CTNNB1 and neuroendocrine neoplasm: In contrast, pseudoinclusions represents herniation of the cytoplasm in the nucleus, which is typically for papillary thyroid carcinoma and meningioma and was also described as a feature for neuroendocrine tumours of the lung, in the latter partly as beta-Catenin accumulation due to a mutation in the CTNNB1 gene28,29.