Renal cancer and pneumothorax risk in Birt-Hogg-Dubé syndrome; an analysis of 115 FLCN mutation carriers from 35 BHD families.

BACKGROUND: Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant condition caused by germline FLCN mutations, and characterised by fibrofolliculomas, pneumothorax and renal cancer. The renal cancer risk, cancer phenotype and pneumothorax risk of BHD have not yet been fully clarified. The main focus of this study was to assess the risk of renal cancer, the histological subtypes of renal tumours and the pneumothorax risk in BHD. METHODS: In this study we present the clinical data of 115 FLCN mutation carriers from 35 BHD families. RESULTS: Among 14 FLCN mutation carriers who developed renal cancer 7 were <50 years at onset and/or had multifocal/bilateral tumours. Five symptomatic patients developed metastatic disease. Two early-stage cases were diagnosed by surveillance. The majority of tumours showed characteristics of both eosinophilic variants of clear cell and chromophobe carcinoma. The estimated penetrance for renal cancer and pneumothorax was 16% (95% minimal confidence interval: 6-26%) and 29% (95% minimal confidence interval: 9-49%) at 70 years of age, respectively. The most frequent diagnosis in families without identified FLCN mutations was familial multiple discoid fibromas. CONCLUSION: We confirmed a high yield of FLCN mutations in clinically defined BHD families, we found a substantially increased lifetime risk of renal cancer of 16% for FLCN mutation carriers. The tumours were metastatic in 5 out of 14 patients and tumour histology was not specific for BHD. We found a pneumothorax risk of 29%. We discuss the implications of our findings for diagnosis and management of BHD.

[The immune system of the skin and stereotyped reaction patterns in inflammatory skin diseases]. / Het immuunsysteem van de huid en stereotiepe reactiepatronen bij inflammatoire huidziekten.

The clinical and histological presentation of inflammatory disease in the skin is exceedingly heterogeneous. Nonetheless, most inflammatory dermatoses can be classified according to five stereotypical tissue-reaction patterns: the spongiotic, the lichenoid, the psoriasiform, the vesiculo-bullous and the vasculopathic. By means of potent antigen-presenting cells, cytokine and chemokine cascades and a skin-specific cutaneous lymphocyte antigen (CLA)-positive lymphocyte population, the skin is able to respond very efficiently to pathogens that threaten the individual. Inflammatory skin diseases follow the rules and routes of the physiological reaction to inflammation but however for various reasons the immune response may be inadequate, enhanced or chronic. In allergic contact dermatitis, which is a prototype of the spongiotic reaction pattern, the inflammation is directed against an otherwise harmless antigen, for which the body is sensibilized. Lichenoid dermatitis (like erythema multiforme, graft versus host disease or lupus erythematodes) is based on a primary cytotoxic reaction against the basal epithelial cell, due to alterations in its antigenic make-up or due to an altered immune response. In psoriasis, an example of psoriasiform dermatitis, the interaction between inflammatory cells, antigen presenting cells and epithelial cells is disturbed.

[Three patients with a Spitz naevus that later turned out to be a melanoma]. / Drie patiënten met op Spitz-naevus gelijkende afwijkingen die later een melanoom bleken te zijn.

A melanocytic lesion was removed from each of three patients: 2 men aged 37 and 65 and 1 woman aged 45. The preferred diagnosis was 'Spitz naevus'. Subsequently, all three developed regional (sub)cutaneous and/or lymph node metastases, indicating that the lesions were melanomas. The histopathological distinction between Spitz naevus and melanoma is often very difficult. Classical Spitz naevi can be diagnosed correctly only if the entire lesion is available for histological examination. Incompletely removed lesions should be re-excised for further examination. Some melanomas resemble Spitz naevi, but can be recognised on the basis of well-defined histological indicators of malignancy. Some melanocytic lesions, however, cannot be categorised with confidence as being either benign (Spitz naevus) or malignant (spitzoid melanoma). Thus, a group of lesions with inconclusive histology remains and has been designated as 'atypical Spitz tumour' or 'Spitz tumour of uncertain malignant potential'. Generally, such lesions are best treated as melanomas.

Metastasectomy and active specific immunotherapy for a large single melanoma metastasis.

A patient with a large duodenal melanoma metastasis, involving adjacent jejunum and colon, is presented. Treatment consisted of a combination of radical surgery and active specific immunotherapy by means of an autologous tumor cell vaccine and BCG after which a recurrence-free survival of now more than 10 years has been observed. The role of surgery and immunotherapy in the treatment of metastatic melanoma are discussed.

All infiltrating T-lymphocytes in Hodgkin's disease express immunohistochemically detectable T-cell receptor zeta-chains in situ.

AIM: We studied the expression of TCR zeta-chain on tumour-infiltrating lymphocytes in EBV-positive and EBV-negative cases of Hodgkin's disease (HD), to assess whether downregulation of TCR zeta-chain on tumour-infiltrating lymphocytes might be a mechanism for immune escape of the neoplastic cells. METHODS AND RESULTS: By immunohistochemistry we investigated tissue of 27 cases of primary HD, both paraffin embedded and frozen, for the presence of T-cell receptor complex zeta-chain and other T-cell markers on the reactive cells. Strong membranous staining of TCR zeta-chain was present in all cases in frozen tissue. In contrast, in paraffin-embedded material substantial loss of TCR zeta-chain was detected in old (> 6 years) tissues. However, no differences in either the number of positive cells or their staining intensity were observed in EBV-positive and negative cases of HD as detected in frozen tissue. Storage of paraffin-embedded tissue leads to a rapid and substantial loss of TCR zeta-chain reactivity compared to frozen material of the same HD cases. Staining reactivity of other T-cell markers (CD3, CD4 and CD8) on paraffin-embedded material remained unaffected. Immunofluorescent double-staining confirmed colocalization and coexpression of TCR zeta-chain and CD3. CONCLUSIONS: In frozen biopsies of primary HD TCR zeta-chain was expressed on all reactive CD3-positive cells, both in EBV-positive and EBV-negative cases. This suggests that zeta-chain downregulation is not a likely mechanism whereby neoplastic cells of HD can escape immune surveillance.

A new monoclonal antibody (3A5) that recognises a fixative resistant epitope on tissue macrophages and monocytes.

AIMS: To develop a monoclonal antibody specific for human macrophages in routinely processed material. METHODS: The monoclonal antibody was derived from a mouse popliteal lymph node after subcutaneous immunisation in the footpad with fragments of human spleen depleted of lymphocytes and erythrocytes. RESULTS: 3A5 is a monoclonal antibody reactive with macrophages, monocytes, and histiocytes in routinely processed (formalin fixed, paraffin wax embedded) human tissue specimens. Unlike the well known panmacrophage marker KP1 (CD68), neither dendritic cells (interdigitating cells, Langerhans' cells, and microglia) nor myeloid, lymphoid, or epithelial cells stained with 3A5. CONCLUSION: As the staining pattern of 3A5 is restricted, compared with other macrophage markers and the recognised epitope survives common fixation and embedding procedures, 3A5 is a valuable marker for histiocytes and macrophages in routine diagnostic applications.