Abstract
Painful tumors of the skin present as dermal or subcutaneous nodules. They can originate from several sources: adipose tissue, cartilage degeneration, deposition of bone or calcium, eccrine glands, fibrous tissue, infiltration of benign (endometrium) or malignant (metastatic neoplasm) tissue, muscle, nerve, or vascular structures. Although pathologic evaluation of the lesion is necessary to determine the diagnosis, it is possible to make a reasonable differential diagnosis based on knowledge of prior tumors that have appeared as tender lesions. Two women with painful skin tumors - either osteoma cutis or an organizing thrombus - are described. Based on our clinical experience and review of the literature, 25 painful skin tumors were identified: chondrodermatitis nodularis helicis, angioendotheliomatosis, leiomyoma, metastases, hidradenoma, osteoma cutis, glomus tumor, fibromyxoma, leiomyosarcoma, eccrine angiomatous hamartoma, Dercum's disease, peizogenic pedal papule, neurilemmoma, angiolipoma, neuroma, dermatofibroma, granular cell tumor, endometriosis, thrombus, scar, blue rubber bleb nevus, angioma, calcinosis cutis, and keloid. An acronym - inspired by Charlotte's Web, a book that many children have read - that can be used as a memory aid for recalling the list of painful skin tumors is introduced: "CALM HOG FLED PEN AND GETS BACK".