The diagnosis of NECB requires the expression of neuroendocrine markers (chromogranin, synaptophysin, NSE) and the lack of simultaneous neuroendocrine carcinoma in extramammary sites.
The immunohistochemical profile showed positive staining for keratins, synaptophysin and chromogranin but negative for LCA, CDX2, CK7, CK20, TTF-1 and PSA, supporting the NEC diagnosis.
We report a case of an 19-yr-old female with bilateral ovarian teratomas with a high-grade NEC (immunohistochemically positive with chromogranin, synaptophysin, and CD56 and MIB1 proliferation index in excess of 90%) arising within one of these.