CD99 and neuroendocrine neoplasm: For the concordant final cytopathological diagnosis of SPN, a combination of cytomorphological and immunohistochemical findings is widely recommended.26 To differentiate between neuroendocrine tumours, the recently proposed β-catenin, CD10, and PR were used, but not CD99, which is not specific for SPN.19,26 Instead, the CyclinD1, chromogranin and an additional, SOX11 were utilised (Table 1).