Hyphalike pseudofungus in a lymph node.

Mediastinoscopic biopsy specimens of multiple paratracheal lymph nodes in a 66-year-old man with a history of resected pulmonary carcinoma were submitted for histologic evaluation. Structures present in one of these lymph nodes superficially resembled branching septate fungal hyphae. Perls' stain demonstrated that these structures contained iron, and Gomori's methenamine silver stain was negative. The histopathologic features are similar to those of the first and only previous case report of such structures.