Histologic Diagnosis of Inflammatory Skin Diseases

Subcutaneous fat necrosis of the newborn/ Poststeroid panniculitis

An inflammatory process that expresses itself in the skin in protean ways that are variations on a basic pathologic theme, and includes evanescent patches on the face (“butterfly blush”), scaly papules and plaques that resolve with atrop…

Histologic Diagnosis of Inflammatory Skin Diseases

a-1 antitrypsin deficiency

…ay be deep. Differential diagnosis histopathologic Factitious panniculitis of one type cannot be distinguished from α-1-antitrypsin deficiency, which prompts us to speculate that in some patients purported to have α-1-antitrypsin deficiency pannicul…

Histologic Diagnosis of Inflammatory Skin Diseases

Subcutaneous T-cell lymphoma

…gs being erythrophagocytosis and karyophagocytosis. Cytophagic panniculitis is no more a panniculitis than is mycosis fungoides or leukemia that happens to involve fat lobules extensively. Each is a malignant neoplastic process, not an inflammatory o…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…fects of exuberant suppurative infundibulitis. 10.38.5A: Panniculitis, lobular + 10.38.5B: A ring of histiocytes, many of them housing squames, around cornified contents of an infundibular cyst = Granulomatous panniculitis secondary to rupt…

Histologic Diagnosis of Inflammatory Skin Diseases

Behçet’s Disease

…logic Erythema nodosum is a granulomatous and fibrosing septal panniculitis, in contrast to the panniculitis of Behçet”s disease which, although septal mostly, is not granulomatous. Leukocytoclastic vasculitis also is characterized by nuclear &…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…secondary to wounds inflicted by the patient. 10.35.2A: Panniculitis, lobular + 10.35.2B: Foreign bodies (talc) in collections of neutrophils disposed in broad bands in fat lobules = Factitious panniculitis The clue to factitious panniculi…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…e characteristic of erythema nodosum, which, although a septal panniculitis mostly, often shows involvement of fat lobules, as is apparent in the photograph taken at scanning magnification. 10.33.2A: Panniculitis, mostly septal + 10.33.2B:…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

Images 10.71.1A: Vasculitis, large-vessel, and panniculitis, lobular mostly + 10.71.1B: Suppurative arteritis = Nodular vasculitis, early  The only condition characterized by suppurative arteritis and extensive panniculitis is nodular vas…

Histologic Diagnosis of Inflammatory Skin Diseases

Errors and Reasons

…pattern histopathologic of different causes. Error: Cytophagic panniculitis is a panniculitis. Reason: The so-called panniculitis is a T-cell lymphoma seated in the subcutaneous fat. Error: Dandruff is a disease. Reason: It is physiologic, equivalent…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…is a feature of a granulomatous and fibrosing dermatitis (and panniculitis). 10.20.10A: Diffuse dermatitis, granulomatous, and panniculitis, septal and lobular + 10.20.10B: Predominance of foamy histiocytes, many with strikingly abnormal n…