Benign Epidermal, Mesenchymal Skin Tumors, and Cysts

Benign epidermal and adnexal skin tumors originate from epidermal and adnexal structures and are one of the most common tumors encountered by dermatologists. Seborrheic keratosis is the most frequent benign epidermal tumor mainly seen in adults. Adnexal tumors encompass a large group of benign and malignant follicular, sebaceous, and sweat gland tumors. Mesenchymal tumors are soft-tissue tumors that arise from connective tissue. Common benign mesenchymal tumors include fibroma, dermatofibroma, lipoma, neurofibroma, and leiomyoma. Cysts are cavitary lesions filled with fluid or semi-solid material and have a broad clinical spectrum. Epidermal cysts, milia, and trichilemmal cysts (atheroma) are the most frequent types of cysts. Diagnosis is usually based on history and clinical aspects. A pathohistological examination is not always necessary; however, if the clinical diagnosis is uncertain or the lesions are suspicious for malignancy, a skin biopsy should be performed. In most cases, the treatment options are surgical removal with cryotherapy, electrosurgery, or laser ablation.