SYP and carcinoma: LCNEC and associated carcinoma have similar genomic profiles suggesting monoclonality in origin, and LCNEC has additional genetic abnormalities in comparison with associated carcinoma suggesting that dedifferentiation of associated carcinoma may cause LCNEC.2 Taube experienced a case of HGSC with metastasis of LCNEC component3 and analyzed 178 HGSC, and synaptophysin expression was found in 6.7% of cases suggesting neuroendocrine differentiation.