geographic pattern

A term used in various specialties as a general descriptor for lesions in which large areas of one colour, histologic pattern or radiologic density with variably scalloped borders sharply interface with another colour, pattern or density, fancifully likened to national boundaries and/or coastlines
Dermatology A pattern of skin involvement in psoriasis
Forensics A descriptive term for the variegated pattern of skin ulceration seen in drug addicts who inject heroin subcutaneously (skin popping) which may be surrounded by an ‘ameboid’ rim of hyperkeratotic and inflamed skin
Imaging Broad areas of patchy destruction, seen in such diverse conditions as Gaucher disease, Langerhans cell histiocytosis, osteolytic tumours (e.g., metastatic bronchogenic carcinoma and osteosarcoma)
Pathology Sharply defined ‘fjord-like’ histologic separation of one tissue morphology from another, seen at low-power (40x) in the following:
Lymph nodes Lymphogranuloma venereum (LGV), less commonly in cat-scratch disease
Lungs Wegener’s granulomatosus where irregular necrotic patches are interspersed with scattered islands of preserved pulmonary parenchyma, also described in rare fulminant pulmonary infections
Soft tissue Epithelioid sarcoma (ES), in which geographic lesions may result from fusion of several necrotizing nodules, often accompanied by hemorrhage and cystic degeneration; the geographic islands have central necrosis and are rimmed by chronic inflammation. ES is a slow-growing malignancy of young adults, often of the upper extremities; the prognosis is poor if necrosis is present

Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

geographic pattern

A general descriptor for lesions in which large areas of one color, histologic pattern, or radiologic density with variably scalloped borders sharply interface with another color, pattern or density, fancifully likened to national boundaries and/or coastlines Imaging Broad areas of patchy destruction, seen in such diverse conditions as Gaucher disease, histiocytosis X, osteolytic tumors–eg, metastatic bronchogenic carcinoma and osteosarcoma.

McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.