Secondary extramedullary plasmacytoma causing small bowel intussusception in a patient with multiple myeloma - A case report.

Background: Multiple myeloma is a monoclonal, immunoproliferative plasma-cell neoplasm of the B lymphoid cells. Extramedullary plasmacytoma is a type of plasma-cell neoplasm that can present as a primary tumour or secondary to another plasma-cell neoplasm, such as multiple myeloma. Secondary extramedullary plasmacytoma is usually noted in the advanced stages of the disease with ileum involvement being very rare.

Methods: We report a rare case of a 58-year-old man, with known multiple myeloma, re-presenting with evidence of small bowel obstruction, secondary to an intussusception due to a malignant plasma cell deposit, which was successfully resected at laparotomy. Previous two similar admissions, prior to this index admission, failed to arrive at this difficult rare diagnosis.

Conclusions: Primary and secondary extramedullary plasmacytoma mainly affects the upper aero-digestive tract. Involvement of the ileum, as in this case, is a rare complication. Prognosis of secondary extramedullary plasmacytoma affecting the gastrointestinal tracts is unknown, due to the small number of cases reported in the literature, but suggestive of a poor prognosis. The role of surgery is often palliative to deal with resolvable life-threatening emergencies and where possible to prolong life. Conclusions: The case adds to the current literature of the rare event of visceral secondary extramedullary plasmacytoma involving the gastrointestinal tract, in the course of multiple myeloma and highlights the need for a high index of suspicion for such uncommon complications, to avoid delay in diagnosis and treatment.