Background: Extramedullary plasmacytoma is an uncommon entity that most commonly involves nasopharynx or upper respiratory tract. Involvement of the gastrointestinal tract occurs in approximated 10% of cases. Isolated primary plasmacytoma of colon is rare and only 7 well documented cases have been reported in the literature.

Methods: We present a case of 42 year male who presented with diarrhea. Multiple colonic strictures were found on investigation. Colonoscopic biopsy was not helpful in making any specific diagnosis. Patient underwent subtotal colectomy. Isolated primary colonic plasmacytoma was found on histopathological examination.

Conclusions: Plasmacytoma is known to occur in extra osseous sites. Primary colonic plasmacytoma, however, is a rare clinical entity. Primary colonic plasmacytoma may have varying clinical presentations including multiple colonic strictures that may mimic colonic tuberculosis or inflammatory bowel disease. Although these cases are rare, treating physician as well as radiologist, and pathologist should be aware of this entity.