A Rare Cause of Gastric Ulcer

Abstract

An 84-year-old man was admitted to our hospital with melena. He was on aspirin, ibuprofen and warfarin. He had history of atrial fibrillation and ischemic cardiomyopathy. He was on no GI prophylaxis. After appropriate resuscitation and PPI therapy, an EGD was performed. 4 clean based gastric ulcers were found (30 mm in the body, 5 mm in the antrum and two 15 mm in the fundus). Because the patient's INR was 1.6, biopsies were not obtained. H. pylori IgG was found positive.EGD was repeated in 3 days. The ulcers were identified again. Multiple biopsies were obtained to rule out neoplasia. Histopathology showed gastric mucosa with severe acute/chronic inflammation of the lamina propria with slight gland distortion. The patient was discharged home on PPI. Therapy for H. pylori was also started. Five weeks later, another EGD was performed in order to evaluate healing. The ulcers in the antrum and fundus have healed. The large ulcer of the gastric body was almost unchanged. Multiple biopsies were obtained. The mucosa was extensively infiltrated by an abnormal plasma cell population. The cells had rounded nuclei, distinct nucleoli, partially clumped chromatin, and abundant eccentrically distributed cytoplasm. They were not associated with a substantial abnormal lymphocyte population, and the morphologic features typically associated with a MALT lymphoma were not observed. The abnormal plasma cells expressed IRF4 (MUM1), and they had a monotypic staining pattern for lambda light chains. They were negative for the other markers for which they were tested. No H. pylor organisms were present. The abnormal plasma cells were negati EBV. The morphologic and phenotypic features indicated the diagnosis of a lambda light chain-restricted plasma cell neoplasm involving the stomach. The differential diagnosis rested between a solitary plasmacytic neoplasm of the stomach and unusual presentation of multiple myeloma.Hem-Onc was consulted. Bone survey did not reveal changes consistent with MM or plasmacytoma. Peripheral morphology showed normocytic anemia. Lambda and Kappa chains were elevated. PET-CT showed abnormal uptake in the distal stomach. Bone marrow biopsy was unremarkable. Chemotherapy was started with CyBorD with bortezomib, cyclophosphamide omitted and dexamethasone. After 3 cycles of chemotherapy, gastric biopsies showed only few reactive plasma cells. Primary extramedullary plasmacytomas account for approximately 4% of all plasma cell neoplasms. Gastric plasmacytoma is rare and constitutes in turn less than 5% of these tumors. Accordingly, the literature about this entity consists of anecdotal reports or small case series. This entity is usually localized and frequently pursues an indolent clinical course, but has a tendency for local recurrence and may rarely progress to MM. Its link with H. pylori infection is unclear.