Silica granuloma of eyelid and ocular adnexa.

Seven cases of subcutaneous epithelioid granulomas caused by silica and involving the eyelids and periorbital region are described. Histologically, all cases disclosed epithelioid tubercles and varying numbers of foreign-body-type giant cells, areas of scarring, and birefringent crystals. Light microscopy with polarized readily facilitated visualization of the crystals. Scanning electron microscopy and energy dispersive x-ray analysis clearly established that the crystals were composed of silica in both its pure and combined forms. This study emphasizes the need for examination of all epithelioid granulomas with polarized light. If crystalline foreign bodies are identified, further special techniques should be used for chemical characterization of the crystals.