Vitamin D-neutralizing CYP24A1 expression, oncogenic mutation states and histological findings of human papillary thyroid cancer.

OBJECTIVE: The aims of the present study were to examine gene and protein expression of the vitamin D-inactivating 24-hyroxylase (CYP24A1) and the activating 1-alpha-hydroxylase (CYP27B1) enzyme in human papillary thyroid cancer (PTC), furthermore, to investigate the association between CYP24A1 expression and numerous clinical, histological parameters and somatic oncogene mutation status of thyroid tumor tissues. MATERIALS AND METHODS: Gene expression analysis was carried out in 100 Hungarian thyroid samples, both normal and papillary tumor tissue sections of the same patient. The specific mRNA to the selected genes was analyzed by TaqMan probe-based quantitative real-time RT-PCR. The somatic oncogene mutation states of BRAF, NRAS, HRAS and KRAS were also tested. RESULTS: CYP24A1 mRNA expression was markedly increased in 52 cases (52%) of the examined papillary cancers compared with that of normal thyroid tissue. There was a tendency toward difference in the distribution of high-level CYP24A1 in the PTC accompanied with somatic oncogene mutation. Positive correlation was seen between increased CYP24A1 expression rate and a group of variables reflecting tumor malignity (mainly vascular invasion, lymph node metastasis, tumor size, hypothyreosis) by principal components analysis. No significant alteration was seen in CYP27B1 gene expression between neoplastic and normal tissues. CONCLUSIONS: A definite alteration was seen in vitamin D3-inactivating CYP24A1 gene activity in PTC compared to their normal tissues on a relatively large patient population. Our findings raise the possibility that CYP24A1 may also directly be involved in thyroid carcinogenesis.

Targeted phototherapy of plaque-type psoriasis using ultraviolet B-light-emitting diodes.

BACKGROUND: One of the major technological breakthroughs in the last decade is represented by the diversified medical applications of light-emitting diodes (LEDs). LEDs emitting in the ultraviolet (UV) B spectrum might serve as a more convenient alternative for targeted delivery of phototherapy in inflammatory skin diseases such as psoriasis. OBJECTIVES: We investigated the efficacy and safety of a new UVB-LED phototherapeutic device in chronic plaque-type psoriasis. METHODS: Twenty patients with stable plaque-type psoriasis were enrolled into a prospective, right-left comparative, open study. Symmetrical lesions located on extremities or trunk were chosen; one lesion was treated with the study device, whereas the other lesion served as an untreated control. Two treatment regimens were used in the study, one with an aggressive dose escalation similar to those used for outpatient treatment and one with slow increase in dose, similar to those used for treatment at home. RESULTS: Patients in both groups responded rapidly to the UVB-LED therapy. Early disease resolution was observed in 11 patients (seven in the first group and four in the second group). Overall improvement at end of therapy was 93% in the high-dose group and 84% in the low-dose group. Four patients from the high-dose group and five from the low-dose group were still in remission at the 6-month follow-up visit. CONCLUSIONS: These results suggest that this innovative UVB-LED device is effective in the treatment of localized psoriasis and may be useful in other UV-responsive skin diseases.

Regulatory T cells in atopic dermatitis: epidermal dendritic cell clusters may contribute to their local expansion.

BACKGROUND: Regulatory T cells (Tregs) have an essential role in tolerance and immune regulation. However, few and controversial data have been published to date on the role and number of these cells in atopic dermatitis (AD). OBJECTIVES: To investigate the number of CD4+CD25+FOXP3+ Tregs and interleukin 10-producing T regulatory type 1 (Tr1) cells in patients with AD. METHODS: Peripheral blood and skin biopsy samples from atopy patch test (APT)-positive patients with acute- and chronic-phase AD were investigated. Immunohistochemistry was applied to identify CD4+CD25+FOXP3+ Tregs in the skin, while flow cytometry was used to detect CD4+CD25highFOXP3+ Tregs and Tr1 cells in the peripheral blood. RESULTS: In the peripheral blood samples of patients with AD significantly elevated numbers of Tr1 cells were found. Although neither the absolute number nor the percentage of CD4+CD25highFOXP3+ Tregs showed significant alteration in the peripheral blood of patients, increased numbers of FOXP3+ Tregs were detected in skin biopsy specimens. All of the APT-positive skin samples showed epidermal dendritic cell aggregates, morphologically consistent with so-called Langerhans cell microgranulomas, which also contained intermingled FOXP3+ Tregs. CONCLUSIONS: Tr1 cell numbers were elevated in the peripheral blood and increased numbers of CD4+CD25highFOXP3+ Tregs were detected in the skin of patients with AD. The epidermal dendritic cell clusters in APT-positive lesional skin showed a close connection to the FOXP3+ Tregs.

Plasmoblastic lymphoma associated with human immunodeficiency virus.

Plasmoblastic lymphoma (PBL) is a subtype of the diffuse large B-cell lymphoma, typically present as extranodal disease associated with human immune deficiency virus (HIV) infection. PBLs are often the initial manifestation of AIDS. Here we present a case of PBL concerning the oral cavity. A 34-year-old woman presented a tumor in the oral cavity that involved the maxilla and gingiva (confirmed by CT-scan). The gingival biopsy showed a massive infiltration by large lymphoid cells with round, vesicular nuclei, prominent nucleoli, fine chromatin and an significant amount of basophilic cytoplasm which express CD79a, CD138, cytoplasmic lambda light chain and LCA, without staining for CD20, CD38, CD3 and CTK. Serological analysis confirmed HIV positivity. PBLs lack most B-lineage markers, but many express CD79a in at least some of the cells, therefore generate difficulties in differential diagnosis. Overall assessment and correlation of the histopathological and immunohistochemical features with the clinical findings and serology investigation are the most helpful diagnostic tools and can lead to the final diagnosis.

How we process trephine biopsy specimens: epoxy resin embedded bone marrow biopsies.

Improved cytomorphology of semithin resin sections over paraffin wax embedded sections may be important in diagnostic haematopathology. However, resin embedding can make immunohistochemical antigen detection or DNA isolation for clonal gene rearrangement assays difficult. This review describes the processing of bone marrow biopsies using buffered formaldehyde based fixation and epoxy resin embedding, with or without EDTA decalcification. Traditional semithin resin sections are completely rehydrated after etching in home made sodium methoxide solution. Resin elimination allows high resolution staining of tissue components with common histological stains. Efficient antigen retrieval and the Envision-HRP system permit the immunohistological detection of many antigens of diagnostic relevance, with retention of high quality cytomorphology. Furthermore, DNA can be extracted for clonality analysis. The technique can be completed within a similar time period to that of paraffin wax processing with only approximately 30% increase in cost. This technique has been used for diagnosis in over 4000 bone marrow biopsies over the past 14 years. By meeting traditional and contemporary demands on the haematopathologist, it offers a powerful alternative to paraffin wax processing for diagnosis and research.

Primary nodal marginal zone lymphomas of splenic and MALT type.

The existence of primary nodal marginal zone lymphomas (MZL) is controversial, as is their relationship to putative extranodal counterparts. Most nodal lymphomas with monocytoid B cell/marginal zone differentiation exhibit the morphologic and immunophenotypical characteristics of extranodal MALT-lymphomas. Splenic marginal zone lymphoma (SMZL) is also of putative marginal zone derivation, but it differs immunophenotypically from MALT lymphoma. To clarify the relationship between nodal and extranodal MZLs and to investigate the possible existence of a nodal variant of SMZL, 36 MZL initially considered to be primary nodal neoplasms were examined. Other low-grade lymphomas with marginal zone differentiation were excluded (small lymphocytic lymphoma/chronic lymphocytic leukemia [SLL/CLL], follicular lymphoma, and mantle cell lymphoma). Six nodal MZLs showed morphologic and phenotypic characteristics similar to those of SMZL, whereas 30 tumors were more similar to MALT-type lymphomas. The six tumors with SMZL features showed a polymorphic infiltrate surrounding residual germinal centers with absent or very attenuated mantle cuffs. These lymphomas were IgD positive (6/6) but cyclin D1 (0/5), CD5 (0/6), and CD23 (0/6) negative. Five of these patients came for treatment in stage I or II. No patient manifested splenomegaly, peripheral blood, and/or bone marrow infiltration either at diagnosis or during follow-up. Lymph nodes from 30 patients with MALT-type features showed a perisinusoidal and perivascular infiltration of monocytoid/centrocytoid cells and residual germinal centers with a relatively well-preserved mantle cuff. The neoplastic cells were negative for IgD (0/17), cyclin D1 (0/8), and CD5 (0/12). Seven of 16 (44%) patients with a detailed history and clinical follow-up had evidence of extranodal lymphoma. These observations suggest that most nodal B cell lymphomas with marginal zone differentiation are of the MALT type and that they are frequently associated with an extranodal component. In addition, a primary nodal counterpart of splenic MZL also exists, and may occur in the absence of splenomegaly.

An anti-CD3 epsilon serum detects T lymphocytes in paraffin-embedded pathological tissues in many animal species.

The in situ identification of T cells has been difficult and restricted to frozen tissue samples of a limited range of species. In this study, we demonstrate that an antiserum recognizing a phylogenetically conserved part of the CD3 epsilon cytoplasmic tail detects T cells of many avian and mammalian species in formalin-fixed paraffin-embedded tissue sections. This antiserum enables the morphological characterization of normal and pathological lymphoid tissues and lymphoid infiltrations in experimental work and in animal disease.

Histological and immunophenotypic profile of nasal NK/T cell lymphomas from Peru: high prevalence of p53 overexpression.

Nasal NK/T-cell lymphoma is a unique form of lymphoma highly associated with Epstein-Barr virus (EBV). These lymphomas are rare in Western populations and much more prevalent in some Asian and Latin American countries. Although there are several sizable studies from Asian countries, the same is not true from South America. The aim of this study was to analyze a series of 32 cases of nasal T-cell lymphoma from Peru and to further extend the characterization of this disease. Immunohistochemistry was performed on paraffin sections using the following antibodies: CD20 (L26), CD45RO, CD3, Ki67, CD57, CD56, TIA-1, bcl-2, and p53. The presence of EBV was investigated with immunohistochemical analysis for latent membrane protein (LMP)-1 and in situ hybridization using an antisense riboprobe to EBER 1. The 32 patients included 18 men and 14 women (M:F ratio, 1.2:1), with a median age of 43 years (11 to 72). Three categories were identified: (1) Nasal NK/T cell lymphomas (28 cases): The morphology ranged from small or medium-sized cells to large transformed cells. Necrosis was present in 86% of the cases, and angioinvasion was seen in 36% of the cases. All cases were positive for CD45RO, CD3, and for TIA-1. CD56 was positive in 21 of 27 cases (78%), and CD57 was negative in all cases. EBER 1 positivity was identified in most of the tumor cells in 27 of 28 cases (96%), including the six cases in which CD56 was negative. Overexpression of p53 was detected in 24 cases (86%). (2) Blastic NK cell lymphoma (1 case): The neoplastic cells resembled those of lymphoblastic lymphoma. CD56 and CD45RO were positive; TIA-1, TdT, and EBER-1 were negative. (3) Peripheral T-cell lymphoma (PTCL) unspecified (3 cases): CD56, TIA-1, and EBER-1 were negative. Nasal lymphomas from Peru with a T cell phenotype are predominantly EBV-associated NK/T cell lymphomas, similar to those described in Asian countries. The expression of CD56, TIA-1, and EBER-1, in combination, are very useful markers for the diagnosis of nasal NK/T cell lymphoma in paraffin-embedded tissue. The differential diagnosis of T-cell lymphomas in the nasal region should include rare cases of PTCL unspecified and the blastic variant of NK cell lymphoma. P53 is overexpressed in 86% of the cases. The significance of this finding with regard to clinical behavior and prognosis remains to be determined.

Subcutaneous panniculitic T-cell lymphoma is a tumor of cytotoxic T lymphocytes.

Subcutaneous panniculitic T cell lymphoma (SCPTCL) is characterized by primary involvement of the subcutaneous fat in a manner mimicking panniculitis. We studied 16 cases of this lymphoma to define its immunophenotypical profile as well as cellular origin. Involvement of the subcutaneous fat in a lacelike pattern with neoplastic cells rimming individual fat spaces was present in all cases. All 16 cases were of T cell phenotype. Thirteen of the 16 cases were CD8+, whereas three were negative for both CD4 and CD8. Twelve cases were stained for betaF1; of these, eight were betaF1+ and four were betaF1-. Focal staining for CD56 and CD30 was seen in 2 of 13 and two of eight cases, respectively. Intense diffuse positivity for the cytotoxic granular proteins T cell intracellular antigen-1 (TIA-1) and perforin was present in all cases, indicating an origin from cytotoxic T lymphocytes. Ten cases studied for Epstein-Barr viral sequences were negative. Eight of 9 cases with amplifiable DNA showed a clonal TCR gamma gene rearrangement by polymerase chain reaction. Controls included seven cases of benign panniculitis and seven other peripheral T cell lymphomas involving the skin and subcutaneous tissues: two peripheral T cell lymphomas, not otherwise specified (PTL,NOS), four anaplastic large cell lymphomas (ALCL), one T/NK cell lymphoma. The seven cases of panniculitis lacked cytological atypia and were characterized by an admixture of CD4+ and CD8+ cells with interspersed aggregates of L26+ B cells. Only infrequent cells showed staining for TIA-1 and perforin. In the control cases of T cell lymphoma, the infiltrate had a tendency for dermal and sometimes even epidermal involvement, with sheeting out of malignant cells, in contrast to the characteristic subcutaneous localization and rimming of fat spaces noted in SCPTCL. The two PTL, NOS were CD4+ and negative for both TIA-1 and perforin. Although the remaining controls expressed TIA-1 and perforin, in keeping with their cytotoxic T or natural killer (NK) cell origin, histological and other immunophenotypical features allowed distinction from SCPTCL. Five cases of SCPTCL were also stained for apoptosis using a tdt-mediated end labeling kit. All cases showed numerous positive apoptotic bodies, suggesting apoptosis as the mechanism of cell death in these tumors. Our study indicates that SCPTCL constitutes a distinctive clinicopathological entity derived from cytotoxic T lymphocytes and should be differentiated from other benign and malignant lymphoid infiltrates involving the subcutis. The apoptosis seen in these tumors may be mediated by release of cytotoxic granular proteins.

Extranodal peripheral T-cell and NK-cell neoplasms.

Mature or peripheral T-cell lymphomas are uncommon, accounting for only 10% to 15% of all non-Hodgkin lymphomas, and their classification has been controversial. In contrast to B-cell lymphomas, cytologic features have not been useful in defining disease entities, and cytologic grade has not been useful in predicting the clinical course. Similarly, many entities of T-cell or NK-cell derivation do not have a specific immunophenotype. Clinical features are of major importance, sometimes more important than the precise cell of orgin, in defining T-cell and NK-cell neoplasms. Most extranodal T-cell/NK-cell lymphomas have a cytotoxic phenotpye. The expression of cytotoxic molecules may predispose to apoptosis by tumor cells and normal bystander cells. Three major categories of extranodal T/NK cell tumors are nasal, intestinal, and subcutaneous panniculitis-like. Hepatosplenic gamma delta T-cell lymphoma is a more systemic disease derived from functionally immature cytotoxic cells. Many extranodal T-cell and NK-cell neoplasms are associated with Epstein-Barr virus (EBV); the association seems site dependent and shows some geographic variation. Tumors resembling any of the 3 prototypes may occur in a variety of extranodal sites. Extranodal T/NK cell lymphomas occur with increased frequency in the setting of immune suppression, especially after organ transplantation.

bc1-1 rearrangement and cyclin D1 protein expression in multiple lymphomatous polyposis.

Multiple lymphomatous polyposis (MLP), characterized by multiple polyps involving long segments of the gastrointestinal (GI) tract, is believed to represent GI involvement by mantle cell lymphoma (MCL), primarily based on its histologic and immunophenotypic similarities with MCL. However, rearrangement of the bcl-1 locus, the molecular lesion characteristic of MCL, has not been investigated in this group of patients. The authors evaluated the morphologic, immunophenotypic, and molecular features of 18 cases of MLP and 8 B-cell lymphomas involving the GI tract (including 6 MALT lymphomas). All MLP cases presented with GI disease, and were histologically similar to MCL. DNA extracted from formalin-fixed, paraffin-embedded tissue was analyzed for evidence of bcl-1 rearrangement by PCR, using chromosome 11 specific and consensus JH primers. Amplifiable DNA was obtained in 24 of 26 cases (16 of 18 MLP cases and 8 of 8 controls). bcl-1 rearrangement was detected in 6 of 16 cases (38%), subsequently confirmed by sequencing of the breakpoint region, and in 0 of 8 controls. Immunostaining for cyclin D1 was positive in 14 of 18 MLPs, including the 6 bcl-1 rearranged cases and negative in 6 of 6 evaluable controls. The detection of bcl-1 rearrangement and cyclin D1 expression in cases of MLP supports the view that MLP represents primary MCL, of the GI tract. These techniques may also be helpful in differentiating MLP from other GI lymphomas, particularly low grade lymphomas of MALT, when only small routinely fixed endoscopic biopsies are available.

Follicular dendritic cells in reactive and neoplastic lymphoid tissues: a reevaluation of staining patterns of CD21, CD23, and CD35 antibodies in paraffin sections after wet heat-induced epitope retrieval.

Structural alterations in the meshwork of follicular dendritic cells (FDCs) are frequently found in malignant lymphomas. Formaldehyde fixation and paraffin embedding, however, have long prevented consistent detection of FDCs. Wet heat-induced epitope retrieval in Dako Target Retrieval Solution (TRS) (pH 6.0) enabled the reliable detection of FDCs through CD21, CD23, and CD35 antigens in routinely processed tissues from 11 reactive and 69 neoplastic lymphoproliferations, thus allowing the distribution of the FDCs to be reevaluated. Germinal center FDCs in lymphoid hyperplasias and expanded FDC meshworks in the 8 mantle cell lymphomas, 7 low-grade MALT lymphomas, and 6 low-grade follicular lymphomas were intensely stained with all these markers. In 6 cases of B cell chronic lymphocytic leukemia, tumor cells were CD23+. In four cases of nodular lymphocyte predominance Hodgkin's disease (HD), expanded FDC meshwork's sharply delineating negative tumor cells and their rosetting T cell, were revealed mainly with the CD21 and CD35 antibodies. Follicular dendritic cells were also demonstrated in 11 cases of grade I nodular sclerosing HD, including follicular HD. Striking dendritic cell clusters were revealed with all 3 antibodies in 9 angioimmunoblastic T cell lymphomas. Sparse or no FDC meshworks were detected in the 4 cases of grade II nodular sclerosing HD, 5 follicular lymphomas with high-grade transformation, and 5 T cell-rich B cell lymphomas. CD35 immunostaining showed the most consistent labeling in the four FDC sarcomas studied in the current article. Reproducible demonstration of FDCs in routinely processed paraffin sections with CD21, CD23, and CD35 antibodies, as presented here, provides invaluable pieces of information in the diagnosis of lymphoproliferative disorders.

Bullous pyoderma gangrenosum as a manifestation of leukemia cutis.

The authors present the case of a 67-year-old patient in whom bullous pyoderma gangrenosum was the first symptom of acute myeloid leukemia. Histologically leukemic cells were found in the skin infiltrate, on the basis of which this lesion satisfied the criteria of leukemia cutis. It was underlined that in the background of such atypical bullous cases there are often hemoblastoses or their malignant transformation. Finally the connection between bullous pyoderma gangrenosum and atypical vesiculous Sweet syndrome is discussed.

Sarcoplasmic reticulum (SR) Ca2(+)-ATPase as a marker of muscle cell differentiation: immunohistochemical investigations of rhabdomyosarcomas and enhancement of the immunostaining after sodium methoxide pretreatment.

An immunocytochemical investigation of sarcoplasmic reticulum (SR) Ca2(+)-ATPase (SR-Ca-ATPase) was performed on formalin-fixed paraffin-embedded specimens of different types of rhabdomyosarcomas such as variants of embryonal and pleomorphic forms. Immunostaining frequency of tumours using SR-Ca-ATPase was compared with that of traditionally used muscle specific markers myoglobin, and desmin. Utilizing the possible cleaving of ester bounds sodium methoxide pretreatment was found to be very effective in enhancement of SR-Ca-ATPase immunostaining reaction. In 11 of 15 tissue specimens of 5 cases round shaped and elongated rhabdomyoblasts with definite cytoplasm exhibited positive immunoreactions with all of the polyclonal antibodies tested, using the streptavidin-biotinylated peroxidase complex (S-ABC-method). In formalin-fixed and paraffin-embedded material of 2 cases of undifferentiated rhabdomyosarcomas composed of small round tumour cells with scanty cytoplasm pretreatment with sodium methoxide induced the immunostaining of SR-Ca-ATPase. After that pretreatment a staining of the paranuclear cytoplasm occurred in many of these undifferentiated tumour cells. In these 2 cases, neither myoglobin nor desmin antibodies could react. However, when frozen sections of one of the poorly differentiated tumours were used monoclonal and polyclonal desmin antibodies reacted immunocytochemically in all of the small cells. Sodium methoxide induced or enhanced SR-Ca-ATPase immunocytochemical reaction can be a further addition to the diagnosis of rhabdomyosarcomas in formalin-fixed paraffin-embedded sections, even when desmin antibody fails to react.

[Leukemic neutrophilic dermatosis]. / Leukaemiás neutrophil dermatosis.

A case of a 67 year-old female patient with acute myeloid leukemia is presented. As the first manifestation of the disease, the patient had symptoms of Sweet's syndrome, later signs of gangrenous pyoderma have developed. This transient form is termed as a "leukemic neutrophilic dermatosis". The authors focus on the important diagnostic and prognostic value of this entity.

[Lymphoid infiltrates in the lung]. / A tüdö lymphoid infiltratumairól.

The authors reviewed material of 10 year period (1980-1990) of the Department of Pulmonology, Albert Szent-Györgyi University of Medicine, Deszk, Hungary, and selected 14 patients from the files who considered to belong in one of the lymphoproliferative conditions (4 low grade and 4 high grade lymphomas of B-cell type, 1 angiocentric, 1 mediastinal lymphoblastic non-Hodgkin's lymphoma, 3 Hodgkin's lymphoma cases and 1 pleural pseudolymphoma). Every patient admitted with prominent pulmonary symptoms. The diagnoses were based on histology and immunohistochemistry of tissue samples and autopsy. One high grade B-cell and the angiocentric malignant lymphoma proved to be primary pulmonary process. No specific radiomorphological signs were found, which could be characteristic for the pulmonary lympho-reticular infiltrations and also to distinct the primary and secondary ones. The lung infiltrations in the most of the non-Hodgkin's lymphoma cases with low grade malignancy appeared imitating tuberculosis, while the high grade group and Hodgkin's lymphomas displayed confusion with any primary or multiple tumors.

[Pathologic diagnosis of mantle cell lymphoma based on histologic, cytologic, immunohistologic and genetic characteristics]. / A köpenysejtes lymphoma patológiai diagnózisa hisztológiai, citológiai, immunhisztológiai és genetikai jellemzók alapján.

Mantle cell lymphoma (MCL) is a clinocopathologic entity representing a broad histologic and cytologic spectrum from cystic to the blastic form. The histologic, cytologic heterogeneity of MCLs may lead to diagnostic confusion. The aim of this study was to reclassify NHLs registered as centrocytic lymphoma and centrocytoid-centroblastoma by the Lymphoma Reference Centrum at the Department of Pathology, University Medical School of Pécs between 1988 and 1995. 63 of 67 selected cases have been classified as mantle cell lymphoma according to histological, cytological appearance, and the pheno- and genotype of tumour cells. 48% of the cases showed diffuse while 52% showed nodular histological pattern. 27% of diffuse MCLs composed of classic MCL cells (small to medium-size cells) 40% blastic and 33% both small and blastic lymphoma cells. In 76% of the nodular MCLs the tumour consisted of small to medium-size cells 15% blastic while 9% both small and blastic lymphoma cells. In 99% of MCL the diagnosis was supported by CD5, CD20 and CD23 positivity and in 67% by the presence of cyclin D1-overexpression. The t(11;14) chromosome translocation PCR amplification was positive in 3 of 17 cases investigated. The authors conclude that MCLs represent a heterogeneous disease based on the cytology of the tumour cells. The nodular architecture was associated with classic MCL cells while the diffuse form was more frequently associated with blastic or combined cytological appearance. The correct diagnosis of MCL could be reached by tumour cell immunophenotyping, while molecular genetic methods proved to be informative only in part of the cases studied.

[Langerhans cell granulomatosis of the lung (morphological studies of lung biopsy specimens from patient with histiocytosis X]. / A tüdó Langerhans-sejtes granulomatosisa (morfológiai vizsgálatok histiocytosis X-ben szenvedö betegekból származó tüdóbiopsiás anyagokon).

Morphologic studies, including conventional histology, electronmicroscopy and immunohistochemistry were performed on biopsies from 5 patients with pulmonary Langerhans's cell granulomatosis (LCG). In all cases we were able to identify the CD la antigen on paraffin section supporting the diagnosis of LCG.

[Primary cerebral T-cell lymphoma]. / Elsödleges agyi T-sejt-lymphoma.

The authors describe a case of primary cerebral T-cell lymphoma observed in a 68-year-old man. The patient suffered from disseminated follicular carcinoma of the thyroid and the clinical picture has been dominated by neurological symptoms of presumed metastatic origin. Primary cerebral lymphoma was discovered at autopsy. Histologically, it proved to be a high-grade malignant pleomorphic non Hodgkin's lymphoma whose T-cell lineage was confirmed by immunohistochemistry. The patient did not manifest any congenital or acquired immune deficiency. There were neither cerebral metastases of the thyroid cancer nor any evidence for extracranial involvement by a lymphoma. Providing a brief literature review of cerebral T-cell lymphomas, the authors discuss some major traits of this exceptional form of lymphoid neoplasia of the central nervous system. Differential diagnostic and theoretical implications raised by cerebral lymphomas as second malignant tumors synchronously or metachronously associated with other malignant diseases are envisaged.