Palisading granulomas associated with lung cancer.

A granulomatous response to neoplastic structures was found in three cases of resected small-cell anaplastic carcinoma of the lung. This consisted of almost continuous rims of palisading epithelioid cells surrounding viable, necrotizing, and necrotic tumor nests. None of the patients had received chemotherapy or radiation treatment prior to surgery, and no clinical, microbiological, or histological evidence of tuberculosis, fungal infection, or rheumatoid disease was found. The granulomatous rim seems to be a response to spontaneous tumor decay.