Differential Diagnosis in Dermatopathology

Discussions

…of 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 erosi…

Histologic Diagnosis of Inflammatory Skin Diseases

Pityriasis rubra pilaris

…dibula 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…

Histologic Diagnosis of Inflammatory Skin Diseases

Blood Vessels

…lectron 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 ve…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…ollagen 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 basa…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Mycosis Fungoides—Increasing in Incidence?

“Mycosis fungoides does appear to be increasing in frequency more rapidly than lymphoma in general.” Weinstock MA. Epidemiology of mycosis fungoides. Semin Dermatol 1994;13(3):154–59. “The incidence [of mycosis fungoides…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Overlap Syndromes?

…s and Bowen’s disease, and both seborrheic keratosis and basal-cell carcinoma. Very rarely, that may be true for seborrheic dermatitis and psoriasis, but the collision is a happenstance, not an overlap as that word is applied in “overlap…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Lentigo?

…n 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 elo…

Differential Diagnosis in Dermatopathology

Discussions

…osis, a thickened epithelium, and an infiltrate of mononuclear cells. The white color (leuko-) in both leukokeratosis and leukoplakia results from abnormal production and maceration of cornified cells. But the essential character of the two condition…