Key Points Cutaneous T-cell lymphoma (CTCL) is a malignant neoplasia of T cells with homing features in the skin. Mycosis fungoides and Sézary syndrome are the most common variants of CTCL. Mycosis fungoides is often a slow-growing, indolent epidermotropic malignancy,…
Key Points Cutaneous pseudolymphomas are benign inflammatory skin diseases that mimic malignant lymphomas either clinically, histopathologically, or both. Cutaneous pseudolymphomas should be classified precisely according to specific clinicopathologic entities. Integration of clinical, histopathologic, immunophenotypic and molecular genetic features is crucial…
Key Points Epidermodysplasia verruciformis (EV) is a genetic lifelong disease associated with specific human papillomaviruses (HPV) and multiple skin cancers. Immunosuppressed patients have an increased risk of developing EV lesions. Bowenoid papulosis presents as wart-like papules usually affecting the genitals…
Key Points Clinical presentation is frequently a red- to purple-colored macule, plaque or nodule. Helpful diagnostic clues include sharp circumscription versus infiltrative edges of the neoplasm, size and multicentricity, as well as site of involvement, age, and other associated disease…
Key Points Merkel cell carcinoma (MCC) is an uncommon neuroendocrine skin cancer with a 5-year disease-associated mortality of 46%. The reported incidence of MCC has tripled in the past 20 years and there are approximately 1500 new cases each year…
Key Points Kaposi's sarcoma is a multicentric, mostly oligoclonic neoplastic proliferation of endothelial cells that have been infected and transformed by human herpesvirus-8. Four epidemiologic types of Kaposi's sarcoma are recognized: classic (typically found sporadically in elderly persons of Mediterranean…
Key Points Sarcomas of the skin comprise numerous rare entities that commonly present as nodules or plaques. Cutaneous sarcomas exhibit differentiation toward a variety of mesenchymal lineages. Dermatofibrosarcoma protuberans, atypical fibroxanthoma, and cutaneous leiomyosarcoma are the most common types. Diagnosis…
Key Points Mammary Paget's disease (MPD) is almost always associated with underlying breast carcinoma. If an underlying mass is palpated, the patient should be referred for a fine needle biopsy of the mass or an excisional biopsy. The immunostaining pattern…
Key Points Adnexal carcinomas are rare and often misdiagnosed both clinically and histologically. Lesions can develop de novo or in conjunction with a pre-existing benign adenoma. Recognition and separation of these lesions into distinct entities is important, given the therapeutic…
Key Points The incidence of squamous cell carcinoma (SCC) is rising and thought to occur secondary to numerous factors including increasing UV exposure, prevalence of human papillomavirus, and immunosuppression. Awareness of the varied clinical and histologic presentations of SCC is…