Neuroendocrine neoplasms (NENs) are broadly classified according to their morphological differentiation and proliferative rate in well-differentiated neuroendocrine tumours (WdNETs) (grade (G)1–2 (Ki-67 < 20%) or G3 (Ki-67 ≥ 20%, usually ≤50%)) and in poorly differentiated neuroendocrine carcinomas (PdNECs) (always G3, Ki-67 ≥ 20%) [1]. Here, MKI67 is linked to neuroendocrine neoplasm.