Ovarian Sex Cord Stromal Tumor With Annular Tubules: A Rare Diagnosis in Young Women.

Ovarian sex cord-stromal tumor with annular tubules (SCTAT) is a rare neoplasm with distinct clinicopathological features in its sporadic and syndromic forms, the latter commonly associated with Peutz-Jeghers syndrome. Although imaging may suggest a sex cord-stromal origin, definitive diagnosis relies on histopathological examination. SCTAT primarily affects young women, and fertility-sparing surgery is typically preferred, often producing favorable outcomes. Nevertheless, the risk of recurrence remains significant, necessitating long-term follow-up. We report the case of an asymptomatic 36-year-old woman whose routine pelvic ultrasound detected a unilateral, solid, and vascularized right adnexal mass. Further imaging strongly suggested a stromal tumor, which was confirmed as SCTAT by histology after fertility-sparing laparoscopic salpingo-oophorectomy. No adjuvant treatment was given, and genetic testing ruled out Peutz-Jeghers syndrome. At six months postoperatively, there was no evidence of recurrence or tumor marker elevation. This case, the second reported SCTAT in Portugal, highlights the importance of multidisciplinary management and vigilant surveillance for optimal patient care.