An adequate biopsy that includes the subcutaneous tissue is very helpful in the evaluation of patients with suspected connective tissue disease. However, the histologic features must often be correlated with the clinical features and other laboratory tests for a definitive diagnosis. An objective histologic diagnosis can usually be made in scleroderma, lupus erythematosus panniculitis, amyloidosis, and angioedema, and in diseases such as lepromatous leprosy and mycosis fungoids (which are sometimes confused with connective tissue diseases). Correlation with clinical features and, sometimes, other laboratory tests is often required to establish a diagnosis of scleredema, dermatomyositis, myxedema, and lichen myxedematosus. The features in cheilitis granulomatosa usually are not specific, but a biopsy is helpful to rule out other diseases.