Sex Cord Tumor with Annular Tubules (SCTAT): A Rare Variant of Granulosa Cell Tumors? FOXL2 and SOX9 Distinguish the Lineage of the Sex Cord Derivatives.
Rebecca Buell-Gutbrod, Marina Ivanovic, Anthony Montag, Jamie Steinmetz, Katja Gwin. University of Chicago, IL
Background: Sex cord tumor with annular tubules (SCTAT) is a rare tumor occurring both sporadically and in association with Peutz-Jeghers syndrome. Morphologically it is composed of simple and complex annular tubules with peripherally oriented nuclei surrounding central hyaline bodies of basement membrane material. The sex cord cells have been described variably as Sertoli or granulosa cells or as “with morphologic features intermediate between those of the granulosa and Sertoli cell tumor”. Ultrastructural studies have revealed variable results. FOXL2 is a member of the forkhead-winged-helix family of transcription factors and is expressed early in the female gonad. It is required for differentiation of granulosa cells during folliculogenesis. The transcription factor SOX9 is an autosomal downstream target of SRY and is required for formation of Sertoli cells. The aim of our study was to characterize the differentiation of the sex cord cells in SCTAT by evaluating the expression of these two counteracting transcription factors.
Design: Archival paraffin embedded material of 2 SCTATs were examined by IHC for expression and localization of FOXL2 and SOX9. Both cases were unilateral tumors and occurred in adult females (43 and 49 years of age). There were no stigmata of Peutz-Jeghers syndrome in either of the patients and both cases were thus considered sporadic.
Results: The sex cord cells revealed strong nuclear staining for FOXL2 in 2/2 cases and were negative for SOX9 expression.
Conclusions: SCTAT is a rare sex-cord derived tumor made up of cells variably described as Sertoli or granulosa like. Expression of FOXL2, which is found in granulosa cells and actively suppresses the Sertoli associated SOX9 throughout adult life via an upstream regulatory element, supports a granulosa cell origin for these cells. These findings suggest that sporadic SCTAT may be best classified as a variant of granulosa cell tumor.
Category: Gynecologic & Obstetrics
Tuesday, March 1, 2011 1:00 PM
Poster Session IV # 125, Tuesday Afternoon