Helicobacter pylori-Negative Gastric Mucosa-Associated Lymphoid Tissue Lymphoma Presenting with Melena as the Initial Symptom

Abstract

A male in his 70s noticed appetite loss and experienced transient loss of consciousness while standing up from a sitting position. On the evening of the same day, he developed black stools and came to our hospital.

Upper gastrointestinal endoscopy revealed multiple ulcers in the stomach. Pathological examination of biopsy specimens of an ulcer revealed infiltration of atypical lymphocytes and lymphoepithelial lesions. In addition, he was diagnosed with mucosa-associated lymphoid tissue (MALT) lymphoma by immunostaining. The patient was negative for Helicobacter pylori antibodies in sera and H. pylori antigens in stool specimens. Moreover, combined positron emission tomography and computed tomography (PET-CT) imaging showed no nodular lesions. Clinical remission has been maintained by radiotherapy (32 Gy in 20 fractions).

Although rare, MALT lymphoma may cause hematemesis and/or melena.