Cutaneous sarcoidosis: Definitions and types of lesions

Abstract

Sarcoidosis is a peculiar granulomatous disease of unknown etiology. Most commonly, it involves the lungs, lymph nodes, liver, spleen, skin, eyes, phalangeal bones, and parotid glands, but other organs may be involved. The pathology consistently shows nonca-seating granulomas with a lack of surrounding lymphocytes (naked tubercules) in all of the involved tissues. There are no consistent laboratory findings, although many patients show a depression in some aspects of cell-mediated immunity. The serum angiotensin-converting enzyme may be elevated, as may the sedimentation rate, but none of these tests is diagnostic. Diagnosis rests with the characteristic pathology, the finding of disease in more than one organ, and the elimination of other etiologic possibilities. Noncaseating granulomas limited to skin lesions, in the absence of findings in other organs, cannot be labeled as sarcoidosis; they are sometimes referred to as sarcoidal reactions.