[Primary carcinoid of ovary: a clinicopathologic analysis of 17 cases]

Objective: To study the clinicopathologic feature, diagnostic strategy and prognostic significance of primary carcinoid of the ovary (PCOTO). Methods: A series of 17 patients previously diagnosed as PCOTO at Department of Pathology, Peking Union Medical College Hospital during the period from 2002 to 2017 were evaluated with clinical data analysis, histopathology and immunohistochemistry, and the patients were followed up and the relevant literatures were reviewed. Results: The age of patients ranged from 24 to 64 years (mean, 42 years). Fourteen patients were found a pelvic mass for a health check-up, and only 3 patients presented with pain in the lower abdomen. The left ovary was involved initially in ten patients, and the right in seven. The major axis of the tumor ranged from 2 to 14 cm. The surface of these tumors was smooth. Seven of the tumors were solid-cystic, 6 were cystic and 4 were solid. Under light microscope, 6 cases were diagnosed as strumal carcinoid, 4 cases were insular carcinoid, 4 cases were trabecular carcinoid, 3 cases were insular and trabecular mixed type carcinoid and 1 case was mucinous carcinoid. The mitotic figures were no more than 1/10 HPF.There were 11 cases complicated with other ovarian tumors, including 10 cases with teratoma, and 1 case with mucinous cystic adenoma. The paraffin-embedded tissues of all cases showed immunoreactivity for NSE and Syn, and the positive propotion of CgA was 10/17. TTF1 was positive in thyroid follicles and negative in strumal carcinoid. The positive index of Ki-67 was no more than 2%. Follow-up of 13 to 188 months showed 16 patients without recurrence and 1 patients were loss to follow-up. Conclusions: PCOTO is very rare. Most of the patients are found with a mass during health check-up in unilateral ovary and without obvious clinical symptoms. Histologically, the tumor always exists with other ovarian tumors, including teratoma and mucinous cystic adenoma, with relatively good prognosis.