Abstract
Extramedullary plasmacytomas are uncommon tumors that affect various tissues, most commonly in the upper airways. We report a case of solitary plasmacytoma of the lung that was difficult to differentiate histopathologically from Castleman's lymphoma.
A 55-year old woman was admitted to our hospital with an abnormal shadow on chest X-ray films but no symptoms. Chest CT scan disclosed a solitary nodule with low density in the right upper lobe. Right upper lobectomy was performed, and histological examination showed diffuse proliferation of plasma cells and lymphoid follicles partially similar to Castleman's lymphoma. Immunohistologically, the plasmacytoma cells were stained with IgA and λ chains in a monoclonal secretory pattern.
