Endocrine Abstracts

Introduction: Gastric endocrine tumors (GET) are rare. Type 1 tumors are non-functioning, almost exclusively benign lesions, usually presenting as multiple polyps, usually <1 cm in diameter, which arise from gastric enterochromaffin-like cells in response to chronically elevated gastrin, secondary to (auto-immune) atrophic fundic gastritis. These tumors were traditionally treated with total gastrectomy, like adenocarcinomas. Currently, surveillance or endoscopic treatment is recommended, as surgery is reserved for cases of malignant development or recurrence. More recently, some reports showed encouraging results of medical therapy with somatostatin analogues (SA).

Case report: A 58-year-old female, without relevant medical or family medical history, presented with dyspepsia. Upper gastrointestinal endoscopy (UGIE) was performed, revealing multiple polyps <1 cm. Histology showed well-differentiated endocrine tumour (WDET) with extension to muscularis mucosa, atrophic gastritis and Ki67=2–20%. Gastrin levels were increased 9-fold (828 pg/ml; nr<90). Admitted to our hospital, UGIE was repeated, revealing WDET with Ki67<2%. Chromogranin A (CgA) was elevated (342 ng/ml; nr<134); anti-parietal cell antibodies were positive and anti-intrinsic factor were negative. After considering all therapeutic options, it was decided to start therapy with SA (20 mg, every 28 days). Six months later, UGIE showed reduction of polyps number and diameter and biopsy samples revealed absence of GET; gastrin decreased to 233 pg/ml. After 12 months, UGIE revealed disappearance of the tumors, CgA levels normalized and gastrin decreased to 124 pg/ml.

Discussion: We describe a case of a multiple type 1 GET <10 mm of diameter, with a Ki67=2–20%. Medical therapy with SA resulted in regression of these tumors, normalization of CgA levels and almost normalization of gastrin, supporting the described antiproliferative effect of this treatment. SA may be a good alternative therapeutic approach for type 1 GET, although the duration of the therapy is still to be determined, based on cost-benefit studies.