The diagnosis of NECB requires the expression of neuroendocrine markers (chromogranin, synaptophysin, NSE) and the lack of simultaneous neuroendocrine carcinoma in extramammary sites.
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.
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.