Critical skin cancer in organ transplant recipients--a dermatopathological view.

Organ transplant recipients (OTR) are at significantly increased risk to develop a wide variety of skin cancers, particularly epithelial skin cancer, Merkel cell carcinoma and Kaposi's sarcoma. In addition, melanoma, skin adnexal neoplasm and cutaneous lymphomas are more common in OTR and may differ in their clinicopathological presentation from tumors in immunocompetent patients. The accuracy of clinical diagnosis of suspected premalignant and malignant skin lesions in OTR is modest. Therefore, histopathological diagnosis is an essential element for the diagnostic workup of skin cancers, and additionally provides important information on prognosis. This review discusses the histopathological aspects of skin cancers in OTR, the impact of dermatopathological analysis on prognosis and understanding of the pathogenesis of these neoplasms.