Primary ovarian trabecular carcinoid tumor: a case report and literature review

Introduction Carcinoid tumors are uncommon neoplasms in the diffuse peripheral endocrine system. Ovarian carcinoids are rare and can be primary or transplanted. Primary ovarian carcinoids make up approximately 0.5-1.7% of all carcinoid tumors. Case report We describe the case of a 55-year-old female patient. A tumor in her right ovary was discovered during a regular examination. She had no significant clinical symptoms, but a pelvic ultrasound revealed a solid mass measuring 6.2 x 5.2 x 3.5 cm located in the right ovarian lobe. Serum AFP, CA199, CA125 and CEA levels were all within normal limits, as were serum E2, FSH and Prog hormone levels. The patient underwent a total hysterectomy and bilateral salpingo-oophorectomy. The right ovary and tumor were separated into two parts by the gynecologist. They were 4.0 x 3.1 x 2.5 cm and 3.2 x 2.0 x 1.1 cm in size, respectively. The tumor was totally solid and had a yellowish color and a smooth surface. There were no teratomatous components seen in the mass. Multiple sections showed that the tumor was a total epithelial neoplasia with a trabecular structure surrounded by dense connective tissue. The tumor cells had abundant granular cytoplasms. Silver staining showed neuroendocrine granules, and reticulin staining showed that tumor cells were arranged in a trabecular structure. The immunohistochemical study revealed a neuroendocrine origin with strong positivity for NSE, CgA and Syn. Other markers, such as a-inhibin and Calretinin, were negtive. Finally, the case was diagnosed as a primary ovarian trabecular carcinoid tumor. Conclusion Primary ovarian trabecular carcinoid tumors are very rare. The patients lack clinical indicators, and final diagnosis depends on pathological examination, special staining and inmmunohistochemistry staining to confirm the neuroendocrine differentiation.