Neuroendocrine carcinomas (NECs) are a rare, high-grade, poorly differentiated (PD) form of neuroendocrine neoplasms (NENs).1 The annual incidence of PD extrapulmonary (EP) NEC is approximately one diagnosis per 100 000 persons.2 3 These tumours are characterised by aggressive histological features; high Ki-67 index (>20% by definition, but usually higher (>75%)),4 extensive necrosis and nuclear atypia, and are classified as NEC grade 3 according to WHO 2010 classification.5 Here, MKI67 is linked to neoplasm.