Differential Diagnosis in Dermatopathology

Discussions

Tuberculoid leprosy and sarcoidosis are granulomatous dermatitides that resemble one another histopathologically because both consist of aggregations of epithelioid histiocytes in the dermis and, sometimes, in the subcutaneous fat. Despite the simil…

Histologic Diagnosis of Inflammatory Skin Diseases

Leprosy

…many more macules that are scaly and that exhibit sensation. Sarcoidosis consists mostly of papules, rather than of nodules and tumors, that tend to become annular, and that lack alterations in sensation. Mycosis fungoides often displays patches, so…

Histologic Diagnosis of Inflammatory Skin Diseases

Applicable Terms

…nated tuberculoid. Sarcoidal granulomas are found not only in sarcoidosis, but also in foreign body responses to materials such as silica and beryllium. Tuberculoid granulomas are encountered in infectious diseases besides tuberculosis, among those b…

Histologic Diagnosis of Inflammatory Skin Diseases

Study By Disease

…(reticular erythematous mucinosis) (Quiz #759) Lupus pernio (sarcoidosis) (Quiz #137) Lupus profundus (panniculitis of lupus erythematosus) (Quiz #654) Lupus vulgaris (tuberculosis) (Quiz #136) Lupus vulgaris (tuberculosis) (Quiz #813) Lymphangioma,…

Histologic Diagnosis of Inflammatory Skin Diseases

Cells That Mediate Inflammation (Inflammatory Cells)

…s of an epithelium, e.g., as occurs with epithelioid cells in sarcoidosis. But other types of histiocytes also may participate in granulomatous inflammation, e.g., ones with foamy cytoplasm (Fig. 2.13), as is the case in lepromatous leprosy. Based on…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

-oid?

…sarcoma, and sarcoidal granulomas said to make up lesions of sarcoidosis are not always formed of epithelioid histiocytes (ones that are reputed to mimic the cells of an epithelium, but do not) devoid of an enveloping mantle of lymphocytes (so-calle…

Histologic Diagnosis of Inflammatory Skin Diseases

Syphilis

…not display plasma cells around venules. Tertiary syphilis Sarcoidosis displays little, if any, necrosis in the center of granulomas, lacks plasma cells, and usually is devoid of involvement of the epidermis. Clues to specific diagnosis histopatho…

Histologic Diagnosis of Inflammatory Skin Diseases

Erythema nodosum

…in septa of the subcutaneous fat and in the reticular dermis. Sarcoidosis in the subcutaneous fat affects lobules more than septa. Laboratory confirmation Verification is directed toward detection of a condition underlying, but none is found in most…

Histologic Diagnosis of Inflammatory Skin Diseases

Errors and Reasons

…a “lower” animal. Error: Darier-Roussy sarcoid is sarcoidosis. Reason: According to Rook’s textbook, it is “a misleading term, now obsolete, for a nonspecific subcutaneous lesion showing an epithelial-cell tuberculoid histolog…