Pathogenic ATM Variant-Harbouring Well-Differentiated Aggressive Type 1 Gastric Neuroendocrine Tumour with High-grade Features (G3 NET): a New Addition to the Clinical and Pathological Spectrum of Gastric Neuroendocrine Neoplasms

We report here a patient with an aggressive well-differentiated high-grade gastric neuroendocrine tumour (gastric grade 3 NET), in a context of autoimmune gastritis. Consistent with grade 3 disease, the tumour had a Ki-67 proliferation index of 30%. Targeted next-generation sequencing identified variants of four genes, including a pathogenicATM variant underlying the differentiation and metastatic potential of the tumour. Liver metastasis was diagnosed during follow-up, and the patient died after 6 years, due to disease progression.
Source: Endocrine Pathology - Category: Pathology Source Type: research