Abstract

Systemic sclerosis (SS) is a connective tissue disorder characterized by diffuse fibrosis of the skin and internal organs. Skin findings are an early manifestation; other organs such as the lungs are typically involved later. The diagnosis of SS is based primarily on characteristic clinical findings and is supported by specific serologic abnormalities. Lack of clinical findings at the time of the presentation may lead to a delay in diagnosis and treatment. Skin biopsy can be very helpful in the early diagnosis of SS; however, histopathologic findings can be different from more common, well established disease. We report a 60 year old Caucasian female who presented with edematous, stiff skin for several months. On physical examination she had diffuse tightening of her skin throughout the body. A punch biopsy from right dorsal wrist was performed revealing a deep perivascular and interstitial lymphocytic infiltrate, thickening of reticular dermal collagen, eccrine gland atrophy, loss of periadnexal adipose tissue and replacement of subcutis by myofibroblasts and hyalinized connective tissue. Immunohistochemical staining with smooth muscle actin (SMA) confirmed the presence of myofibroblasts, whereas CD34 was diminished in the deep dermis. An elastic stain showed a decrease in elastic fibers in the deep dermis and subcutis and Alcian blue revealed focally increased mucin in the subcutis. A diagnosis of SS was rendered. The patient was subsequently found to have renal involvement. Skin biopsies in early SS can reveal an increase in myofibroblasts confirmed by SMA. This differs from well established lesions of SS, which reveal a decrease in myofibroblasts and an increase in abnormal collagen. Loss of CD34 also correlates with disease extent and fibrosis. An inverse expression pattern of elevated SMA and decreased CD34 can indicate a diagnosis of early SS in patients who do not yet meet clinical criteria, highlighting the role of the dermatopathologist in early diagnosis.

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