Acne fulminans is the most aggressive and destructive form of acne vulgaris, being also known as acne maligna. The onset is acute and systemic involvement is always present. Most commonly, acne fulminans (AF) occurs in male adolescents as a brutal complication of a preexisting mild or moderate acne. The etiology of AF remains incompletely elucidated. The skin lesions are polymorphic, the symptoms and clinical signs vary, and thus the diagnosis is not easy. In making a certain diagnosis of AF, histopathology has a decisive role. In this respect, we will present some of the most suggestive aspects of histopathology, immunohistochemistry and electron microscopy in a 16-year-old patient clinically diagnosed with AF. This patient presented on admission nodular inflammatory and ulcerative necrotic lesions on the face and chest, extremely, accompanied by significant myalgias and arthralgias.