BackgroundMycosis fungoides (MF) is the most common subtype of cutaneous T‐cell lymphoma and is often difficult to diagnose. Early‐stage disease is particularly challenging and requires clinical and histopathologic correlation to make an accurate diagnosis. In order to facilitate the diagnosis of early MF, an algorithm has been proposed by the International Society for Cutaneous Lymphomas (ISCL) whereby clinical and histopathologic characteristics as well as immunohistochemistry and T‐cell receptor gene rearrangement studies may be applied to suspected cases of MF. The diagnostic utility of this algorithm has not yet been validated. We sought to determine the validity of the proposed algorithm via an investigator‐blinded, retrospective, case‐control study.MethodsA total of 34 cases were randomly selected from the database of a clinic for cutaneous T‐cell lymphomas and included patients with MF and patients with clinicopathologic mimics. The proposed diagnostic algorithm was systematically applied to the entire cohort. Each case was assigned a composite score based on the parameters in the proposed algorithm.ResultsAmong the 24 cases of MF, 21 cases achieved four or more points through application of the algorithm. Among the 10 cases of MF mimics, only four achieved four or more points. This difference was significant (Fisher's exact test, p = 0.009). The sensitivity of the 4‐point threshold for a diagnosis of MF was 87.5% and the specificity was 60%.ConclusionsThe diagnostic algorithm proposed by the ISCL is a statistically valid method for defining cases of early MF and distinguishing these cases from other benign dermatoses. However, the clinical utility of the algorithm may be limited by its low specificity. Further refinement of the algorithm may improve its accuracy.

Skin neoplasms are common concerns for which patients seek medical, attention. Familiarity with these benign and, malignant tumors is essential for appropriate evaluation and management., In the current era, skin cancer is the most common neoplasm in humans - more than 1 million new cases will be diagnosed in the United States this year. Pigmented lesions pose a particular challenge because melanoma, the potentially lethal form of skin cancer, is always part of the differential diagnosis. Fortunately, early detection and prompt treatment of skin cancer, especially in the case of melanoma, improve overall prognosis and survival.This chapter reviews the epidemiology, pathogenesis, clinical presentation, histopathology, and management of common benign and malignant skin tumors including seborrheic keratoses, melanocytic nevi, actinic keratoses, melanophytic nevi, actinic keratoses, squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and melanoma.

LEARNING OBJECTIVES:At the conclusion of this learning activity, physician participants should be able to assess their own diagnostic and patient management skills and use the results of this exercise to help determine personal learning needs that can be addressed through subsequent CME involvement. Instructions for claiming CME credit appear in the front advertising section. See last page of Contents for page number. Instructions: In answering each question, refer to the specific directions provided. Because it is often necessary to provide information occurring later in a series that give away answers to earlier questions, please answer the questions in each series in sequence.

Learning objectives: At the conclusion of this learning activity, physician participants should be able to assess their own diagnostic and patient management skills and use the results of this exercise to help determine personal learning needs that can be addressed through subsequent CME involvement. Instructions for claiming CME credit appear in the front advertising section. See last page of Contents for page number. Instructions: In answering each question, refer to the specific directions provided. Because it is often necessary to provide information occurring later in a series that give away answers to earlier questions, please answer the questions in each series in sequence. Learning objectives: At the conclusion of this learning activity, physician participants should be able to assess their own diagnostic and patient management skills and use the results of this exercise to help determine personal learning needs that can be addressed through subsequent CME involvement. Instructions for claiming CME credit appear in the front advertising section. See last page of Contents for page number. Instructions: In answering each question, refer to the specific directions provided. Because it is often necessary to provide information occurring later in a series that give away answers to earlier questions, please answer the questions in each series in sequence.