Ovarian strumal carcinoid - case report.

Strumal carcinoid represents a rare form of ovarian teratoma, consisting of both thyroid tissue and carcinoid structures. The carcinoid component is a well-differentiated neuroendocrine tumor with excellent prognosis. Strumal carcinoid tumors are commonly found in peri-menopausal women who are not usually interested in preserving their fertility and who are thus open to radical surgical treatment. In this report, we present a 24-year-old, nulliparous patient with strumal carcinoid, confirmed by histopathology and a large panel of immunohistochemistry (IHC) markers, who wished to preserve her fertility. In this case, a conservative surgical treatment (salpingo-oophorectomy) served to preserve vital and reproductive prognosis, and correct tumor classification was of extreme importance. The morphological examination of strumal carcinoid showed struma ovarii with a thyroid follicle-like structure [positive for thyroid transcription factor 1 (TTF1), thyroglobulin, CD56, cytokeratin (CK) 19, and negative for Hector Battifora and mesothelioma 1 (HBME1)], and a neuroendocrine cell component with a trabecular arrangement and island growth (positive for synaptophysin, chromogranin, CD56, and CK7 negative), which were interlocked and intimately associated. Papillary thyroid carcinoma of follicular type was ruled out by CD56 positivity and HBME1 negativity. Medullary thyroid carcinoma with strumal component was excluded by calcitonin negative staining. Solid rosette-like structures with negative glial fibrillary acidic protein (GFAP) staining ruled out a neuroectodermal component. A multilocular mucinous cystadenoma was identified without other teratoma components. Strumal carcinoid requires a meticulous examination to rule out other entities with malignant behavior and poor prognosis. In this case, a conservative treatment is sufficient to remove the tumor, preserving vital and reproductive prognosis.