[Extranodal manifestation of classical Hodgkin lymphoma in the head and neck region]. / Extranodale Manifestation klassischer Hodgkin-Lymphome im HNO-Bereich.

BACKGROUND: Extranodal lymphomas occurring in the head and neck region account for 12-15% of all malignant tumors of this locality. Classical Hodgkin lymphoma (cHL) is a rare subtype, representing around 1% of all lymphomas in Waldeyer's ring. Cases diagnosed in the Reference Centre for Lymph Node Pathology at the Pathological Institute of the University of Würzburg were further analyzed in this study. MATERIALS AND METHODS: Histological subtype and EBV association of 21 cases were reviewed in conjunction with clinical data. RESULTS: Data of 12 male and 9 female patients with an average age of 51 years (median 45; 35-72) were reviewed. All samples were taken from the lymphatic tissue of the Waldeyer's ring (nasopharynx n = 15, palatine tonsils n = 5, lingual tonsils n = 1). The most common symptoms leading to a consultation with an otorhinolaryngologist were otalgia, swelling, or impaired nasal breathing. Only four patients showed typical B­symptoms. In 6 cases (29%), an isolated extranodal manifestation was found, 15 patients (71%) showed simultaneous infiltration of cervical lymph nodes during staging, and 6 cases (29%) were EBV positive. CONCLUSION: An exclusively extranodal manifestation of cHL in Waldeyer's ring is rare, whereas infiltration of extranodal tissue in the case of a primary manifestation of lymphoma in cervical nodes can occur more frequently and may often remain undiagnosed. Therefore, a specialized ENT consultation could be a reasonable complementary module in tumor staging to determine the correct tumor extent.

[Ten years of telepathology for a mission hospital in Tanzania]. / 10 Jahre Telepathologie für ein Missionskrankenhaus in Tansania.

BACKGROUND: A collaboration between a hospital in Tanzania and a German institute for pathology was initiated in 2007 with the aim of establishing a working telepathological connection using the internet-based platform iPath to transmit static histological images. OBJECTIVES: This study aimed to describe the diagnostic spectrum evaluated in the course of an aid project in a developing country in Africa. MATERIAL AND METHODS: A total of 5230 diagnoses were analyzed, including cases that could only be definitively concluded after a second analysis of the paraffin-embedded material in Germany. The most frequent diagnoses in the five largest diagnostic groups from 17 different anatomical locations were surveyed. In addition, cases sampled from children/young adults and rare diagnoses were assessed separately. RESULTS: Altogether we diagnosed 2934 (56.1%) benign and 2134 (40.8%) malignant diseases. The number of cases sent to Germany for a second opinion was 734 (14%). The five most common anatomical locations were the uterine cervix (n = 1211), the prostate (n = 728), skin (n = 626), breast (n = 524), and lymph nodes (n = 340). Children comprised 504 cases (9.6%). Typical tropical diseases were only rarely seen in the whole collective of cases. CONCLUSIONS: By means of telepathology histopathological diagnoses can be supplied in a short period of time. Difficulties occurred mainly due to the unstable staff situation on site and because the quality of sampled biopsy material was not always sufficient for further investigations. Furthermore, it became clear in the course of this aid project that a predominance of standard diagnostic findings routinely seen in the pathology of tumors and infections can be anticipated rather than exotic diseases.

Stromal gene signatures in large-B-cell lymphomas.

BACKGROUND: The addition of rituximab to combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), or R-CHOP, has significantly improved the survival of patients with diffuse large-B-cell lymphoma. Whether gene-expression signatures correlate with survival after treatment of diffuse large-B-cell lymphoma is unclear. METHODS: We profiled gene expression in pretreatment biopsy specimens from 181 patients with diffuse large-B-cell lymphoma who received CHOP and 233 patients with this disease who received R-CHOP. A multivariate gene-expression-based survival-predictor model derived from a training group was tested in a validation group. RESULTS: A multivariate model created from three gene-expression signatures--termed "germinal-center B-cell," "stromal-1," and "stromal-2"--predicted survival both in patients who received CHOP and patients who received R-CHOP. The prognostically favorable stromal-1 signature reflected extracellular-matrix deposition and histiocytic infiltration. By contrast, the prognostically unfavorable stromal-2 signature reflected tumor blood-vessel density. CONCLUSIONS: Survival after treatment of diffuse large-B-cell lymphoma is influenced by differences in immune cells, fibrosis, and angiogenesis in the tumor microenvironment.

A human recombinant autoantibody-based immunotoxin specific for the fetal acetylcholine receptor inhibits rhabdomyosarcoma growth in vitro and in a murine transplantation model.

Rhabdomyosarcoma (RMS) is the most common malignant soft tissue tumor in children and is highly resistant to all forms of treatment currently available once metastasis or relapse has commenced. As it has recently been determined that the acetylcholine receptor (AChR) gamma-subunit, which defines the fetal AChR (fAChR) isoform, is almost exclusively expressed in RMS post partum, we recombinantly fused a single chain variable fragment (scFv) derived from a fully human anti-fAChR Fab-fragment to Pseudomonas exotoxin A to generate an anti-fAChR immunotoxin (scFv35-ETA). While scFv35-ETA had no damaging effect on fAChR-negative control cell lines, it killed human embryonic and alveolar RMS cell lines in vitro and delayed RMS development in a murine transplantation model. These results indicate that scFv35-ETA may be a valuable new therapeutic tool as well as a relevant step towards the development of a fully human immunotoxin directed against RMS. Moreover, as approximately 20% of metastatic malignant melanomas (MMs) display rhabdoid features including the expression of fAChR, the immunotoxin we developed may also prove to be of significant use in the treatment of these more common and most often fatal neoplasms.

A20 deletion is associated with copy number gain at the TNFA/B/C locus and occurs preferentially in translocation-negative MALT lymphoma of the ocular adnexa and salivary glands.

The genetic basis of MALT lymphoma is largely unknown. Characteristic chromosomal translocations are frequently associated with gastric and pulmonary cases, but are rare at other sites. We compared the genetic profiles of 33 ocular adnexal and 25 pulmonary MALT lymphomas by 1 Mb array-comparative genomic hybridization (CGH) and revealed recurrent 6q23 losses and 6p21.2-6p22.1 gains exclusive to ocular cases. High-resolution chromosome 6 tile-path array-CGH identified NF-kappaB inhibitor A20 as the target of 6q23.3 deletion and TNFA/B/C locus as a putative target of 6p21.2-22.1 gain. Interphase fluorescence in situ hybridization showed that A20 deletion occurred in MALT lymphoma of the ocular adnexa (8/42=19%), salivary gland (2/24=8%), thyroid (1/9=11%) and liver (1/2), but not in the lung (26), stomach (45) and skin (13). Homozygous deletion was observed in three cases. A20 deletion and TNFA/B/C gain were significantly associated (p<0.001) and exclusively found in cases without characteristic translocation. In ocular cases, A20 deletion was associated with concurrent involvement of different adnexal tissues or extraocular sites at diagnosis (p=0.007), a higher proportion of relapse (67% versus 37%) and a shorter relapse-free survival (p=0.033). A20 deletion and gain at TNFA/B/C locus may thus play an important role in the development of translocation-negative MALT lymphoma.

The PTPN22gain-of-function+1858T(+) genotypes correlate with low IL-2 expression in thymomas and predispose to myasthenia gravis.

Protein tyrosine phosphatase, non-receptor type 22 (PTPN22) inhibits T-cell activation and interleukin-2 (IL-2) production. The PTPN22(gain-of-function)+1858T(+) genotypes predispose to multiple autoimmune diseases, including early-onset (non-thymomatous) myasthenia gravis (MG). The disease association and the requirement of IL-2/IL-2 receptor signaling for intrathymic, negative T-cell selection have suggested that these genotypes may weaken T-cell receptor (TCR) signaling and impair the deletion of autoreactive T cells. Evidence for this hypothesis is missing. Thymoma-associated MG, which depends on intratumorous generation and export of mature autoreactive CD4(+) T cells, is a model of autoimmunity because of central tolerance failure. Here, we analyzed the PTPN22 +1858C/T single nucleotide polymorphism in 426 German Caucasian individuals, including 125 thymoma patients (79 with MG), and investigated intratumorous IL-2 expression levels. Unlike two previous studies on French and Swedish patients, we found strong association of PTPN22 +1858T(+) genotypes not only with early-onset MG (P=0.00034) but also with thymoma-associated MG (P=0.0028). IL-2 expression in thymomas with PTPN22 +1858T(+) genotypes (P=0.028) was lower, implying weaker TCR signaling. We conclude that the PTPN22(gain-of-function) variant biases towards MG in a subgroup of thymoma patients possibly by impeding central tolerance induction.

Gastric extranodal marginal zone B-cell lymphomas of MALT type exclusively express Toll-like receptor 4 in contrast to other lymphomas infiltrating the stomach.

BACKGROUND: Development and growth of extranodal marginal zone B-cell lymphomas (eMZBCLs) of mucosa-associated lymphoid tissue (MALT) type are thought to be highly dependent on Helicobacter pylori and autoantigens. Receptors mediating these effects are not characterised so far. Toll-like receptors (TLRs) recognise bacterial proteins and autoantigens, which results in inflammatory reactions and influences tumour development and growth. MATERIALS AND METHODS: TLR4, 5 and 9 expressions were evaluated by immunohistology and confocal microscopy in gastric eMZBCL in comparison to other lymphomas infiltrating the stomach. RESULTS: TLR4 was exclusively expressed on the cell surface in all eMZBCL (n = 19) and not in chronic lymphocytic leukaemia (CLL, n = 12) or mantle cell lymphoma (MCL, n = 10). TLR5 was strongly expressed in CLL and weak in some eMZBCL (15 of 19), but not in MCL. TLR4, 5 and 9 were negative in all the three lymphoma entities. CONCLUSIONS: Exclusive TLR4 expression may enable eMZBCL to interact with H. pylori and autoantigens. Blockade of TLR4 might be a new approach for therapy of eMZBCL of MALT type.

Triggering receptor expressed on myeloid cells-1 (TREM-1) expression on gastric epithelium: implication for a role of TREM-1 in Helicobacter pylori infection.

In Helicobacter pylori gastritis gastric epithelium plays a central role in the innate immunity to H. pylori. However, epithelial receptors interacting with H. pylori have been poorly characterized so far. Recently a new triggering receptor expressed on myeloid cells-1 (TREM-1) has been identified on human neutrophils and monocytes. On these cells TREM-1 triggers innate immunity by stimulating the secretion of interleukin (IL)-8 and tumour necrosis factor (TNF)-alpha and thus amplifies bacterial-induced inflammation. In this study expression and function of TREM-1 in gastric epithelium exposed to H. pylori has been investigated. TREM-1 mRNA and protein were expressed on gastric epithelial cell lines as demonstrated by reverse transcription-polymerase chain reaction (RT-PCR) and fluorescence activated cell sorter analysis. Gastric epithelial TREM-1 expression was up-regulated directly by H. pylori and was independent of epithelial IL-8 induced by H. pylori. Immunohistochemistry and tissue RT-PCR demonstrated significantly stronger TREM-1 expression in H. pylori gastritis compared with the non-inflamed gastric mucosa supporting in vivo that epithelial TREM-1 is up-regulated during H. pylori infection. Stimulation of gastric epithelial TREM-1 receptor resulted in IL-8 up-regulation on mRNA and protein level, as shown by real-time PCR and immunoassay. This is the first study localizing TREM-1 on gastric epithelium. Functional data suggest that TREM-1 expressed on gastric epithelium amplifies inflammation of the underlying gastric mucosa by up-regulation of IL-8.

Is sclerosing angiomatoid nodular transformation (SANT) of the splenic red pulp identical to inflammatory pseudotumour? Report of 16 cases.

AIMS: To report 16 cases of sclerosing angiomatoid nodular transformation (SANT) of the splenic red pulp. METHODS AND RESULTS: Patients were selected in two phases. An initial group of seven patients was diagnosed with SANT based on the presence of angiomatoid nodules. Sheets of inflammatory fibrosis were found in three patients, resembling inflammatory pseudotumour (IPT); nine further cases of IPT were reviewed. Angiomatoid nodules were detected, leading to the diagnosis of SANT in all cases. The splenic mass (10-150 mm in diameter) was polycyclic, composed of multiple small nodules of loose connective tissue comprising myofibroblasts and a dense network of capillaries as well as some remnants of sinuses. Collagenous fibrosis surrounded them. Bands or large sheets of fibrosis, infiltrated by various inflammatory cells, particularly polytypic plasmacytes, resembling IPT, were present in 10 cases. CONCLUSIONS: SANT of the red pulp is a distinct benign pseudotumorous lesion of the spleen characterized by the presence of angiomatoid nodules. We observed such angiomatoid nodules in all our cases of splenic IPT, which were not follicular dendritic cell or myofibroblastic tumours. We therefore recommend careful examination for angiomatoid nodules in all suspected cases of splenic IPT.

Distinctive patterns of BCL6 molecular alterations and their functional consequences in different subgroups of diffuse large B-cell lymphoma.

Gene expression profiling of diffuse large B-cell lymphoma (DLBCL) has revealed biologically and prognostically distinct subgroups: germinal center B-cell-like (GCB), activated B-cell-like (ABC) and primary mediastinal (PM) DLBCL. The BCL6 gene is often translocated and/or mutated in DLBCL. Therefore, we examined the BCL6 molecular alterations in these DLBCL subgroups, and their impact on BCL6 expression and BCL6 target gene repression. BCL6 translocations at the major breakpoint region (MBR) were detected in 25 (18.8%) of 133 DLBCL cases, with a higher frequency in the PM (33%) and ABC (24%) subgroups than in the GCB (10%) subgroup. Translocations at the alternative breakpoint region (ABR) were detected in five (6.4%) of 78 DLBCL cases, with three cases in ABC and one case each in the GCB and the unclassifiable subgroups. The translocated cases involved IgH and non-IgH partners in about equal frequency and were not associated with different levels of BCL6 mRNA and protein expression. BCL6 mutations were detected in 61% of DLBCL cases, with a significantly higher frequency in the GCB and PM subgroups (>70%) than in the ABC subgroup (44%). Exon-1 mutations were mostly observed in the GCB subgroup. The repression of known BCL6 target genes correlated with the level of BCL6 mRNA and protein expression in GCB and ABC subgroups but not with BCL6 translocation and intronic mutations. No clear inverse correlation between BCL6 expression and p53 expression was observed. Patients with higher BCL6 mRNA or protein expression had a significantly better overall survival. The biological role of BCL6 in translocated cases where repression of known target genes is not demonstrated is intriguing and warrants further investigation.

Cutaneous dissemination of nasal NK/T-cell lymphoma in a young girl.

In Europe and the USA, the incidence of primary nasal natural killer (NK)/T-cell lymphoma is rare. The skin is one of the predilection sites for dissemination. Cutaneous dissemination is a poor prognostic sign and is consistently fatal. We describe the case of a 17-year-old white German girl with a primary nasal NK/T-cell lymphoma and cutaneous dissemination. She presented with multiple maculopapular patches involving the trunk and thighs, and a 4-week history of headache, fever and fatigue. Biopsies of the skin and the nasal mucosa were taken. Pathological examination of both specimens revealed a NK/T-cell lymphoma. Epstein-Barr virus RNA was detected in the lymphoma cells by in situ hybridization. Unfortunately, the patient died of disease within 1 week.

[Pathogenesis and morphology of hemophagocytic syndrome in the spleen]. / Pathogenese und Morphologie des hämophagozytischen Syndroms in der Milz.

Hemophagocytic syndrome (macrophage activation syndrome) is a group of disorders characterized by clinical, histological and biological symptoms of T-lymphocytes/NK cell-driven macrophage stimulation with subsequent hemophagocytosis which can be observed in various organs, particularly in the bone marrow and spleen. The main clinical symptoms include cytopenia, multiple organ dysfunction, fever unresponsive to antibiotics, hepatosplenomegaly and rash. Besides rare inherited immune system anomalies (primary hemophagocytic syndrome), the most prevalent etiologies of hemophagocytic syndrome are infections (viral, bacterial and parasitic), cancers, lymphoproliferative disorders and systemic diseases. Hemophagocytic syndrome is treated with immunosuppressives, cytostatic drugs, plasmapheresis and intravenous immunoglobulins/anti-TNF antibodies and due to the multiorgan involvement and the associated high mortality, recognition of early serum changes, such as very high levels of ferritin is mandatory. The most relevant histological changes are the increase of histiocytes showing evidence of phagocytosis of erythroid cells, platelets and granulocytes as well as in the spleen a rarefaction of the white pulpa with lack of lymph follicles and abundant lymphocytes, plasma cells and plasma cell precursors in the pulpa cords.

[Splenic marginal zone B cell lymphomas]. / Splenische Marginalzonen-B-Zell-Lymphome.

Splenic marginal zone B cell lymphomas (SMZBCL) are rare, organotypic, lymphoid neoplasms with distinct clinicopathological features. At initial presentation, the spleen, bone marrow and peripheral blood are usually involved, while generalized lymphadenopathy is only rarely observed. Molecularly, somatic hypermutation of IgVH genes can be detected in roughly half of the cases, and deletions in 7q are present in 45% of tumors. Approximately 10%-15% of SMZBCL do occur in the setting of chronic hepatitis C. This association underlines the importance of antigenic stimulation in the proliferation of the tumor cells in HCV-associated SMBCL, if not also in their classical counterparts. More recently, gene profiling studies using cDNA microarrays revealed a homogeneous expression profile in SMZBCL, thus further confirming the notion of a distinct tumor entity. The clinical course is indolent in the majority of cases; however, some patients follow a more aggressive clinical course, usually associated with some particular molecular features in these tumors, such as unmutated IgVH genes and 7q deletions.

[Splenic vascular disturbances]. / Kreislaufstörungen der Milz.

Splenic vascular disturbances mainly affect the red pulp and can involve the venous or arterial blood flow. The venous blood flow may be impaired by congestion and morphologically shows dilated splenic sinuses. Disturbances of the arterial blood flow may occur in connection with anomalies of the erythrocyte membrane or in immune haemolysis and usually are characterized by narrow splenic sinuses. Infarction of the spleen is usually caused by arterial embolism.

[Vascular proliferations of the spleen]. / Vaskuläre Tumoren der Milz.

Vascular proliferations of the spleen reflect the variability of vascular structures occurring in the normal spleen. Besides haemangiomas, there is a spleen-specific vascular neoplasm, littoral cell angioma, that often occurs as a paraneoplastic lesion and thus may require the differential diagnostic delineation of metastases to the spleen in patients with known neoplasms. The most common malignant vascular tumours of the spleen are angiosarcomas. A recently described vascular lesion of unknown pathogenesis, sclerosing angiomatoid nodular transformation (SANT) of the spleen, usually is an incidental finding detected in the course of imaging studies.

[Functional splenic pathology and differential diagnosis in splenectomy]. / Funktionelle Pathologie der Milz. Grundlagen und differenzialdiagnostische Erwägungen am Milzpräparat.

From a pathologic-anatomic perspective, the splenic parenchyma is divided into red and white pulp, which react to a certain extent independently from one another in the context of systemic and local processes. While the red pulp serves to filter blood, the white pulp, together with the perifollicular marginal zone, organizes immune reactions. In the marginal zone, innate and acquired immune responses are integrated. The vast majority of splenectomies serve therapeutic purposes in the context of already known disease. Therefore, only about 10% of splenectomy specimens are diagnostic challenges, including the diagnosis of haematological diseases, splenomegaly or splenic tumors. Differential diagnosis considerations are discussed based on the clinical presentation.

[Inflammatory reactions of the spleen]. / Entzündliche Reaktionstypen der Milz.

Inflammatory reactions of the spleen occur in the context of two pathophysiological settings. First, lymphoid hyperplasia of the spleen can be the result of a principally physiological production of immune effector cells e.g. due to systemic viral infections, autoimmune diseases and acquired or inherited immunodeficiencies. Second, the spleen itself may be the target of a pathological inflammatory reaction; this setting is exemplified by abscess formation due to septicopyemic spread of bacteria and by granulomatous inflammations, e.g. due to tuberculosis or sarcoidosis. Differential diagnostic considerations have to include splenic inflammatory pseudotumors, mycobacterial spindle cell tumors and lymphomas with granulomatous or histiocyte-rich reactive changes.

[The spectrum of microbiological agents causing pulmonary MALT-type lymphomas. A 16S rRNA-based analysis of microbial diversity]. / Das Erregerspektrum pulmonaler MALT-Typ-Lymphome. Eine 16S-rRNA-basierte Analyse der mikrobiellen Diversität.

For several anatomical localisations of extranodal marginal zone B-cell lymphoma of MALT type (eMZBCL), an association with chronic inflammation caused by microbiological agents (e.g. Helicobacter pylori in the stomach) has been described. In the lung, a link between lymphomagenesis and a defined causative organism is still missing. A comprehensive diversity survey using 16S-rDNA library construction followed by restriction fragment length polymorphism (RFLP) analysis, sequencing, and phylogenetic tree construction was employed for nine cases each of BALT lymphoma and control lung tissues (normal foetal lung, pneumonitis, carcinoid). This highly sensitive method, hereafter termed SHARP screening allowed for identification of the entire bacterial population in the tissue in a cultivation-independent manner. It was noteworthy that in eight of the nine cases of BALT lymphoma, bacteria of the Alcaligenaceae family (Alcaligenes, Achromobacter, AKIW733), were detected, whereas none of the control cases showed the presence of these clades. 16S-rDNA library construction in combination with RFLP screening and phylogenetic analyses, hereafter described as SHARP screening, is a cultivation-independent tool for analysing the microbial environment in chronic inflammation processes giving rise to extranodal marginal zone B-cell lymphomas of MALT-type. Betaproteobacteria of the Alcaligenaceae family may be affiliated with and possibly involved in the lymphomagenesis of BALT lymphomas.

[Lymphomas of the spleen]. / Lymphome der Milz.

The spleen is commonly affected by malignant lymphomas and the macroscopic findings of the spleen correlate with different lymphoma entities. However, most lymphomas are not primarily diagnosed in splenectomy specimens. Exceptions include splenic marginal zone lymphomas and hepatosplenic T-cell lymphomas that are typically diagnosed from histological findings. In addition, hairy-cell leukemia, LGL leukemia and T-cell prolymphocytic leukemia typically show characteristic patterns of infiltration in the spleen which may be diagnostically useful. The different infiltration patterns of these tumors are discussed here.

Thymus in myasthenia gravis. Isolation of T-lymphocyte lines specific for the nicotinic acetylcholine receptor from thymuses of myasthenic patients.

The thymus is believed to play a central role in the pathogenesis of Myasthenia gravis (MG). According to a previous hypothesis, MG is initiated within the thymus by immunogenic presentation of locally produced nicotinic acetylcholine receptor (AChR) to potentially autoimmune T cells. Data of 10 consecutive MG patients demonstrate two critical features of MG thymuses that support the concept of intrathymic activation of autoreactive, AChR-specific lymphocytes. Morphologically, the thymuses showed lympho-follicular hyperplasia in nine cases and benign thymoma in one case. The paramount feature revealed by immunohistological double marker analyses was the intimate association of myoid cells (antigen producing) with interdigitating reticulum cells (potentially antigen presenting cells), both of which were surrounded by T3+ lymphocytes in thymus medulla. All 10 thymuses contained T lymphocytes reactive with AChR. This was in contrast to the peripheral immune compartment (blood) where in only 3 of 10 patients, significant T cell responses to AChR were observed. AChR-specific T cell lines could be established from 8 of 10 thymuses, all members of the helper/inducer subset as indicated by the expression of markers T3 and T4.