Gastric submucosal haematoma caused by an amyloidoma in the setting of multiple myeloma

This is a case of a 67-year-old woman with a history of multiple myeloma with amyloidosis who presented with massive hematemesis. Emergent upper endoscopy revealed a mass on the greater curvature of the stomach, which measured approximately 3 cm in width and 7 cm in length. The patient underwent a wedge resection of the gastric mass without complication. Microscopic examination of the gastric mass revealed amorphous deposits that were congophilic in nature and stained positive with Alcian blue. These findings are consistent with amyloidosis. The patient had a favourable postoperative recovery and was discharged from the hospital. This case highlights the need for clinicians to be aware of the possibility of spontaneous gastric haemorrhage secondary to light chain (AL) amyloidosis, especially in patients with a known bone marrow disorder.