (<30). Shows intermediate-high T2 signal (different from GCT). LDH is elevated (not inhibin B). Lobulated appearance with fibrous septa is typical. GCT's 'sponge' pattern and estrogen-related endometrial thickening are absent.
Urgency
routineManagement
surgicalBiopsy
Not NeededFollow-up
annualTreatment is surgical — unilateral salpingo-oophorectomy (in young patients desiring fertility preservation) or TAH-BSO (postmenopausal). No adjuvant therapy is usually needed in stage I; survival >90%. Platinum-based chemotherapy (BEP regimen) is added in advanced stages. IMPORTANT: Long-term follow-up is mandatory due to late recurrences (5-20 years later) — annual follow-up with inhibin B, AMH, USG for at least 10-20 years is recommended. Endometrial biopsy should be performed due to concurrent endometrial pathology (hyperplasia 25-50%, carcinoma 5-10%). When presenting with acute abdomen (hemorrhage, rupture), emergency surgery is required.
Granulosa cell tumor is a low-grade malignancy that can recur late (10-20 years later). Concurrent endometrial pathology should be screened due to estrogenic effects. Serum inhibin is used for follow-up. Prognosis is generally good (>90% 5-year survival in stage I).