Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Skin: Nodular and Diffuse Dermatitis

….174 A&B. Figure 5.174 A&B. Nodular dermatitis and diffuse dermatitis. Nodular dermatitis is distinguished from perivascular dermatitis (see Fig. 5.16 A&B) by the density of the infiltrate of inflammatory cells. In the perivascular der…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Trichodiscoma Related to the Hair Disk and Merkel-Cell Neoplasm to Merkel Cells?

…n: A tumor thought to arise from the cutaneous Merkel cell, a neuroendocrine cell.” MacKie RM. Epidermal skin tumors. In: Champion EH, Burton JL, Ebling FJG, eds. Textbook of Dermatology. 5th ed. Oxford, England: Blackwell Scientific Publicati…

Histologic Diagnosis of Inflammatory Skin Diseases

Algorithms Predicated on “Nonspecific” Findings

…ytes often in mitosis = Lymphomatoid papulosis + Nodular or diffuse infiltrate of abnormal lymphocytes; lymphocytes often in the epidermis, sometimes in collections there = Mycosis fungoides     Acantholytic Cells in the Midst of Neutr…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…shown in the second set of photomicrographs. 11.23.4A: Diffuse dermatosis + 11.23.4B: Predominance of mast cells = Urticaria pigmentosa ¬†This particular expression of urticaria pigmentosa is superficial, dense, and diffuse, in contrast to…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Telogen Effluvium—An Inflammatory Disease?

…; Telogen effluvium is characterized clinically by temporary, diffuse, and sparse loss of hair that, as a rule, does not result in striking baldness. Only occasionally is the alopecia restricted clinically to a specific area (such as the occiput in n…

Histologic Diagnosis of Inflammatory Skin Diseases

Mycosis fungoides

…ratotic, or both together Nodules and tumors Nodular and/or diffuse infiltrates of atypical lymphocytes throughout the dermis and sometimes in the subcutaneous fat Lymphocytes sometimes in lichenoid array; some dermal papillae stuffed by lymphocyte…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…ompany with cholesterol clefts, and hairs situated in a dense diffuse infiltrate of histiocytes mostly = Foreign body reaction to ruptured infundibular cyst Sebaceous secretion is transported normally along sebaceous ducts to infundibula. It is not s…

Histologic Diagnosis of Inflammatory Skin Diseases

Xanthogranuloma

…omorphous Some histiocytes in mitosis Fully developed Dense diffuse infiltrate of histiocytes Many histiocytes with foamy cytoplasm Some histiocytes Touton in type; many of them sometimes Infiltrate of histiocytes sometimes abutting the epidermis a…