Cancer-related problems are seen frequently by the emergency physician. More difficult presentations are seen with premonitory symptoms, paraneoplastic syndromes, and nonspecific lesions. Dermatologic paraneoplastic syndromes are numerous, nonspecific, and consist of hamartomatous growths, texture changes, new hair growth, or changes in skin color. Alteration of skin color may be of practically any color, localized or diffuse, and of sudden or indolent onset. Hormone production by tumors may lead to acne, hirsutism, gynecomastia, or a cushingoid appearance. Pruritus may herald the onset of leukemia or lymphoma and be intolerable, as with erythroderma. All suspicious presentations require thorough investigation for underlying disease. Metastasis to skin is not common and implies a poor prognosis if seen. Most metastases are seen on the head and neck, anterior chest wall, and abdomen. Basal cell and squamous cell carcinomas commonly occur in sun-exposed areas. Basal cell is locally destructive, whereas squamous cell occasionally metastasizes to local lymph nodes. Malignant melanoma is the leading fatal illness originating in skin, with a dramatic rise in incidence. It is classically described as asymmetric with irregular borders, is elevated, and shows color variegation; however, melanoma may present atypically, particularly in non-whites. Kaposi's sarcoma lesions are well-demarcated, symmetric, smooth nodules that appear purplish-brown, particularly if below the knee (owing to venous stasis). The closely interrelated structures of the eye and orbit are easily disturbed, leading to the presenting symptoms of visual disturbances, exophthalmos, pain, and ocular motility disorders. Primary tumors are not unusual and may include retinoblastoma, rhabdomyosarcoma, and melanoma. Equally common are metastatic lesions, most commonly lung and breast carcinoma. An estimation of the malignancy of bony lesions can be made by assessing the zone of transition, periosteal reaction, and bone destruction. A malignant lesion will more likely have a broad zone of transition, irregular periosteal reaction, and moth-eaten or permeative destruction of trabeculae. Metastatic bone lesions primarily occur in sites of persistent red marrow: skull, ribs, vertebrae, pelvis, and proximal humerus and femur. Bony lesions can be blastic or lytic in nature. Solitary pulmonary nodules that have not grown for 2 years can be assumed to be benign. Calcification seen on plain films are a strong (but not absolute) indication of benignancy. Lesions that are greater than 3 to 4 cm in diameter, have irregular contours, are cavitated with thick walls, have multiple peripheral nodules, and have lack of calcification are more likely malignant.