Primary or secondary? Genotyping confirmation of an ovarian primary carcinoid tumor

Ovarian primary carcinoid tumors of pure histological type can pose a significant diagnostic challenge in its separation from metastatic carcinoids from the gastrointestinal tract. Yet, their clinical management and prognosis are drastically different. At the molecular level, ovarian primary carcinoid tumors are thought to be of germ cell origin, frequently after the first meiotic division. We report a 21.5-cm ovarian insular carcinoid tumor in a 50-year-old woman who had no evidence of extraovarian tumor. The absence of teratomatous components and the presence of lymphovascular invasion prompted additional studies to rule out a metastatic tumor. The nature of this primary ovarian tumor was eventually confirmed by demonstration of its germ cell origin through DNA genotyping.