Unusual virilization in girls with juvenile granulosa cell tumors of the ovary is related to intratumoral aromatase deficiency.

Background: Hyperandrogenism is a rare symptom of juvenile ovarian granulosa cell- tumors (JGCTO). This study aimed to determine whether hyperandrogenism was related to overexpression of SOX9, decreased expression of FOXL2 or absent aromatase expression in tumor with particular scheme of expression of P450scc and P450c17alpha.

Methods: Through a nationwide study including the French Society of Pediatric Oncology, 6/30 patients with JGCTO presented with clinical hyperandrogenism and high plasma testosterone. Tumor specimens underwent immunofluorescence (SOX9, FOXL2) and immunochemistry (aromatase, P450scc, P450c17alpha). Results were compared with patients without hyperandrogenism.

Results: SOX9 was expressed in the granulosa cell nucleus in 2/6 cases but also in 9/24 tumors without hyperandrogenism (p=n.s.). FOXL2 was absent or decreased in 3/6 cases of JGCTO with hyperandrogenism with no statistical difference from the group without this symptom. In 6/6 patients, the intratumoral expression of aromatase was absent (n=5) or dramatically reduced (n=1). In contrast, 15/24 patients without virilization exhibited conserved aromatase expression in their tumor (p<0.05). A variable number of tumoral cells expressed P450scc while some interstitial cells were focally immunopositive for P450c17alpha.

Conclusion: Unusual virilization in girls with JGCTO is not explained by a dysregulation in SOX9 or FOXL2 expression, but is related to a localized defect of aromatase expression in granulosa cells and to the ability of interstitial cells to produce testosterone.