Unusual silica granulomas of the skin with massive involvement of axillary lymph nodes

Silica granulomas are rare in the skin. Involvement of the regional lymph nodes seems to be unusual. The case of a 35-year-old man with massive diffuse fibrosis of the axilla with multiple foreign body granulomas and involvement of axillary lymph nodes is presented. The lymph nodes exhibit multiple epithelioid cell granulomas and silicotic nodules which are indistinguishable from similar nodules in mediastinal lymph nodes in pulmonary silicosis. It is assumed that the numerous silica particles which were identified by X-ray microanalysis under the scanning electron microscope and recovered from the mineral ash after incineration were accidentally implanted into the skin at the time of an injury 26 years previously. The long delay between silica exposure and granuloma development is a typical feature of these lesions. The possible mechanisms operative in this process are discussed.