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C003 Histopathology of the alopecias
s59
Courses Dermatopathology - Update ElCOO1 Lymphoproliferative J. Conor O’Keane. Pathology University
College
Dublin,
disorders
Department, Ireland
Mater
Hospital,
Cutaneous lymphoproliferative disorders challenge many clinical and pathological concepts derived from lymphoproliferative disorders of lymph nodes. Cutaneous T cell lymphoma: Confounding variables include patient threshold for complaint, clinical threshold for biopsy and pathologic threshold for atypia. Many cases atypical clinically are also atypical histopathologically. Antigen deletion and T cell receptor gene rearrangements are identified in a number of inflammatory, as well as neoplastic dermatoses. Cutaneous B cell lymphoma is often secondary or the first manifestation of systemic B cell lymphoma. The concept of skin associated lymphoid tissue has some validity. Pseudolymphoma is a diagnosis which requires further definition analogous to a diagnosis of anaemia. CD30 positive lymphoproliferative disorders of skin include Hodgkin’s disease, lymphomatoid papulosis and large cell lymphoma. In contrast to systemic CD30 positive lymphoma, primary C30 positive skin lymphoma has a good prognosis if it occurs separately from mycosis fungoides. Summary: Modem diagnostic techniques still require careful clinicopathologic and light microscopic correlation to arrive at precise diagnosis. I COO2 Vasculitis: A differential diagnostic
approach
B. Zelger. Department Innsbruck,
Innsbruck,
of Dermatology, Austria
University
of
Vasculitides can present with a wide variety of clinicopathologic features. Using vasculitis allergica as a model a differential diagnostic approach of cutaneous and systemic vasculitides is presented. Vasculitis allergica is a common vasculitic problem of capillaries and postcapillary venules with an incidence of six patients per 100.000 people annually. Palpable purpura and leukocytoclastic vasculitis are the characteristic clinical and histological findings of this polyetiologic (infections, drugs, alimentary ingredients, connective tissue disorders, neoplasms) immunocomplex mediated disease. Unusual clinical presentations include urticarial vasculitis and erythema gyratum repens. Histologic peculiarities include the immunoglobulin A positive pupura Schonlein-Henoch as well as the fibrin thrombi rich variants of cryoglobulinemic (hepatitis C!) and hypergam-
maglobulinemic (plasmocytoma; connective tissue disorders) vasculitides. Moreover, in rare cases (~5%) vasculitis allergica can present in patients with more serious systemic arteritides such as Wegener’s granulomatosis (cANCA). Corticosteroids are in more than 90% of patients an effective curative therapy. Adverse outcome is mostly due to long term renal problems. I COO3 Histopathology Rino Cerio. England
of the alopecias
Dermatopathology can be helpful in the diagnosis of several scalp diseases but is often dependent on the quality of the biopsy. It may also have a role in the investigation into pathogenesis of disease. Follicular plugging, increased fibrous tracts as highlighted by elastic stains, and decreased anagen follicles are common to most patterns of alopecia. The introduction of transverse sectioning of scalp biopsies by Headington allows measurement of mean hair shaft diameter and the density of anagen follicles and follicular structures, all of which are diminished in androgenic alopecia. Accurate anagen/telogen counts are also available from this method. In active alopecia areata histology reveals lymphocytes surrounding catagen and anagen hair bulbs with at least 50% of follicles in catagemtelogen. The addition of immunofluorescence allows distinction between lichen planopilaris, discoid lupus erythematosus and cicatricial pemphigoid whilst the presence of massive lymphocyte-mediated apoptosis is present during the early stages of pseudopelade. Many cases of “thumbprint” scaring alopecia (clinical pseudopelade) are “burnt out” LP or DLE pathologically. The remainder heterogenous and often no cause is found. Hair-follicle hamartomas, metastic tumours, follicular mucinosis, scleroderma and granulomatous diseases are other conditions where histopathology plays a major part in the diagnosis of alopecia.
COO4 Differential diagnosis of auto-immune subepldermal blisters PH. McKee. St. Thomas’
Hospital,
London,
UK
Subepidermal blisters may be inflammatory or non-inflammatory The former commonly have an immunologically and frequently auto-immune mediated pathogenesis while the latter usually do not. There are however occasional exceptions to the rule. Inflammatory variants are often divided into neutrophilrich eosinophil-rich and lympho-histiocytic mixed categories. Histological assessment often points towards a specific diagnosis but confirmation invariably depends upon immunofluorescent observations. In addition to convention direct and indirect tests, the split-skin technique for antibody localisation has be-
Courses Dermatopathology - Update ElCOO1 Lymphoproliferative J. Conor O’Keane. Pathology University
College
Dublin,
disorders
Department, Ireland
Mater
Hospital,
Cutaneous lymphoproliferative disorders challenge many clinical and pathological concepts derived from lymphoproliferative disorders of lymph nodes. Cutaneous T cell lymphoma: Confounding variables include patient threshold for complaint, clinical threshold for biopsy and pathologic threshold for atypia. Many cases atypical clinically are also atypical histopathologically. Antigen deletion and T cell receptor gene rearrangements are identified in a number of inflammatory, as well as neoplastic dermatoses. Cutaneous B cell lymphoma is often secondary or the first manifestation of systemic B cell lymphoma. The concept of skin associated lymphoid tissue has some validity. Pseudolymphoma is a diagnosis which requires further definition analogous to a diagnosis of anaemia. CD30 positive lymphoproliferative disorders of skin include Hodgkin’s disease, lymphomatoid papulosis and large cell lymphoma. In contrast to systemic CD30 positive lymphoma, primary C30 positive skin lymphoma has a good prognosis if it occurs separately from mycosis fungoides. Summary: Modem diagnostic techniques still require careful clinicopathologic and light microscopic correlation to arrive at precise diagnosis. I COO2 Vasculitis: A differential diagnostic
approach
B. Zelger. Department Innsbruck,
Innsbruck,
of Dermatology, Austria
University
of
Vasculitides can present with a wide variety of clinicopathologic features. Using vasculitis allergica as a model a differential diagnostic approach of cutaneous and systemic vasculitides is presented. Vasculitis allergica is a common vasculitic problem of capillaries and postcapillary venules with an incidence of six patients per 100.000 people annually. Palpable purpura and leukocytoclastic vasculitis are the characteristic clinical and histological findings of this polyetiologic (infections, drugs, alimentary ingredients, connective tissue disorders, neoplasms) immunocomplex mediated disease. Unusual clinical presentations include urticarial vasculitis and erythema gyratum repens. Histologic peculiarities include the immunoglobulin A positive pupura Schonlein-Henoch as well as the fibrin thrombi rich variants of cryoglobulinemic (hepatitis C!) and hypergam-
maglobulinemic (plasmocytoma; connective tissue disorders) vasculitides. Moreover, in rare cases (~5%) vasculitis allergica can present in patients with more serious systemic arteritides such as Wegener’s granulomatosis (cANCA). Corticosteroids are in more than 90% of patients an effective curative therapy. Adverse outcome is mostly due to long term renal problems. I COO3 Histopathology Rino Cerio. England
of the alopecias
Dermatopathology can be helpful in the diagnosis of several scalp diseases but is often dependent on the quality of the biopsy. It may also have a role in the investigation into pathogenesis of disease. Follicular plugging, increased fibrous tracts as highlighted by elastic stains, and decreased anagen follicles are common to most patterns of alopecia. The introduction of transverse sectioning of scalp biopsies by Headington allows measurement of mean hair shaft diameter and the density of anagen follicles and follicular structures, all of which are diminished in androgenic alopecia. Accurate anagen/telogen counts are also available from this method. In active alopecia areata histology reveals lymphocytes surrounding catagen and anagen hair bulbs with at least 50% of follicles in catagemtelogen. The addition of immunofluorescence allows distinction between lichen planopilaris, discoid lupus erythematosus and cicatricial pemphigoid whilst the presence of massive lymphocyte-mediated apoptosis is present during the early stages of pseudopelade. Many cases of “thumbprint” scaring alopecia (clinical pseudopelade) are “burnt out” LP or DLE pathologically. The remainder heterogenous and often no cause is found. Hair-follicle hamartomas, metastic tumours, follicular mucinosis, scleroderma and granulomatous diseases are other conditions where histopathology plays a major part in the diagnosis of alopecia.
COO4 Differential diagnosis of auto-immune subepldermal blisters PH. McKee. St. Thomas’
Hospital,
London,
UK
Subepidermal blisters may be inflammatory or non-inflammatory The former commonly have an immunologically and frequently auto-immune mediated pathogenesis while the latter usually do not. There are however occasional exceptions to the rule. Inflammatory variants are often divided into neutrophilrich eosinophil-rich and lympho-histiocytic mixed categories. Histological assessment often points towards a specific diagnosis but confirmation invariably depends upon immunofluorescent observations. In addition to convention direct and indirect tests, the split-skin technique for antibody localisation has be-