Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Keratosis Lichenoides Chronica?

…, a partly acanthotic epidermis, hydropic degeneration of the basal cell layer resulting in cleft formation and a band-like mononuclear infiltrate confusing the dermo-epidermal interface.” Van De Kerkhof PCM. Spontaneous resolution of keratosi…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Lentigo?

…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…

Dermatology Practical & Conceptual

Yellow color upon dermatoscopy does not exclude melanoma!

…ratinizing tumors including seborrheic keratosis and squamous cell carcinoma or in tumors with sebaceous differentiation, but also in juvenile xanthogranuloma or granulomatous skin diseases [1]. It is more surprising that recent dermatoscopic observa…

Differential Diagnosis in Dermatopathology

Guttate psoriasis vs. Guttate (dermatosis) parapsoriasis

Extramammary Paget’s disease is an apocrine carcinoma that begins within the epidermis and presents itself clinically as a patch or a subtle plaque that extends centrifugally for many years before becoming a readily discernible thick plaque, a…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…lated to the fundamental process pathologic. 10.63.18A: Nodular dermatitis, granulomatous + 10.63.18B: Foci of extensive degeneration of collagen surrounded by histiocytes arrayed in a palisade and thrombi in the lumen of small vessels = Lu…

Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Skin: Fibrosing Dermatitis

…which are fibrin and crust, and at the side of which is pseudocarcinomatous (infundibular) proliferation of keratocytes. Figure 5.355 A&B. Repair of chondrodermatitis nodularis helicis: fibroplasia characteristic of mending of an ulcer inflict…

Histologic Diagnosis of Inflammatory Skin Diseases

Epidermolysis bullosa simplex

…pathologic Early Tiny vacuoles in the cytoplasm of epidermal basal cells and no infiltrate of inflammatory cells in the dermis Fully developed Dermal papillae preserved beneath what seems, at first blush, to be a subepidermal blister Vacuoles in e…

Dermatology Practical & Conceptual

Melanoma arising in a giant nevus spilus maculosus

…vus showed elongation of rete ridges and hyperpigmentation of basal keratinocytes but no substantial proliferation of melanocytes (Figure 5). Histopathology of the nodule showed a nodular melanoma with an invasion thickness of 4.5 mm (Figure 6). On t…