Cytomorphologic diagnosis of adult granulosa cell tumors at the metastatic sites with an emphasis on the cytologic mimics

Am J Transl Res. 2023 Sep 15;15(9):5633-5641. eCollection 2023.

Abstract

Introduction: Adult granulosa cell tumor (AGCT) is a rare ovarian sex-cord malignancy notorious for late recurrences and metastases. The cytologic features of AGCT at the metastatic sites have been documented sporadically. Hence, knowledge of the characteristic cytomorphologic features is essential for an accurate diagnosis and distinguishing it from its pathologic mimics, especially at the metastatic sites.

Materials and methods: This was a retrospective study conducted over six years. The cytopathology electronic database was searched for the fine needle aspirates (FNA) reported as metastatic AGCT. A detailed cytomorphologic assessment was done for multiple cytologic features, including overall cellularity, cellular arrangement of the tumor cells, cell size, cell shape, nuclear pleomorphism, nuclear grooving, chromatin pattern, nucleolar prominence, mitotic figures, amount and character of cytoplasm, and the extracellular background.

Results: There were 6 cases reported as metastatic AGCT on aspiration cytology. The smears in all the cases were cellular, with tumor cells arranged in loose aggregates, three-dimensional clusters, perivascular papillary fronds, and scattered singly. The most consistent cytologic features included microfollicular arrangement of monomorphic tumor cells with round-oval nuclei, fine chromatin, longitudinal nuclear grooving, and scant cytoplasm. Typical Call-Exner bodies and metachromatically stained extracellular hyaline material were noted sporadically. None of the smears showed anaplasia, prominent macronucleoli, atypical mitoses, or necrosis.

Conclusions: The current study not only outlines the distinct cytologic attributes of AGCTs across various metastatic locations but also highlights its prevalent cytologic mimics. Additionally, it outlines key clinicopathologic traits that can aid in distinguishing and precisely diagnosing these tumors through cytological analysis.

Keywords: Granulosa cell tumor; adult granulosa cell tumor; cytology; fine needle aspiration cytology; immunocytochemistry; metastatic AGCT.