Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Skin: Vesicular Dermatitis

…ipient acantholysis becomes manifest. Figure 5.265 A&B. Necrosis of keratocytes en masse yet still diagnosable: infection by herpesvirus. Cytopathic effects of herpesvirus may eventuate in extensive necrosis of keratocytes but, en route to tha…

Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Subcutaneous Fat: Panniculitis

…ei, but all, nonetheless, being indicative beyond doubt of fat necrosis: Figure 5.401 Five signs of necrosis of adipocytes. A. Granular fat necrosis. B. Fat “microcysts.” C. Membranous fat necrosis. D. Foamy histiocytes (foam cells, li…

Histologic Diagnosis of Inflammatory Skin Diseases

Poststeroid panniculitis

…opathologic Findings are the same as those in subcutaneous fat necrosis of the newborn. Correlation clinicopathologic Discrete nodules of poststeroid panniculitis, like those of subcutaneous fat necrosis of the newborn, are constituted of patchy infi…

Histologic Diagnosis of Inflammatory Skin Diseases

Errors and Reasons

…llagen, is responsible for anetoderma. Error: Apoptosis is not necrosis. Reason: In classic Virchowian pathology, necrosis is characterized cytopathologically by three signs, namely, pyknosis, karyorrhexis, and karyolysis; apoptosis is typified by py…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…matitis, spongiotic and psoriasiform + 10.23.7B: Confluent necrosis with a ragged base in the upper part of the viable epidermis = Response to excoriation The character of the necrosis in the upper part of the epidermis is a sure sign of a reacti…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Necrobiosis?

…neral pathology in this regard is definition of necrobiosis as necrosis of collagen, rather than as degeneration of that fibrous protein. Collagen is a fiber and, unlike the fibrocytes that produce it, cannot undergo necrosis; only viable cells can s…

Histologic Diagnosis of Inflammatory Skin Diseases

Algorithms Predicated on “Nonspecific” Findings

…illaries, innumerable extravasated erythrocytes, and epidermal necrosis; few, if any, inflammatory cells = Disseminated intravascular coagulation/Coumarin necrosis/Thrombotic thrombocytopenic purpura + Thrombi in only a few venules situated beneath…

Histologic Diagnosis of Inflammatory Skin Diseases

Sclerema neonatorum

…lefts in radial array in nearly every adipocyte in fat lobules Necrosis of adipocytes as evidenced by the presence of fat “microcysts” Sparse infiltrate of neutrophils, especially in zones of fat necrosis; some mononuclear and multinuclea…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Necrotizing Vasculitis?

…intriguing. Does it mean that the vasculitis is accompanied by necrosis of blood vessels or that the vasculitis causes necrosis? Can blood vessels undergo necrosis? Is “necrotizing vasculitis” a distinctive phenomenon or is it simply a sy…