Ovarian Leydig cell tumor (hilus cell tumor): A case report

Abstract

Objective: Leydig cell tumor is a rare ovarian tumor that belongs to the group of sex-cord stromal tumors. They produce testosterone leading to hyperandrogenism. As a subtype of steroid cell tumors of the ovary characterized by the presence of Reinke crystals, it comprises 19% and affects mainly young women. Material and Methods: A 24-year old nulliparous patient clinically presented with hirsutism, oligomenorrhea, and infertility. Ultrasonography showed a left ovarian tumor mass with the greatest diameter of 4.3 cm. The patient underwent a laparoscopic tumorectomy followed by gradual withdrawal of the symptoms at the first check-up after 6 months follow-up. Results: The laparoscopically obtained material consisted of 15 yellow to orange-tanned, soft and solid fragments with a diameter ranging from 0.5 to 5.5cm. Microscopically, the tumor was solid, relatively well-circumscribed, and composed of cellular areas with clustering of nuclei separated by eosinophilic anuclear zones. Some of the tumor cells had scant and others abundant eosinophilic or clear cytoplasm with lipid-rich, oil Red O-positive vacuoles and oval, hyperchromatic or bizarre nuclei. Mitotic figures were scarce, while Reinke crystals were found after a prolonged search. Immunohistochemically, tumor cells showed diffuse positivity for vimentin, focal for cytokeratin AE1/AE3, alfa-smooth muscle actin, S100, CD99, calretinin, inhibin-alpha, melan A, CD56 and were steroid hormone receptor negative. Conclusions: Although idiopathic hirsutism and other benign androgen excess disorders like polycystic ovarian syndrome are common, the presence of an ovarian mass in younger patients should raise suspicion of Leydig cell tumor or other steroid cell tumors. This case confirms that Reinke crystal quest should always be tenacious.