Sex cord-stromal tumors are a rare type of ovarian tumor that account for up to 7–8% of ovarian neoplasms . Within these tumors, OSCT-NOS is a very rare subtype. SCT-NOS tends to affect young women, with a mean age of 43 years and occasionally before puberty . Most are benign, but 25–40% tend to have malignant activity, such as peritoneal metastasis, and they tend to be unilateral .
The term “steroid cell tumors” was first used by Scully in 1979, and previously they were classified as “lipid or lipoid” cell tumors. The term “not otherwise specified” implies that the cell lineage is not well defined and cannot be categorized as Leydig cell or stromal luteoma tumors [3, 5].
Its diagnosis is elusive and most of the time by exclusion. The most typical clinical manifestations of OSCT-NOS are androgen-related symptoms, such as hirsutism or virilization, present in 56–77% of cases due to most of its tumors are functioning. Furthermore, 5–6% are clinically associated with Cushing’s syndrome and 25% are non-functioning . However, in case of a woman complaining of hyperandrogenic symptoms, it is important to bear in mind the wide range of differential diagnoses, such as PCOS, non-classical congenital adrenal hyperplasia, ovarian or adrenal tumors, hyperthecosis, or androgen-secreting neoplasms . For this purpose, proper laboratory and imaging tests should be performed. In our case, we discarded those diagnoses due to normal DHEA and DHEAS levels, the lack of normalization of testosterone and 17-OHP levels after a suppression test with dexamethasone, the absence of polycystic ovarian morphology, and the presence of a right adnexal tumor in the ultrasonography and tomography scans. The observation that SCT had different echogenicity from the ovary and low impedance values could be useful for diagnosis ; however, some misdiagnoses could be reported if it has a multicystic structure .
The pathology characteristics of the OSCT are useful in confirming the diagnosis. Macroscopically, the SCT are often yellow due to their lipidic content, solid, and well circumscribed . The evaluation of histological characteristics is mandatory for proper classification. NOS tumors lack Reinke crystals in the cytoplasm, proper of Leydig cell tumors. Additionally, they have eosinophilic cytoplasm, irregular cords, nests of large rounded-to-polygonal cells, and round nuclei with prominent nucleoli [3, 8]. Their stroma is sparse, consisting of delicate connective tissue supporting rich vascularity .
There are certain pathological features that indicate malignancy: two or more mitotic figures per ten high-power fields (associated with 92% of malignancy), tissular necrosis (86% of malignancy), a diameter bigger than 7 cm (78% of malignancy), hemorrhage (77% of malignancy), and nuclear atypia grade 2 or 3 (64% of malignancy) [5, 9]. In the present case, we did not find any of the characteristics mentioned above, leading us to classify it as a benign tumor. Furthermore, besides histology, in this case the immunohistochemistry revealed that tumoral cells were positive for vimentin and gonadotropin chorionic hormone and negative for estrogen receptors, progesterone receptors, and androgen receptors, confirming the diagnosis.
The primary treatment of OSCT-NOS is surgery. Other treatments, such as radiotherapy or chemotherapy, have not been tried, probably due to OSCT-NOS being rare and most often benign. There are some reports that suggest the use of gonadotropin-releasing hormone analogs (GnRHa) to decrease hormonal secretion and induce apoptosis as an attempt to avoid surgery or as a postoperative adjuvant therapy. However, the most recommended approach in young women with low-stage disease, as presented in this case, is a unilateral salpingo-oophorectomy. This surgery also allows for the preservation of fertility [3,4,5, 8]. However, if there is evidence of malignancy, an additional hysterectomy should be performed . Most cases reported in the literature, as in this case, normalize their menstrual cycles and virilization signs along with testosterone, androstenedione, and 17-OHP levels after surgery.