Case Report of Insular Carcinoid Arising From Mature Cystic Teratoma

Primary ovarian Neuroendocrine Tumors (NETs) develop in pure form or in association with other tumors, mainly teratomas. Teratomas are the most common type of ovarian germ cell tumor. They are divided into three categories: mature (cystic or solid, benign), immature (malignant), and monodermal or highly specialized. Most teratomas are cystic and composed of mature adult-type tissues; they are better known as dermoid cysts. The Mature Cystic Teratoma (MCT) accounts for more than 95 percent of all ovarian teratomas and is almost invariably benign [1]. Mature cystic teratomas contain mature tissue of ectodermal (e.g, skin, hair follicles, sebaceous glands), mesodermal, and endodermal origin [2]. They are bilateral in 10 to 17 percent of cases [4]. Malignant transformation occurs in 0.2 to 2 percent of mature cystic teratomas [5-7]. Mature teratomas with malignant transformation comprise 2.9 percent of all malignant OGCTs [8]. The most common malignant change in a dermoid cyst is squamous cell carcinoma, followed by adenocarcinoma and carcinoid tumor [9-11]. The prevalence of Primary Ovarian Carcinoids (POC) is merely 0.1% in ovarian neoplasms and 1% in carcinoid tumors. POC was classified into trabecular, strumal, mucinous, and insular types, among which the latter is the most prevalent type and the only 1 associated with Carcinoid Syndrome (CS.) We report an extremely rare case of insular carcinoid tumor arising from a mature cystic teratoma with typical clinical manifestation.