To the Editor:
Dermatofibromas, the most common fibrohistiocytic tumors of the skin, are typically solitary lesions. Clustering of and multiple dermatofibromas (multiple eruptive dermatofibromas [MEDFs]) are relatively less common. The association between MEDF and systemic immunoaltered disease states such as systemic lupus erythematosus (SLE) or human immunodeficiency virus infection has been described and led to speculation that MEDF might be a result of an abnormal immune response. We report a patient with sarcoidosis who developed multiple large dermatofibromas, some clustered, on the neck, left shoulder, and back.
Figure 1. Two large, firm, hyperpigmented nodules on the left shoulder, one with overlying erythema and mild scale (A and B).
A 61-year-old woman with a history of mild pulmonary sarcoidosis confirmed by transbronchial biopsies presented to our clinic with a 2-year history of hyperpigmented papules on the trunk and extremities with subjective enlargement and increased erythema of a papule on the left shoulder over the last 6 months. She had associated pain and pruritus in the area. She was not on any systemic medications for sarcoidosis at the time. Physical examination revealed 2 large, firm, hyperpigmented nodules on the left shoulder, one with overlying erythema and mild scale (Figure 1). There also were multiple scattered hyperpigmented papules on the back, chest, and right arm that dimpled when compressed. A biopsy was obtained because of clinical concern for cutaneous sarcoidosis. Histopathologic evaluation of the largest nodule demonstrated epidermal hyperplasia with effacement of the rete ridges and a proliferation of spindle cells that wrapped around collagen fibers in the dermis, consistent with a dermatofibroma (Figure 2).
Figure 2. Punch biopsy from the papule on the shoulder demonstrated hyperkeratosis, blunting of the rete ridges, and an increase in fibroblast proliferation throughout the dermis without infiltration into the fat (H&E, original magnification ×40).
Dermatofibromas are common fibrohistiocytic neoplasms in the skin that typically present as a solitary lesion. A clustering of dermatofibromas, MEDFs, is relatively less common, representing only 0.3% of all dermatofibromas.1,2 Histopathologically, similar to solitary dermatofibromas,3 MEDF has classically been defined as more than 15 lesions, though another definition includes the appearance of several dermatofibromas over a relatively short period of time.2