Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Hyalin?

“With the high power the hyaline is seen in very varied forms, which all show the same fuchsin red reaction. The first forms a section by itself; it comprises hyaline balls of different size, which lie free between the epithelial cells, and w…

Histologic Diagnosis of Inflammatory Skin Diseases

Erythema nodosum leprosum

…e from specimens of erythema nodosum leprosum does reveal some fibrin in the wall of small vessels and thrombi in some of their lumen. In most specimens, however, there are no signs of indubitable leukocytoclastic vasculitis, namely, venules with fib…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Necrobiosis?

“This latter category, where the cells are destroyed during the course of the process, I proposed a few years ago to designate by a term which has been employed to express disease generally by K. H. Schultz, viz., necrobiosis. Necrobiosis is…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Wegener’s Granulomatosis?

“Inside the nose besides extensive necrosis, there is a cell-rich granulomatous tissue with granulomatous epithelioid cell foci which surround the vessels. . . . In both lungs: infarct-like necrosis in which one finds severe changes in the ve…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Urticarial Vasculitis?

“Although necrotizing angiitis (vasculitis) of the superficial venules and capillaries of the skin is usually appreciated visually as a purpuric papule, a group of patients has been defined in whom all of the skin lesions were urticarial. Mic…

Differential Diagnosis in Dermatopathology

Discussions

Leukocytoclastic vasculitis and livedo vasculitis, as their names denote, are vasculitides that favor the lower extremities, but whereas only the legs are affected as a rule in livedo vasculitis, any anatomic site may be involved by leukocytoclastic…

Differential Diagnosis in Dermatopathology

Leukocytoclastic vasculitis vs. livedo vasculitis

A type of small-vessel vasculitis (venulitis) of the skin, occurring especially in the vicinity of the ankle, characterized at first by purpuric macules and patches that, in time, may become hemorrhagic blisters that ulcerate and heal with white, st…

Differential Diagnosis in Dermatopathology

Discussions

Lesions of granuloma annulare that involve the subcutaneous fat mostly have many findings in common with rheumatoid nodule. Both diseases are associated with epithelioid histiocytes arrayed in a palisade around zones of degenerated collagen, mucin,…

Histologic Diagnosis of Inflammatory Skin Diseases

Selection of the Site

Because many inflammatory diseases of the skin, e.g., dermatitis herpetiformis, nummular dermatitis, scabies, Grover’s disease, and eosinophilic folliculitis, are exquisitely pruritic, scratching is an inevitable consequence, and signs of exco…

Differential Diagnosis in Dermatopathology

Dermatitis herpetiformis vs. Bullous pemphigoid

A type of small-vessel vasculitis (venulitis) of the skin, occurring especially in the vicinity of the ankle, characterized at first by purpuric macules and patches that, in time, may become hemorrhagic blisters that ulcerate and heal with white, st…