Histologic Diagnosis of Inflammatory Skin Diseases

Images

…hromomycosis Deep fungi are detected most readily in zones of suppuration, as pictured here, and in multinucleate histiocytes. 10.17.3A: Nodular dermatitis, granulomatous + 10.17.3B: Numerous yeasts in the cytoplasm of macrophages = Histopl…

Differential Diagnosis in Dermatopathology

Erythema nodosum vs. Nodular vasculitis

Infection of skin and subcutaneous tissue by atypical mycobacteria, that is, mycobacteria other than those responsible for tuberculosis and leprosy, expressed clinically as keratotic and crusted papules, plaques, nodules, and tumors that may be punc…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…10.22.5B: Hyphae in the cornified layer = Dermatophytosis Suppuration that begins in an infundibulum may extend upward and come to repose beneath the stratum corneum, the result being the subcorneal pustule illustrated here. 10.22.6A: Periv…

Histologic Diagnosis of Inflammatory Skin Diseases

Pyoderma gangrenosum

…character of the process no longer can be recognized because suppuration is so great. The elevated boggy border of the lesion is formed by dense diffuse infiltrates of neutrophils. That ulcer often extends well below the papillary dermis and explain…

Histologic Diagnosis of Inflammatory Skin Diseases

Sarcoidosis

…tous dermatitides that are sarcoidal, tuberculoid, or free of suppuration or necrosis fail consistently to reveal an infectious agent, no matter how many specialized stains are employed to detect them. For that reason, we do not search for organisms…

Differential Diagnosis in Dermatopathology

Perforating folliculitis vs. Elastosis perforans serpiginosa

Infection of skin and subcutaneous tissue by atypical mycobacteria, that is, mycobacteria other than those responsible for tuberculosis and leprosy, expressed clinically as keratotic and crusted papules, plaques, nodules, and tumors that may be punc…

Histologic Diagnosis of Inflammatory Skin Diseases

Erythema nodosum leprosum

…re dispersed widely in lobules. Erythema nodosum is devoid of suppuration, whereas erythema nodosum leprosum is typified by zones of suppuration. The infiltrate of inflammatory cells in the reticular dermis of erythema nodosum is scant, whereas that…

Histologic Diagnosis of Inflammatory Skin Diseases

Acne vulgaris

…ated infundibular epithelium in a vain attempt to contain the suppuration. The “pitted” scars of acne seen clinically result from fibrosis that follows on suppurative granulomatous inflammation, the loss of tissue and the retraction of th…

Differential Diagnosis in Dermatopathology

Acne vulgaris, erythematous papule vs. Rosacea, erythematous papule

Infection of skin and subcutaneous tissue by atypical mycobacteria, that is, mycobacteria other than those responsible for tuberculosis and leprosy, expressed clinically as keratotic and crusted papules, plaques, nodules, and tumors that may be punc…

Differential Diagnosis in Dermatopathology

Differential Diagnosis

…ic septa 5. Granulomas in lobules around foci of necrosis and suppuration 6. No vasculitis 6. Vasculitis of an artery in a septum in the subcutaneous fat 7. Necrosis of adipocytes slight, usually manifested as foam cells 7. Necrosis of adipocytes…