Idiopathic fibrosclerosis.

Idiopathic fibrosclerosis (IF) is an acute and chronic inflammatory cellular infiltration of tissue associated with varying amounts of fibrosis. Clinical prototypes of IF include retroperitoneal fibrosis, mediastinal fibrosis and Reidel's struma of the thyroid. IF has been associated with numerous other diseases in the literature including systemic lupus erythematosus, scleroderma, polyarteritis nodosa and reactions to several drugs, especially, methysergide and several antihypertensive. However, no clear etiologic factor for either the inflammatory component or the fibrosis has been found. We present 2 cases of IF that exemplify the protean nature of the disease and its potential response to immunosuppressive therapy.