Eggshell calcification of lymph nodes: an update.

Peripheral calcification of lymph nodes, "eggshell calcification," commonly occurs in patients with silicosis and coal-worker's pneumoconiosis. Sarcoidosis, postirradiation Hodgkin disease, blastomycosis, and scleroderma are other reported causes. Two not previously described causes, amyloidosis and histoplasmosis, are presented, and disorders that simulate eggshell calcification are listed. The explanation for the eggshell pattern of calcification is not known.