Granulosa cell tumors of the ovary with a pseudopapillary pattern: a study of 14 cases of an unusual morphologic variant emphasizing their distinction from transitional cell neoplasms and other papillary ovarian tumors

Granulosa cell tumors of the ovary with a pseudopapillary pattern have received only passing mention in the literature. We have reviewed the clinicopathologic features of 10 cases of juvenile granulosa cell tumor and 4 cases of adult granulosa cell tumor with a pseudopapillary pattern. Twelve cases were received in consultation; the referring pathologist favored a diagnosis of a transitional cell neoplasm in 3 of these cases, and a retiform Sertoli-Leydig cell tumor in 2 cases; in most of the remainder, the diagnosis of granulosa cell tumor was considered but uncertainty expressed because of the unusual papillarylike pattern. All 14 tumors were unilateral, and the majority were predominantly cystic, 3 unilocular, and 6 multilocular. Multiple papillary projections lining the cyst wall were noted grossly in 10 cases; these ranged in size from 0.1 to 1.5 cm and were typically soft, edematous, fleshy, or rubbery. Microscopically, pseudopapillae were formed by intracystic cellular projections with surrounding necrotic debris and/or undulating folds of neoplastic cells in the absence of appreciable necrosis. In all tumors, thorough sampling revealed areas with architectural patterns and cytomorphology typical of granulosa cell tumor. Granulosa cell tumors of adult and juvenile type may have a pseudopapillary pattern that can be confused with other ovarian tumors with a papillary architecture. Identification of areas that are more characteristic of granulosa cell tumor resolves most cases, although immunohistochemistry can be used in more problematic tumors. This phenomenon seems to be related to the cystic change that is a feature of many granulosa cell tumors.