A 59-year-old woman, postmenopausal for eight years, G6P6 (six pregnancies, six full-term deliveries), with no history of miscarriage or ectopic pregnancy.

Personal history: No significant medical or surgical history prior to the surgery.

Family history: No similar cases reported in the family.

The patient presented with persistent pelvic pain for eight months. No other hormonal or gastrointestinal symptoms were reported. The ovarian mass was discovered during this evaluation, and the patient underwent surgery in the Gynecology Department of Hassan II University Hospital, Fez. She was subsequently referred to the Medical Oncology Department of the same institution for adjuvant treatment.

The patient underwent exploratory laparotomy with:

Perioperative findings: Right ovarian mass measuring 80 mm, highly vascularized and partially ruptured, with free tissue fragments in the pelvic cavity; left adnexa, liver, spleen, digestive tract, and paracolic gutters were normal; no peritoneal effusion observed.

FIGO classification: Stage IC2

Rationale: Tumor confined to one ovary, with capsular rupture prior to surgery, no regional lymph node metastases, and no distant metastases.

The patient received six cycles of adjuvant carboplatin-paclitaxel chemotherapy, initiated on April 7, 2024, and completed on June 26, 2024.

At the latest follow-up, the patient was in good general condition, under regular monitoring, with no evidence of local or metastatic recurrence.

A serum CA-125 tumor marker measurement was performed for the first time on September 25, 2024, three months after the last chemotherapy cycle on June 26, 2024, showing a value of 16.2 U/mL, within the normal range. A second assessment, conducted on May 22, 2025, demonstrated a stable and normal level. No other serum tumor markers were evaluated. This course is consistent with the typically non-secreting nature of pure Sertoli cell tumors.

Sertoli cell tumors are rare ovarian neoplasms that, together with Sertoli-Leydig cell tumors and Leydig cell tumors, account for less than 1% of all ovarian tumors [9] . In the largest series published by Oliva et al., including 54 cases, patients’ ages ranged from 2 to 76 years (mean 30 years). All tumors were unilateral, and the majority were diagnosed at an early stage (44 stage I cases: 42 IA and 2 IC) [3] .

Sertoli-Leydig cell tumors frequently secrete androgens, mainly testosterone, responsible for virilization, while estrogenic secretion is rare [10] . In contrast, Sertoli cell tumors are most often non-functional. When hormonal activity is present, it is mainly estrogenic, potentially causing menstrual irregularities, postmenopausal bleeding, or endometrial hyperplasia. Progesterone or testosterone secretion is exceptional and may lead to endometrial decidualization or signs of amenorrhea or virilization, respectively [7] .

In our case, the patient exhibited no clinical signs of hormonal secretion, confirming the non-functional nature of the tumor. However, histological examination revealed non-atypical endometrial hyperplasia, suggesting the presence of subclinical estrogenic secretion. Although clinically silent, this phenomenon may carry prognostic implications, particularly regarding endometrial surveillance. This observation highlights that the absence of overt hormonal symptoms does not entirely exclude a degree of hormonal activity within the tumor.

Macroscopically, these tumors usually appear as lobulated, solid masses, yellowish to brown in color. Immunohistochemically, EMA, inhibin, and chromogranin form the most useful triad of markers to exclude two common mimickers of Sertoli cell tumors: endometrioid carcinoma (inhibin−; EMA+; chromogranin−) and carcinoid tumor (inhibin−; EMA+; chromogranin+) [3] . Although CD99 and calretinin are often expressed in these tumors, they are less specific and less useful in differential diagnosis.

In our case, from a differential diagnostic standpoint, a gastrointestinal stromal tumor (GIST) was initially considered based on the preoperative imaging findings. However, histopathological and immunohistochemical analyses allowed this hypothesis to be ruled out. The absence of CD117 (c-KIT) and DOG1 expression, hallmark markers of GISTs [11] , together with the positive staining for calretinin and WT1, strongly supported the diagnosis of a sex cord-stromal tumor of the Sertoli cell type.

For sex cord-stromal tumors, FIGO stage IC2 after complete surgery justifies platinum-based adjuvant chemotherapy due to the increased risk of recurrence associated with capsular rupture.

According to NCCN guidelines, the preferred regimen for these patients is six cycles of carboplatin-paclitaxel. The BEP regimen (bleomycin, etoposide, cisplatin) is an alternative, particularly in younger patients or when carboplatin-paclitaxel is contraindicated. The EP regimen (etoposide-cisplatin) may be used if bleomycin is contraindicated [12] .

ESMO recommendations support this approach, emphasizing that adjuvant chemotherapy is indicated for high-risk stage IC tumors following complete surgery [13] .

In our case, the postmenopausal patient with a stage IC2 Sertoli cell tumor received six cycles of carboplatin-paclitaxel according to these guidelines, with good tolerance and favorable outcome.

Overall prognosis for sex cord-stromal tumors confined to the ovary remains favorable, but prolonged follow-up is recommended due to the rare but possible occurrence of late recurrences. Given this risk, long-term follow-up is recommended. According to ESMO, the median time to recurrence is 4 - 6 years, with cases reported up to 37 years after diagnosis. Follow-up visits should include a clinical examination and, if indicated, tumor marker assessment every 6 months from the third year onward, with this schedule maintained indefinitely. The NCCN recommends, for early-stage low-risk patients, follow-up visits every 6 - 12 months, and for high-risk stages, every 4 - 6 months during the first two years, with imaging performed only if symptomatic or in case of abnormal laboratory findings [12] [13] .

This case illustrates a Sertoli cell tumor occurring in a postmenopausal setting, an exceptionally rare event. Despite the presence of endometrial hyperplasia, the patient exhibited no clinical signs of hormonal secretion, confirming the clinically non-functional nature of the tumor. Recently, Kumar et al. (2025) [14] reported a similar case of a pure Sertoli cell tumor incidentally discovered in an atrophic ovary of a 70-year-old postmenopausal woman, underscoring the rarity and clinical relevance of such observations. These cases highlight the importance of a multidisciplinary diagnostic approach and management aligned with international guidelines, while contributing valuable insights to the limited literature on this uncommon entity.