Multiple myeloma involving the stomach with vitamin B-12 deficiency

Involvement of the gastrointestinal tract by plasmocytoma is rare. in a 78- year-old man with IgA lambda multiple myeloma stage IIIB, the evaluation of a megaloblastic anaemia revealed a subnormal vitamin B-12 level, Urinary e xcretion of isotope-labelled vitamin B-12 was reduced. Tests for gastric pa rietal cell and intrinsic factor antibodies were negative, There were no cl inical signs of an insufficient absorption in the ileum, Biopsy specimens o f the stomach showed a dense, diffuse infiltrate of malignant plasma cells in the lamina propria of fundus and corpus. A urease test for Helicobacter pylori was positive. There was a minor haematological improvement when vita min B-12 was given parenterally. Several combinations of cytostatic drugs h ad no effect on the manifestations of the multiple myeloma. In our patient the vitamin B-12 deficiency may be related to a displacement or destruction of parietal cells by malignant plasma cells. (C) 1999 Lippincott Williams & Wilkins.