Clear Cell Neurofibroma: A Rare and Confusing Variant.

Clear cell change has been demonstrated in many cutaneous entities; however, there have been only two reports of clear cell neurofibroma. We present the third case of this unusual subtype. A 25-year-old female presented clinically with a picture of neurofibromatosis Type 1 including multiple cutaneous nodules. Biopsy from one of these nodules revealed a normal epidermal covering and a dermal benign neoplastic growth formed of a mixture of spindle cells and clear cells showing vacuolated cytoplasm. The neoplastic cells showed round nuclei with prominent nucleoli. Immunohistochemical staining showed positivity to S-100 and CD68 with negative expression of calretinin, CK, Melan-A, HMB-45, CD34, and smooth muscle actin. Clear cell neurofibroma should be considered in dealing with clear cell cutaneous lesions, giving attention to characteristic clinical, histopathological, and immunohistochemical features. CD68 could be expressed in neurofibroma, and this should not be misinterpreted as a histiocytic lesion.