Histologic Diagnosis of Inflammatory Skin Diseases

Images

…y at the site. At the periphery of the lesion, fibrocytes and histiocytes are splayed between thickened bundles of collagen. Above the dermal component, the epidermis is acanthotic and hyperkeratotic. Marked compact orthokeratosis signifies that the…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…, neutrophils, and eosinophils in company with fibrocytes and histiocytes, the latter being predominant = Interstitial granulomatous dermatitis with arthritis Some histiocytes have abnormal nuclei and some of them are in mitosis. Histiocytes tend to…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…undles of collagen oriented parallel to the skin surface, and histiocytes, some of them multinucleate, around a hair = Scar and foreign body reaction to hair The presence of hair shafts in the scar indicates that the inflammatory process was initiate…

Histologic Diagnosis of Inflammatory Skin Diseases

Xanthomas

…ellow color of lesions results from lipid in the cytoplasm of histiocytes and, in the case of eruptive xanthomas, lipid free in the tissue as well. Differential diagnosis histopathologic Lepromatous leprosy sometimes consists of histiocytes that are…

Histologic Diagnosis of Inflammatory Skin Diseases

Syphilis

…osis fungoides consists of lymphocytes mostly, rather than of histiocytes and plasma cells. Mucha-Habermann disease is composed almost entirely of lymphocytes, rather than mostly of histiocytes and plasma cells. Psoriasis lacks plasma cells and h…

Histologic Diagnosis of Inflammatory Skin Diseases

Leprosy

…in the reticular dermis and, sometimes, the subcutaneous fat. Histiocytes monopolize in lepromatous leprosy, but in tuberculoid leprosy they are joined by moderately dense infiltrates of lymphocytes. In lepromatous leprosy in reaction, dense infiltra…

Histologic Diagnosis of Inflammatory Skin Diseases

The Algorithmic Method

…rm dark nucleus and negligible cytoplasm) (Fig. 6.1 A&B); histiocytes are pale (because their nuclei are pale and their abundant cytoplasm is even paler) (Fig. 6.2 A&B); plasma cells are paler than lymphocytes but darker than histiocytes and,…

Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Subcutaneous Fat: Panniculitis

…ranuloma annulare, typified by lymphocytes around venules and histiocytes in palisaded array around a discrete locus replete with mucin, may be confined entirely to the dermis, as shown here. Figure 5.394 A&B. Granuloma annulare: dermal and su…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…Nodular dermatitis, granulomatous + 10.95.1B: Epithelioid histiocytes aligned in a palisade around foci of degenerated collagen and necrosis of inflammatory cells, the histiocytes in turn being encircled by lymphocytes = Sarcoidosis ¬†Tuberculoid…

Histologic Diagnosis of Inflammatory Skin Diseases

Sarcoidosis

…s histopathologic Fully developed Collections of epithelioid histiocytes throughout the dermis and sometimes throughout lobules of the subcutaneous fat; granulomas usually discrete, but may be confluent Tiny focus of necrosis in the center of collec…