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.