Plasmacytoma : Small Bowel
Extramedullary plasmacytomas involving the small bowel are extremely rare. Some authors believe that plasmacytomas reported in this location might actually be marginal zone lymphomas with plasmacytic differentiation. This elderly male presented underwent surgery for small bowel obstruction. There was a 6.5 cm polypoid, ulcerated mass in the resected specimen. Sections showed a high-grade tumor with plasmacytic features. There were scattered areas of amyloid deposition in the stroma. The tumor cells were strongly positive for CD138 and kappa light chains. Lambda light chains were negative.