An Update in Histopathology and Immunohistochemistry of Ovarian Sex Cord-Stromal Camel Tumors

Abstract

Background: Sex cord-stromal tumors of the ovary are a rare and heterogeneous group of benign and malignant neoplasms with a wide range of histological characteristics. The current study investigated ovarian sex cord-stromal tumors in dromedary camels slaughtered at Egyptian slaughterhouses between January 2019 and February 2022. The study included 180 female single-humped camels in which all data on the animal's age, location, and gross tumor lesions were documented, and positive ovaries were collected for further histological and immunohistochemical examination.Results: Interestingly, our results diagnosed 15 cases of sex cord-stromal tumors (8.30 %) in the ovary of dromedary camels included; adult granulosa cell tumor (0.55 %), interstitial cell tumor (0.55 %), thecoma or fibrothecoma (1.10 %), steroid cell tumor-NOS (0.55 %), and granulosa-theca cell tumor (5.55 %). Specifically, all cases had distinctive histomorphological appearance characteristics for benign tumors, except adult granulosa cell tumor, which had sarcomatous changes and other features reliable for malignancy. Importantly, granulosa-theca cell tumor exhibited a wide spectrum of histologic patterns as micro/macrofollicular, trabecular, diffuse sheets and Call-Exner bodies; or uncommon patterns as solid follicular, luteinized, insular, tubule-like, and Sertoli-like. Immunohistochemically, the results indicated that vimentin was markedly expressed in the majority of sex cord-stromal tumors (SCSTs), and melan A was typically positive in the steroid-secreting tumors; while inhibin was less sensitive than vimentin for recognizing SCSTs. Conclusions: Diagnosis of sex cord-stromal tumors in camels often present a challenge familiarity with characteristics of the different histopathologic pattern where, in the current study, the granulosa-theca cell tumor was the most frequently diagnosed tumor. Additionally, the use of vimentin and melan A are reliable markers in the differential diagnosis of sex cord-stromal tumors in the ovary of dromedary camels.