Solitary cutaneous pilar leiomyoma: A rare entity with review of literature

Cutaneous leiomyomas are uncommon, benign smooth muscle neoplasm and comprise approximately 5% of all leiomyomas. Pilar leiomyoma is the most common type of cutaneous leiomyoma and arises from arrector pili muscle in the skin. Cutaneous pilar leiomyomas present in second and third decades of life as multiple, painful red-brown papulonodular lesions on the trunk or extremities. Clinically this lesion is easily misdiagnosed for other cutaneous conditions. Hence, this lesion should always be taken into consideration in the clinical differential diagnosis of papulonodular skin lesions. Herein, we report a case of 34-year-old male who presented with a small nodule on his left arm. Clinically differential diagnosis was fibroma or neuroma. Surgical excision was performed. Histopathological examination, special stain (Masson's trichrome) and Immunohistochemistry confirmed the diagnosis of cutaneous pilar leiomyoma.