Dermatology Practical & Conceptual

The so-called dysplastic nevus is not dysplastic at all

…eoplasia with cytomorphologic features of malignancy, namely, carcinoma in situ lesions, by surgical pathologists. If one looks for an equivalent lesion to the so-called dysplastic (carcinoma in situ) lesions of epithelial tissue in melanocytic neopl…

Differential Diagnosis in Dermatopathology


…f sebaceous hyperplasia may be misinterpreted clinically as a basal-cell carcinoma because both conditions have a slightly elevated border and a central dell. In basal-cell carcinoma, however, the depression in the center usually represents an erosio…

Histologic Diagnosis of Inflammatory Skin Diseases

Radiation dermatitis and panniculitis

…se Protracted Variations clinical Malignant neoplasms such as basal-cell carcinoma, squamous-cell carcinoma, melanoma, fibrosarcoma, and malignant fibrous histiocytoma may develop in zones of radiation sclerosis. Differential diagnosis clinical Morph…

Histologic Diagnosis of Inflammatory Skin Diseases

Blood Vessels

…ectron microscopy to consist of a single layer of endothelial cells that line a narrow lumen, those cells being surrounded by a layer of pericytes (Fig. 1.78). The endothelial cells and pericytes are enveloped by a basal lamina. In the descending ven…

Histologic Diagnosis of Inflammatory Skin Diseases


…llagen in the upper part of the dermis, of lymphocytes in the basal layer, and of elongated mounds of parakeratosis militate against that diagnosis. 10.80.2A: Perivascular dermatitis, slightly spongiotic + 10.80.2B: Lymphocytes in the basal

Histologic Diagnosis of Inflammatory Skin Diseases

Pityriasis rubra pilaris

…ibula dilated and plugged by orthokeratotic and parakeratotic cells in a manner similar to that in the epidermis Late All the findings in lesions developed fully, except mitotic figures are not present above the basal layer, and there is no pallor…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology


…of the rete pegs and melanocytic hyperplasia confined to the basal cell layer.” Farmer ER, Hood AF. Melanocytic tumors. In: Farmer ER, Hood AF, eds. Pathology of the Skin. New York, NY: McGraw-Hill, 2000:1108. “Solar lentigo shows elon…

Differential Diagnosis in Dermatopathology

Guttate psoriasis vs. Guttate (dermatosis) parapsoriasis

A disease manifested chiefly in the skin by vesicles and bullae that appear on sites of trauma, especially the face and dorsa of the hands, often in conjunction with macular hyperpigmentation and hypertrichosis of a face and sclerodermoid changes on…