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Immune cell infiltrates have proven highly relevant for colorectal carcinoma prognosis, making colorectal cancer a promising candidate for immunotherapy. Because tumors interact with the immune system via HLA-presented peptide ligands, exact knowledge of the peptidome constitution is fundamental for understanding this relationship. Here, we comprehensively describe the naturally presented HLA ligandome of colorectal carcinoma and corresponding nonmalignant colon (NMC) tissue. Mass spectrometry identified 35,367 and 28,132 HLA class I ligands on colorectal carcinoma and NMC, attributable to 7,684 and 6,312 distinct source proteins, respectively. Cancer-exclusive peptides were assessed on source protein level using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein analysis through evolutionary relationships (PANTHER), revealing pathognomonic colorectal carcinoma–associated pathways, including Wnt, TGFβ, PI3K, p53, and RTK-RAS. Relative quantitation of peptide presentation on paired colorectal carcinoma and NMC tissue further identified source proteins from cancer- and infection-associated pathways to be overrepresented merely within the colorectal carcinoma ligandome. From the pool of tumor-exclusive peptides, a selected HLA-ligand subset was assessed for immunogenicity, with the majority exhibiting an existing T-cell repertoire. Overall, these data show that the HLA ligandome reflects cancer-associated pathways implicated in colorectal carcinoma oncogenesis, suggesting that alterations in tumor cell metabolism could result in cancer-specific, albeit not mutation-derived, tumor antigens. Hence, a defined pool of unique tumor peptides, attributable to complex cellular alterations that are exclusive to malignant cells, might comprise promising candidates for immunotherapeutic applications. Significance: Cancer-associated pathways are reflected in the antigenic landscape of colorectal cancer, suggesting that tumor-specific antigens do not necessarily have to be mutation-derived but may also originate from other alterations in cancer cells. Cancer Res; 78(16); 4627–41. ©2018 AACR.

The aim of our study was to evaluate the immunohistochemical expression of SOX11, PAX5, TTF-1 and ISL-1 in medulloblastoma (MB) to investigate their diagnostic usefulness.Immunohistochemical expression of PAX5 (two antibodies: Dako, DAK-Pax5; and BD, clone 24), TTF-1 (Dako, 8G7G3/1), SOX11 (CL0142; Abcam) and ISL-1 (1 H9, Abcam) was analyzed using the h-score and Remmele score in 25 cases of MB.There were 18 MBs of classic and 7 of desmoplastic type. SOX11 was strongly expressed in all tumors. The expression of PAX5 was higher and more frequent in a case of DAK-Pax5 clone (25/25) than clone 24 (6/25). ISL-1 was positive in 11 (44%) and TTF-1 in 3 (12%) cases. ISL-1 expression correlated positively (p0.001), while TTF-1 correlated negatively with the age of patients (p=0.039). PAX5 expression correlated with ISL-1 (p=0.039) and showed a trend toward higher expression in the desmoplastic subtype (p=0.069).SOX11 is strongly and robustly expressed in MBs. PAX5 expression pattern differs substantially among two antibody clones. TTF-1 and ISL-1 is associated with the age of patients.

Primary lymphoma of the lung is a rare entity. Clinical features, optimal treatment, role of surgery and outcomes are not well defined, and the follow-up is variable in published data. Clinical data of 205 patients who were confirmed to have bronchus mucosa-associated lymphoid tissue lymphoma from December 1986 to December 2011 in 17 different centres worldwide were evaluated. Fifty-five per cent of the patients were female. The median age at diagnosis was 62 (range 28-88) years. Only 9% had a history of exposure to toxic substances, while about 45% of the patients had a history of smoking. Ten per cent of the patients had autoimmune disease at presentation, and 19% patients had a reported preexisting lung disease. Treatment modalities included surgery alone in 63 patients (30%), radiotherapy in 3 (2%), antibiotics in 1 (1%) and systemic treatment in 128 (62%). Patients receiving a local approach, mainly surgical resection, experienced significantly improved progression-free survival (p = 0.003) versus those receiving a systemic treatment. There were no other significant differences among treatment modalities. The survival data confirm the indolent nature of the disease. Local therapy (surgery or radiotherapy) results in long-term disease-free survival for patients with localized disease. Systemic treatment, including alkylating-containing regimens, can be reserved to patients in relapse after incomplete surgical excision or for patients with advanced disease. Copyright © 2015 John Wiley & Sons, Ltd.

Basal-cell carcinomas may show irregular, asymmetric subclinical growth. This study analyzed the efficacy of ‘breadloaf’ microscopy (serial sectioning) and three-dimensional (3D) microscopy in detecting positive tumor margins. Two hundred eighty-three (283) tumors (51.2%) were put into the breadloaf microscopy group; 270 tumors (48.8%) into the 3D microscopy group. The position of any detected tumor outgrowths was identified in clock face fashion. The time required for cutting and embedding the specimens and the examination of the microscopic slides was measured. Patient/tumor characteristics and surgical margins did not differ significantly. Tumor outgrowths at the excision margin were found in 62 of 283 cases (21.9%) in the breadloaf microscopy group and in 115 of 270 cases (42.6%) in the 3D microscopy group, constituting a highly significant difference (p

Background: Toll-like receptor (TLR) expression in patients with inflammatory bowel disease is increased when compared with healthy controls. However, the impact of TLR signaling during inflammatory bowel disease is not fully understood. Methods: In this study, we used a murine model of acute phase inflammation in bone marrow chimeric mice to investigate in which cell type TLR2/4 signal induction is important in preventing intestinal inflammation and how intestinal dendritic cells are influenced. Mice were either fed with wild-type bacteria, able to initiate the TLR2/4 signaling cascade, or with mutant strains with impaired signal induction capacity. Results: The induction of the TLR2/4 signal cascade in epithelial cells resulted in inflammation in bone marrow chimeric mice, whereas induction in hematopoietic cells had an opposed function. Furthermore, feeding of wild-type bacteria prevented disease; however, differing signal induction of bacteria had no effect on lamina propria dendritic cell activation. In contrast, functional TLR2/4 signals resulted in increased frequencies of CD103-expressing lamina propria and mesenteric lymph node dendritic cells, which were able to ameliorate disease. Conclusions: The TLR-mediated amelioration of disease, the increase in CD103-expressing cells, and the beneficial function of TLR signal induction in hematopoietic cells indicate that the increased expression of TLRs in patients with inflammatory bowel disease might result in counterregulation of the host and serve in preventing disease.

ABSTRACT: Since the discovery of ALK-positive anaplastic large-cell lymphoma in 1994 many other types of tumors showing ALK expression were disclosed. They form a heterogeneous group, including lung, renal and soft tissue tumors. The biological function of ALK, its role in carcinogenesis and impact exerted on the clinical outcome have been studied by many research groups. New drugs specifically dedicated for ALK inhibition, for example, crizotinib, have been synthesized and have become a viable treatment option for ALK-positive lung adenocarcinoma, and potentially for other ALK-positive cancers. This review summarizes the current state of knowledge concerning ALK-positive neoplasms, focusing on the clinical aspects of the subject.

OBJECTIVE Nonalcoholic fatty liver (NAFL) is thought to contribute to insulin resistance and its metabolic complications. However, some individuals with NAFL remain insulin sensitive. Mechanisms involved in the susceptibility to develop insulin resistance in humans with NAFL are largely unknown. We investigated circulating markers and mechanisms of a metabolically benign and malignant NAFL by applying a metabolomic approach. RESEARCH DESIGN AND METHODS A total of 265 metabolites were analyzed before and after a 9-month lifestyle intervention in plasma from 20 insulin-sensitive and 20 insulin-resistant subjects with NAFL. The relevant plasma metabolites were then tested for relationships with insulin sensitivity in 17 subjects without NAFL and in plasma from 29 subjects with liver tissue samples. RESULTS The best separation of the insulin-sensitive from the insulin-resistant NAFL group was achieved by a metabolite pattern including the branched-chain amino acids leucine and isoleucine, ornithine, the acylcarnitines C3:0-, C16:0-, and C18:0-carnitine, and lysophosphatidylcholine (lyso-PC) C16:0 (area under the ROC curve, 0.77 [P = 0.00023] at baseline and 0.80 [P = 0.000019] at follow-up). Among the individual metabolites, predominantly higher levels of lyso-PC C16:0, both at baseline (P = 0.0039) and at follow-up (P = 0.001), were found in the insulin-sensitive compared with the insulin-resistant subjects. In the non-NAFL groups, no differences in lyso-PC C16:0 levels were found between the insulin-sensitive and insulin-resistant subjects, and these relationships were replicated in plasma from subjects with liver tissue samples. CONCLUSIONS From a plasma metabolomic pattern, particularly lyso-PCs are able to separate metabolically benign from malignant NAFL in humans and may highlight important pathways in the pathogenesis of fatty liver–induced insulin resistance.

The increasing use of immunohistochemical and molecular investigations of lymphatic tissues results in more frequent detection of early lymphoid proliferations. These show some but not all features of malignant lymphomas without fulfilling the diagnostic criteria for the diagnosis of lymphoid malignancy. In addition to well-known premalignant B-cell proliferations, such as monoclonal gammopathy of unknown significance (MGUS) and monoclonal B-cell lymphocytosis (MBL), so-called in situ lymphomas have recently been described with minimal infiltrates of clonal B-cells in morphologically reactive lymphoid tissues which show the phenotypic and genetic features of specific B-cell lymphoma subtypes and often show a characteristic topographical distribution. This article addresses a group of clonal lymphoproliferations with usually localized disease and excellent clinical prognosis, such as pediatric follicular lymphoma and nodal marginal zone lymphoma. Another group of early lesions not addressed in this review are virally induced lymphoproliferations which represent a grey zone between purely reactive lesions and malignant lymphomas and may pose significant diagnostic as well as clinical problems. In this review diagnostic criteria for early or in situ lesions and their distinction from partial infiltration by malignant lymphoma are described.

Background Perinatal audit and the three-delays model are increasingly being employed to analyse barriers to perinatal health, at both community and facility level. Using these approaches, our aim was to assess factors that could contribute to perinatal mortality and potentially avoidable deaths at Rwandan hospitals. Methods Perinatal audits were carried out at two main urban hospitals, one at district level and the other at tertiary level, in Kigali, Rwanda, from July 2012 to May 2013. Stillbirths and early neonatal deaths occurring after 22 completed weeks of gestation or more, or weighing at least 500 g, were included in the study. Factors contributing to mortality and potentially avoidable deaths, considering the local resources and feasibility, were identified using a three-delays model. Results Out of 8424 births, there were 269 perinatal deaths (106 macerated stillbirths, 63 fresh stillbirths, 100 early neonatal deaths) corresponding to a stillbirth rate of 20/1000 births and a perinatal mortality rate of 32/1000 births. In total, 250 perinatal deaths were available for audit. Factors contributing to mortality were ascertained for 79% of deaths. Delay in care-seeking was identified in 39% of deaths, delay in arriving at the health facility in 10%, and provision of suboptimal care at the health facility in 37%. Delay in seeking adequate care was commonly characterized by difficulties in recognising or reporting pregnancy-related danger signs. Lack of money was the major cause of delay in reaching a health facility. Delay in referrals, diagnosis and management of emergency obstetric cases were the most prominent contributors affecting the provision of appropriate and timely care by healthcare providers. Half of the perinatal deaths were judged to be potentially avoidable and 70% of these were fresh stillbirths and early neonatal deaths. Conclusions Factors contributing to delays underlying perinatal mortality were identified in more than three-quarters of deaths. Half of the perinatal deaths were considered likely to be preventable and mainly related to modifiable maternal inadequate health-seeking behaviours and intrapartum suboptimal care. Strengthening the current roadmap strategy for accelerating the reduction of maternal and neonatal morbidity and mortality is needed for improved perinatal survival. Electronic supplementary material The online version of this article (doi:10.1186/s12884-017-1269-9) contains supplementary material, which is available to authorized users.

Background: The use of antimalarial drugs and the prevention of man and vector contact remain the major control and prevention strategy of malaria until the availability of effective and safe vaccine. In Africa, one of the major strategies to malaria control and prevention is the home based malaria strategy through which trained community drug distributors identify and provide antimalarial drugs to children under five years with fever. This research aims at exploring the capacity, performance, and motivation of CBAs in Tamale Metropolis, Northern region, Ghana Methodology: A Survey, in-depth interviews and short ethnographic techniques were conducted among 104 CBAs who were trained and given logistical support to assess and treat children less than five years with malaria presumptively at home. Participants were selected randomly and represented urban, peri-urban and rural settings. Results: 96.2% of respondents identified malaria by presence of fever while 92.3% used fever as a cardinal sign. More than 82% of participants provided early treatment in all the three location. 64.4% of participants administered the correct number of days while 32.7% administered daily doses correctly, only 24% of CBAs knew that the Antimalarial medications they use have some side effects. 77.9% knew when to repeat drug dose when child vomit or when parent forget to give the dose. Most of the participant had registers and were reporting monthly, however, only 26.2% are somewhat motivated by some of the existing of the motivational packages. Conclusion: The overall performance and skills demonstrated by the CBAs are encouraging in all the three settings but documentation and reporting remains a challenge. Community based initiatives should be strengthened and promoted to provide homemade solutions in saving lives especially in resources limited settings. If community interventions such as community drug distribution of antimalarial drugs are needed to improving access to malaria prevention, much attention to what motivates individuals to strengthen their spirit of volunteerism is required.

Treatment options for adrenocortical carcinoma (ACC) are very limited. In other solid tumors, small vaccination trials targeting the anti-apoptotic molecule survivin suggested immunological and clinical benefit in selected patients. Therefore, we investigated whether survivin might be a suitable target for immunotherapy in ACC. Survivin mRNA and protein expression was assessed in adrenal tissue specimens [by real-time-PCR in 29 ACC, 24 adrenocortical adenomas (ACA) and 12 normal adrenal glands; by immunohistochemistry in 167 ACCs, 15 ACA, and 5 normal adrenal glands]. Expression was correlated with clinical outcome using Kaplan-Meier and Cox regression analyses. The anti-apoptotic role of survivin was investigated in the SW13 ACC cell line using survivin siRNA. The presence of spontaneous survivin specific T-cells in peripheral blood was assessed by FACS dextramere staining in 29 ACC patients in comparison to healthy controls. Survivin mRNA in ACC was significantly overexpressed when compared with ACA or normal adrenal glands. Immunohistochemistry confirmed survivin protein expression in 97% of the ACCs. In 83% of samples, staining was moderate or high and clinical outcome in this subgroup showed a trend towards poorer prognosis [hazard ratio for death 2.28 (95% CI 0.99-5.28); p=0.053]. Survivin knockdown in SW-13 cell significantly increased the rate of apoptosis. Finally, spontaneous survivin-reactive T cells were detectable in 3 of 29 ACC patients. In conclusion, our data suggest that survivin could play an important role in the anti-apoptotic mechanisms in ACC and provide first hints that targeting survivin might be an interesting new therapeutic approach in this rare disease.

The purpose of this article is to measure perfusion parameters, including transit constant (K(trans)), in untreated follicular and diffuse large B cell lymphoma using volume perfusion CT, to establish their discriminating role and to search for a possible histopathologic background.Between January 2010 and June 2011, 46 consecutive patients with untreated histologically confirmed follicular lymphoma (n = 16) or diffuse large B cell lymphoma (n = 30) were enrolled. A 40-second volume perfusion CT of the tumor bulk using 6.9-cm z-axis coverage and a total of 26 volume measurements was performed. Blood flow (BF), blood volume (BV), and K(trans) were determined. Tumor size was recorded as the product of long- and short-axis diameters. In 13 of 46 patients, pathologic specimens of an appropriate size were available for assessment of microvessel density (MVD) and microvascular luminal diameter for comparison with volume perfusion CT measurements.Mean BF, BV, and K(trans) values were significantly higher in follicular lymphoma than in diffuse large B cell lymphoma, even after controlling for patient age and tumor size (p0.05, respectively). Although MVD was slightly, but not significantly, higher in follicular lymphoma versus diffuse large B cell lymphoma (p0.05), microvascular luminal diameter was significantly larger in follicular lymphoma than in diffuse large B cell lymphoma (p0.05). We defined cutoff values for BF, BV, and K(trans). If the cutoff points are met for all three parameters, the overall accuracy for correctly identifying diffuse large B cell lymphoma and follicular lymphoma was 90.5% and 87.5%, respectively.Volume perfusion CT allows assessment of differences in vascularity of follicular and diffuse large B cell lymphomas, reflecting vascular luminal variability and histopathologic anatomy.

Mantle cell lymphoma (MCL) can show diffuse, nodular and mantle zone growth patterns. We report on two cases of MCL with an unusual intrafollicular growth pattern and discuss the differential diagnosis. The first case was a small lymph node biopsy from a patient with a history of MCL in remission for 6 years. The lymph node showed a preserved architecture but with cyclin D1-positive cells exclusively confined to follicle centers, thus representing an unusual in situ pattern of recurrent disease. The second case was a lymph node biopsy infiltrated with classical diffuse MCL but with areas of intrafollicular growth pattern. Both cases exhibited the classical immunophenotype of MCL with CD20 positivity and co-expression of CD5, cyclin D1, BCL2, and SOX11. Proliferation rate, as assessed by Mib-1 immunostaining was

HISTORY AND ADMISSION FINDINGS A 65-year-old woman presented with reduced general condition and dyspnoea that was progressive over the last months. Clinical findings revealed an exophthalmus on the right, xanthelasm and mild peripheral oedema. Previously, a pericardiocentesis had been performed due to a large pericardial effusion. A previous CT scan showed a mass attached to the pericardium extending through the atrio-ventricular groove and a thickened aorta. In addition, a retroperitoneal fibrosis and an occlusion of both Aa. iliacae internae were found. INVESTIGATIONS The ECG showed sinus rhythm. Laboratory findings demonstrated a microcytic anemia and a renal failure. Chest radiography showed a large cardiac silhouette, while the transthoracic echocardiography revealed a recurrent large pericardial effusion. A PET/CT scan of the chest and abdomen showed a tissue infiltration of the retroperitoneal structures, a mass surrounding the right coronary artery and the right orbita. Finally, a femur biopsy confirmed the diagnosis of Erdheim-Chester disease. DIAGNOSIS, TREATMENT AND COURSE With the diagnosis Erdheim-Chester disease we started a high dose immunsuppressive therapy using glucocorticoids and interferon-a. Tumour size slightly decreased during the following 2 months, however the patient developed a severe urosepsis and died from multiorgan failure. CONCLUSIONS We report a case of an Erdheim-Chester disease with cardiovascular involvement primarily diagnosed due to a recurrent large pericardial effusion. In case of cardial tumors with interatrial septum or coronary artery involvement together with cerebral manifestations, an Erdheim-Chester disease should be taken into account.

Henopp T, Quintanilla-Martinez L, Fend F & Adam P (2011) Histopathology59, 139–142 Prevalence of follicular lymphoma in situ in consecutively analysed reactive lymph nodes Aims: Follicular lymphoma (FL) in situ is defined as strongly bcl-2-positive B cells in germinal centres of morphologically inconspicuous lymph nodes. The prevalence and biological and clinical significance of this lesion are still not clear. Therefore we aimed at the detection of the prevalence of this phenomenon in an unselected series of lymph nodes, as a surrogate for the normal population. Methods and results: All 1294 reactive lymph nodes from unselected consecutive surgical specimens of 132 patients in a 3-month period were stained for bcl-2 protein. The t(14;18) translocation was investigated by fluorescence in-situ hybridization (FISH) analysis. FL in situ was identified in 22 lymph nodes in 3/132 patients (2.3%) without evidence or history of malignant lymphoma, and confirmed by detection of the t(14;18) translocation by FISH. Interestingly, in one patient, a lymph node excised 2 years before also contained FL in situ. Conclusions: We found a prevalence of 2.3% for FL in situ lesions in an unselected series of lymph nodes, as a surrogate for the normal population. Taking into account the incidence of manifest FL, the risk of progression of this lesion is probably limited. It can be speculated that some FL in situ lesions do indeed represent an early step in lymphomagenesis, whereas others persist without further progression to overt FL. The underlying mechanisms, however, remain to be elucidated.

The aims of this study were to analyze the incidence and morphology of cyclin D1+ DLBCL and cases of Richter transformation (RT), and to elucidate possible molecular mechanisms of cyclin D1 overexpression. Seventy-two cases of de novo DLBCL and 12 cases of RT were included in this study. Cyclin D1 positivity was found in 10/66 (15%) cases of unselected de novo DLBCL and in 2/11 (18%) cases of RT. Seven independently identified cases of cyclin D1+ DLBCL, including one RT, were added to the study. Centroblastic morphology was found in 17/19 (89%) cases of cyclin D1+, most with a post-germinal center phenotype (CD10-, BCL6+, MUM1+). No alterations in the CCND1 gene indicative for a translocation t(11;14) were identified by FISH. Analysis of the MYC locus yielded gene copy alterations in five cases and no disruption of the gene locus in any case, suggesting an alternative mechanism of cyclin D1 deregulation.

Adrenocortical carcinoma is a rare but highly malignant neoplasm with still limited treatment options. Epidermal growth factor receptor (EGFR) has been shown to be overexpressed in many solid tumors, but its expression in adrenocortical carcinoma has been studied only in a limited number of cases. Therefore, we analyzed the expression of EGFR in 169 adrenocortical carcinoma samples and compared it with 31 adrenocortical adenomas. Additionally, in 30 cases of adrenocortical carcinoma, exons 18-21 of the EGFR gene were cloned and sequenced. EGFR expression was found in 128 of 169 adrenocortical carcinoma samples (76%), and in 60 of these samples (=36%) strong membrane staining was detected. However, there was no significant correlation with clinical outcome. In addition, all 30 sequenced cases revealed unmutated EGFR genes. In contrast, only 1 out of 31 adrenocortical adenomas weakly expressed the EGFR (3%). In summary, EGFR was overexpressed in more than three-quarters of adrenocortical carcinoma cases of this series. However, no mutations of the EGFR gene were found and EGFR expression was not of prognostic relevance. As EGFR is hardly expressed in adrenocortical adenomas, our results suggest that its expression in adrenocortical tumors indicates a malignant phenotype, which may be used in the differential diagnosis between adrenocortical adenomas and carcinomas.

The prototype of a salivary lymphoepithelial lesion is the autoimmune disease Sjogren's syndrome with the characteristic lymphoepithelial duct lesions (LEL). The distinction of Sjogren's syndrome from cases with initial transformation into associated marginal zone B-cell lymphoma (MALT type) can be very challenging, whereby the presence of small "halos" can lead to over-diagnosis. The HIV-associated cystic lymphoepithelial lesion can be histologically almost identical to Sjogren's syndrome and often needs clinical correlation. The sporadic lymphoepithelial cyst of the parotid gland is a frequent finding and has no clinical consequence; however, this entity needs to be identified and distinguished from the above-mentioned entities. The most frequent diagnosis in resected submandibular glands is chronic-fibrosing sialadenitis, so-called Kuttner's tumour. Altogether, there is a wide spectrum of lymphoepithelial interaction in the area of salivary glands, including biphasic lymphoepithelial tumours with an obligate lymphoid component, epithelial tumours with facultative tumour-associated lymphoid proliferation, and different processes of intraparotid lymph nodes. The immunohistological reaction for pan-keratin can be very helpful for a thorough pattern analysis of the different lymphoepithelial lesions. The relative frequency of the lesions in different salivary glands can also be diagnostically helpful.

Therapeutic progress in adrenocortical carcinoma (ACC) is severely hampered by its low incidence. Platinum-based chemotherapies are the most effective cytotoxic treatment regimens in ACC but response rates remain n=45), objective response to platinum compounds was observed in 3/21 patients (14.3%) with high ERCC1 expression and in 7/24 patients (29.2%) with low ERCC1 expression (P=0.23). ERCC1 expression was strongly correlated with overall survival after platinum treatment (median: eight months in patients with high ERCC1 versus 24 months in low ERCC1 expression, hazard ratio (HR) 2.95 (95% confidence interval (CI) 1.4–6.2), P=0.004). Multivariate analysis confirmed that high ERCC1 expression was a predictive factor for poor prognosis in platinum treated patients (HR 2.2, 95% CI 1.0–4.5, P=0.038). Our findings suggest that ERCC1 expression is the first factor for predicting survival in ACC patients treated with platinum-based chemotherapy.

Gene array studies indicated that osteopontin (OPN) mRNA is highly expressed in adrenocortical carcinomas (ACCs). OPN enhances invasiveness, proliferation, and metastasis formation, and is associated with poor survival in some malignant diseases. Integrin alphavbeta3 has been shown to mediate OPN effects on invasion. In this study, we demonstrated OPN and integrin alphavbeta3 expression in normal adrenal glands and benign adenomas, with staining seen exclusively in adrenocortical cells as well as even stronger staining in ACC. Western blot analysis confirmed overexpression of OPN in ACC (p0.01). With Matrigel invasion assays, we have shown that OPN greatly stimulates the invasiveness of NCI-h295 cells (six-fold increase, p0.001). Transfection with integrin alphavbeta3 further increased invasiveness after OPN stimulation (p0.001). This increase was reversed by the addition of an anti-integrin beta3 antibody, indicating a functional relationship of OPN and integrin alphavbeta3 in ACC. With tissue arrays, we confirmed high OPN expression in 147 ACC samples. However, no association with survival was seen in Kaplan-Meier analysis including 111 patients with primary tumours graded for OPN staining and follow-up data available. In conclusion, our in vitro data indicate that OPN and integrin alphavbeta3 may act as a functional complex facilitating the invasiveness of adrenocortical tumours. This relationship remains of relevance to our understanding of carcinogenesis, but further studies are needed to address the physiological and pathological function of OPN in adrenal tissue.

Mantle cell lymphoma (MCL) is an aggressive lymphoid tumour characterized by the translocation t(11;14)(q13;q32) and a poor clinical outcome (median survival: 3-4 years). Recent studies revealed that increased proliferation of the tumour cells and certain chromosomal aberrations, such as deletions of 17p13 and 9p21 represent major adverse biological markers in this disease, although the molecular targets of chromosomal imbalances in MCL have not been identified for the large majority of loci affected. To correlate histomorphological and proliferation features of MCL with genetic findings, we investigated 223 MCL by fluorescence in situ hybridization (FISH) (n = 157) and/or classical cytogenetic banding analysis (n = 129). FISH analysis turned out to be distinctly more sensitive in the delineation of aberrations. Complex karyotypic alterations were associated with higher proliferation indices and inferior prognosis. A comprehensive analysis of biological features including genetic alterations in MCL by hierarchical clustering resulted in the delineation of four tumour subgroups differing with respect to their genetic constitution and suggesting different transformation or progression pathways. Moreover, in one of the groups identified, a more indolent clinical behaviour was associated with few secondary aberrations and fewer known high-risk chromosomal aberrations, which points to the importance of the quality of karyotypic evolution in MCL tumours.

Successful treatment of multicentric Castleman's disease with combined immunochemotherapy in an AIDS patient with multiorgan failure

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.

Genetic rearrangement of FOXP1 is predominantly detected in a subset of diffuse large B-cell lymphomas with extranodal presentation

Follicular lymphoma (FL) typically presents as a systemic disease (stages III/IV). We repeatedly observed in cases with conserved reactive follicle structures (so-called partial infiltration) an association with a limited clinical stage (I/II). In this study, we analyzed 53 lymph node biopsies of FL with conserved reactive follicle structures. In 44 cases (83%) of the patients with partial infiltration, a limited stage of disease (Ann Arbor stage I/II) was found, whereas only 9 of 53 cases (17%) suffered from a systemic disease. In those cases with at least one follicle totally spared by lymphoma, 95% of the patients (38 of 40 cases) presented with a limited stage (I/II) of disease, compared with only 20% (10 of 49 cases) in a control group with full-blown infiltration (P < 0.001). Analyzing systematically all 321 FL cases sent to the Reference Center Wurzburg in the year 2001, reactive follicle remnants were detected in 34 of 321 (10.6%) cases with 26 of 34 (76%) tumors showing limited stage (I/II) disease, including all 18 cases with at least one totally spared follicle. Our results therefore show a clear association between the occurrence of preserved reactive follicles in FL and limited disease stage.

To the editor: Follicular lymphoma in situ (FLIS) is characterized by the presence of a B-cell population with immunophenotypic and genotypic features of follicular lymphoma (FL) but exclusively localized to germinal centers (GCs) in morphologically reactive lymph nodes.[1][1] FLIS lesions are

FISH studies on 37 ocular MALT-type lymphomas yielded chromosomal translocations affecting MAL andT1 BCL10 in 1 case each, no evidence for a break in the FOXP1 locus, and trisomy 3 in 14 out of 34 cases (41%). Three out of 8 cases analyzed used the highly mutated VH3-23 gene and showed ongoing somatic hypermutations.

Beim Cushing-Syndrom produziert der Korper zu viel Kortisol oder erhalt zu viele synthetische Glukokortikoide. Die Diagnose des Hyperkortisolimus ist anhand der Anamnese und klinischen Symptome meist rasch gestellt. Aufgrund der Bandbreite an moglichen Ursachen ist die Differenzialdiagnostik jedoch alles andere als trivial. Lesen Sie hier in Kurzform zwei Falle von Patientinnen mit Cushing-Syndrom und erfahren Sie mehr uber die vielfaltigen Ursachen. Den ausfuhrlichen „Tubinger Fall“ mit allen Details zu den Patientinnen und Untersuchungen, vielen Abbildungen und den Hintergrunden finden Sie im Internet.

Due to its profound therapeutic consequences, the distinction between thymoma and T-lymphoblastic lymphoma in needle biopsies is one of the most challenging in mediastinal pathology. One essential diagnostic criterion favouring thymoma is the demonstration of increased numbers of keratin-positive epithelial cells by immunohistochemistry. Loss of keratin expression in neoplastic epithelial cells could lead to detrimental misdiagnoses. We here describe a series of 14 thymic epithelial tumours (11 type B2 and B3 thymomas, 3 thymic carcinomas) with loss of expression of one or more keratins. Cases were analysed for expression of various keratins and desmosomal proteins by immunohistochemistry and immunofluorescence and compared with 45 unselected type B thymomas and 24 thymic carcinomas arranged in a multitissue histological array. All 14 cases showed highly reduced expression of at least one keratin, three cases were completely negative for all keratins studied. Of the 14 cases, 13 showed strong nuclear expression of p63. Expression of desmosomal proteins was preserved, suggesting intact cell contact structures. Loss of expression of broad-spectrum-keratins and K19 was observed in 3 and 5 % of unselected thymomas and in 30 and 60 % of thymic carcinomas. A proportion of keratin-depleted thymomas contained giant cells, reminiscent of thymic nurse cells. Loss of keratin expression in type B2 and B3 thymomas is an important diagnostic pitfall in the differential diagnosis with T-lymphoblastic lymphoma and can be expected in 5 % of cases. A panel of epithelial markers including p63 is warranted to ensure correct diagnosis of keratin-negative mediastinal tumours.

The genetic hallmark of Burkitt lymphoma (BL) is the t(8;14)(q24;q32) and its variants leading to activation of the MYC oncogene. It is a matter of debate whether true BL without MYC translocation exists. Here, we identified 59 lymphomas concordantly called BL by 2 gene expression classifiers among 753 B-cell lymphomas. Only 2 (3%) of these 59 molecular BL lacked a MYC translocation, which both shared a peculiar pattern of chromosome 11q aberration characterized by interstitial gains including 11q23.2-q23.3 and telomeric losses of 11q24.1-qter. We extended our analysis to 17 MYC-negative high-grade B-cell lymphomas with a similar 11q aberration and showed this aberration to be recurrently associated with morphologic and clinical features of BL. The minimal region of gain was defined by high-level amplifications in 11q23.3 and associated with overexpression of genes including PAFAH1B2 on a transcriptional and protein level. The recurrent region of loss contained a focal homozygous deletion in 11q24.2-q24.3 including the ETS1 gene, which was shown to be mutated in 4 of 16 investigated cases. These findings indicate the existence of a molecularly distinct subset of B-cell lymphomas reminiscent of BL, which is characterized by deregulation of genes in 11q.

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) comprises 7-8% of B-cell lymphomas and commonly originates from a background of long-standing chronic inflammation. An association with distinct bacteria species has been confirmed for several anatomical sites of MALT lymphoma. For pulmonary MALT lymphoma, however, a clear link with an infectious agent or autoimmune disorder has not yet been reported. Using a 16S rRNA gene-based approach, we have recently identified Achromobacter (Alcaligenes) xylosoxidans in eight of nine cases of pulmonary MALT lymphoma. A. xylosoxidans is a gram-negative betaproteobacterium with low virulence, but high resistance to antibiotic treatment. To further examine a potential association with A. xylosoxidans, 124 cases of pulmonary MALT lymphoma and 82 control tissues from six European countries were analysed using a specific nested PCR. Although prevalence rates for A. xylosoxidans varied significantly from country to country, they were consistently higher for MALT lymphoma as compared to controls. Overall, 57/124 (46%) pulmonary MALT lymphomas and 15/82 (18%) control tissues were positive for A. xylosoxidans (P = 0·004). Whether the significant association of A. xylosoxidans with pulmonary MALT lymphoma demonstrated in our study points to a potential causal role in the pathogenesis of this lymphoma will require further studies.

Follicular lymphoma (FL) is characterized besides the t(14;18)(q32;q21), by recurrent chromosomal alterations and somatic mutations. In this study, we analyzed cases of FL in situ (FLIS) without manifest FL (mFL), partial involvement by FL (PFL) and paired cases of FLIS and mFL to detect possible early chromosomal imbalances, mutations, as well as DNA-methylation patterns of genomic regions of selected genes. We demonstrate that all paired FLIS and mFL cases were clonally related, based on IGH rearrangement patterns and BCL2 breakpoint sequences. FLIS and PFL had no or few secondary chromosomal imbalances detectable by array comparative genomic hybridization (FLIS 0.8 copy number alterations (CNA)/case; PFL 2.0 CNA/case; mFL 6.3 CNA/case) and a lower level of DNA methylation of genes recurrently de novo methylated in lymphomas, as compared with mFL. EZH2 Tyr641 mutations were detected in a subset of both FLIS (2/9) and PFL (1/3) cases. In conclusion, these findings provide evidence that FLIS represents a FL precursor lesion of long-lived clonal B cells carrying the t(14;18) with no or few secondary genetic changes. Our data suggest that there may be more than one distinct lesion driving the progression from FLIS to manifest lymphoma.

C/EBPβ (CCAAT enhancer binding protein) is a transcription factor that plays a crucial role in survival and transformation of ALK+ anaplastic large cell lymphoma (ALCL). The aim of this study was to identify the downstream targets of C/EBPβ responsible for ALK-mediated oncogenesis. C/EBPβ was knocked down in ALK+ ALCL cell lines with a C/EBPβ-shRNA, followed by gene expression profiling (GEP). GEP analysis revealed a reproducible signature of genes that were significantly regulated by C/EBPβ. Classification into biological categories revealed overrepresentation of genes involved in the immune response, apoptosis and cell proliferation. Transcriptional regulation by C/EBPβ was found in 6 of 11 (BCL2A1, G0S2, TRIB1, S100A9, DDX21 and DDIT4) genes investigated by chromatin immunoprecipitation. We demonstrated that BCL2A1, G0S2 and DDX21 play a crucial role in survival and proliferation of ALK+ ALCL cells. DDX21, a gene involved in rRNA biogenesis, was found differentially overexpressed in primary ALK+ ALCL cases. All three candidate genes were validated in primary ALCL cases by either immunohistochemistry or RT-qPCR. In conclusion, we identified and validated several key C/EBPβ-regulated genes with major impact on survival and cell growth in ALK+ ALCL, supporting the central role of C/EBPβ in ALK-mediated oncogenesis.

3D histology is intended for tumors at difficult sites where a tissue-saving surgical technique is needed or if local R0 resection must be ensured due to the aggressive growth of the tumor (Table 8.1) [1]. Precondition for this technique is a continuous local, clinically invisible infiltration of the tumor. Therefore, the margins of the excised tumor have to be investigated histologically in order to verify total removal of the tumor. For safety reasons, it is recommendable to increase the width of the safety margins in the primary excision of the tumor relative to the overall size of the tumor. Only in more distinguished locations with important structures or for aesthetical reasons, it is recommendable to choose smaller safety margins in order to save healthy tissue. However, it is imperative that in any case, the full removal is diagnosed by the presence of histologically clear margins.

Follicular lymphoma (FL) is characterized by the translocation t(14;18)(q32;q21) resulting in constitutive overexpression of BCL2. However, in 10% to 15% of FL grade 1/2, immunohistochemical staining for BCL2 remains negative. To analyze the incidence of BCL2 negativity and the underlying molecular mechanisms in FL grade 1/2, BCL2 expression was investigated with 3 antibodies (clones 100D5, E17, SP66). The presence of a break in the BCL2 locus was determined by fluorescence in situ hybridization. The region of the BCL2 gene where the epitope of the standard BCL2 antibody resides was sequenced. Twenty-two (9.2%) of 240 identified cases of FL grade 1/2 were negative with the standard BCL2 antibody. Of these, 12 cases (55%) carried a break in the BCL2 gene locus, which, in all but one case, correlated with BCL2 expression using the alternative antibodies E17 and SP66 and with missense mutations of BCL2. Ten (45%) of the 22 cases had an intact BCL2 gene locus; 2 cases carried a BCL6/IGH translocation. All 10 cases were negative for the E17/SP66 antibodies and showed a wild-type sequence of BCL2. Six of these showed an aberrant phenotype, with CD10 negativity (30%) or CD23 expression (30%). In summary, the alternative E17/SP66 antibodies identify 2 immunohistochemically and genetically distinct subgroups of BCL2-"negative" FL grade 1/2.

Recently, the occurrence of cyclin D1-positive B cells with mantle cell lymphoma phenotype in the inner mantle zones of morphologically inconspicuous lymph nodes has been described and termed mantle cell lymphoma 'in situ'. Prevalence and clinical significance of this lesion and related minimal mantle cell lymphoma infiltrates in reactive lymphoid tissues of healthy individuals, and of mantle cell lymphoma patients are unknown. All 1292 reactive lymph nodes from unselected consecutive surgical specimens of 131 patients without a history of lymphoma obtained over a 3-month period were stained for cyclin D1. In addition, all morphologically reactive lymph nodes and benign-appearing extranodal lymphoid infiltrates of patients diagnosed with mantle cell lymphoma in the years 2000-2011 were studied. Samples predating the lymphoma diagnosis for at least 2 months were available from 37/423 (9%) patients. A mantle cell lymphoma 'in situ' was not identified in any of the two groups. However, in four patients with subsequent mantle cell lymphoma diagnosis, an early manifestation of mantle cell lymphoma was detected retrospectively, antedating the lymphoma diagnosis for 2-86 months. In six mantle cell lymphoma patients, only small groups of cyclin D1-positive cells in morphologically reactive extranodal infiltrates were detected >2 months before the diagnosis of mantle cell lymphoma (range 3-59 months). Mantle cell lymphoma 'in situ' is an extremely rare phenomenon in morphologically reactive lymph nodes, in line with the low prevalence of t(11;14)-positive cells described in the peripheral blood of a healthy population. In mantle cell lymphoma patients, however, immunohistochemically detectable infiltrates of mantle cell lymphoma cells antedating the lymphoma diagnosis were found in a significant proportion of cases (10/37=27%). These consisted either of early mantle cell lymphoma with mantle zone growth pattern, or small extranodal accumulations of cyclin D1+ cells, whereas typical mantle cell lymphoma 'in situ' was not detected.

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) of the elderly has been included in the 2008 WHO classification as a new provisional entity and is defined as blastic, clonal B-cell proliferation associated with EBV occurring in patients over 50 years of age, presumably due to senescence of the immune system. Secondary immunodeficiencies must be excluded. Morphologically, the predominant polymorphic subtype shows a mixed proliferation of large transformed cells, plasma cells, plasmablasts, lymphocytes, and commonly Reed-Sternberg (RS)-like cells, whereas the monomorphic subtype reveals sheets of large cells. An additional characteristic feature is large areas of "geographical" necrosis. EBV+ DLBCL of the elderly is positive for pan-B cell markers and often for CD30. EBV infection detected by Epstein Barr early RNA in situ hybridization should be present in the majority of tumor cells. Most cases express LMP1 and up to 32% EBNA2, the latter a sign of an impaired immune system. The most challenging differential diagnosis is EBV+ classical Hodgkin lymphoma in older patients. Strong, homogeneous expression of B-cell markers, including transcription factors OCT2 and BOB.1, and lack of CD15 support a diagnosis of EBV+ DLBCL. EBV+ DLBCL of the elderly accounts for 8% to 10% of DLBCL in Asian countries, but seems to be uncommon in Western populations, indicating an ethnic or geographic predisposition. Clinically, patients may present with nodal or extranodal involvement. B-symptoms and poor performance status are common, and prognosis is significantly inferior compared with EBV- cases. Whether EBV+DLBCL of the elderly represents a true entity or only a DLBCL variant remains to be determined.

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma of the elderly was included as a provisional entity in the 2008 WHO lymphoma classification. Most reports of this disease come from Asia and little is known about it in other regions of the world, including Latin America. Therefore, in this study, 305 diffuse large B-cell lymphomas in patients above 50 years were analyzed, 136 from Mexico and 169 from Germany. EBV was detected by Epstein-Barr early RNA (EBER) in situ hybridization. Only cases with EBER+ in the majority of tumor cells were regarded as EBV+ diffuse large B-cell lymphoma. The prevalence of EBV+ diffuse large B-cell lymphoma in Mexican patients was found to be 7% (9 of 136), whereas only 2% (4 of 169) of the German cases were positive. The median age at diagnosis was 66 years in the Mexican cohort, as opposed to 77 years in the German group. The site of presentation was in both groups predominantly nodal in nine cases (70%) and extranodal in four cases (30%). Of the 13 EBV+ cases, 10 (77%) were classified as polymorphic and 3 (23%) as monomorphic type. The polymorphic cases showed a non-germinal center B-cell immunophenotype (CD10- MUM1+). Twelve cases (92%) were LMP1 positive and two (15%) expressed EBNA2. An interesting finding was the high frequency of EBV type B with the LMP1 30 bp deletion found in the Mexican cases (50%). Eight of the 11 evaluable cases were B-cell monoclonal by polymerase chain reaction. In summary, we found a similar prevalence of EBV+ diffuse large B-cell lymphoma of the elderly in a Mexican population compared with what has been reported in Asian countries, and in contrast to the low frequency in Western populations (1-3%). However, compared with the Asian series, the Mexican patients were younger at diagnosis, presented predominantly with nodal disease and rarely expressed EBNA2 protein.

Paratesticular fibrous pseudotumor (nodular periorchitis, inflammatory pseudotumor of the spermatic cord) is a rare, benign condition of unknown etiology characterized by solitary or multiple intrascrotal nodules composed of dense fibrous tissue with a variable, sometimes sparse inflammatory infiltrate. Based on certain similarities to other fibroinflammatory disorders characterized by infiltrates of IgG4-expressing plasma cells and recently subsumed under the heading of IgG4-mediated diseases, we investigated the plasma cell distribution and immunoglobulin isotypes in three cases of paratesticular fibrous and inflammatory pseudotumor. All three cases showed a high number of IgG4-positive plasma cells with an IgG4 to IgG ratio of 44–48%. This finding indicates that paratesticular fibrous pseudotumor might belong to the growing list of IgG4-related diseases, which by now includes such diverse entities as retroperitoneal fibrosis, sclerosing pancreatitis and cholangitis, Riedel’s thyroiditis, or sclerosing sialadenitis.

Owing to the rarity of adrenocortical carcinoma (ACC) no prognostic markers have been established beyond stage and resection status. Accelerated glycolysis is a characteristic feature of cancer cells and in a variety of tumour entities key factors in glucose metabolism like glucose transporter 1 and 3 (GLUT1 and -3), transketolase like-1 enzyme (TKTL1) and pyruvate kinase type M2 (M2-PK) are overexpressed and of prognostic value. Therefore, we investigated the role of these factors in ACC. Immunohistochemical analysis was performed on tissue microarrays of paraffin-embedded tissue samples from 167 ACCs, 15 adrenal adenomas and 4 normal adrenal glands. Expression was correlated with baseline parameters and clinical outcome. GLUT1 and -3 were expressed in 33 and 17% of ACC samples respectively, but in none of the benign tumours or normal adrenals glands. By contrast, TKTL1 and M2-PK were detectable in all benign tissues and the vast majority of ACCs. GLUT1 expression was strongly associated with prognosis in univariate and multivariate analysis (P

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-kappa B 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. Copyright (C) 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Adrenocortical carcinoma (ACC) is a rare malignancy with poor prognosis. In advanced disease, mitotane given as monotherapy or combined either with etoposide, doxorubicin, and cisplatin or with streptozotocin is the recommended first-line therapy. However, many patients have progressive disease despite treatment with these regimens.Our objective was to evaluate the efficacy of the epidermal growth factor receptor inhibitor erlotinib plus gemcitabine as salvage therapy in ACC patients with very advanced ACC.The study consisted of case series collected from different centers (primary care and referral centers) in Germany in 2006-2007.Patients registered with the German ACC Registry with progressive ACC after two to four previous systemic therapies were offered treatment with erlotinib and gemcitabine. Oral erlotinib (100 mg/d) was administered on a daily basis and gemcitabine (800 mg/m(2)) iv every 14 d.We evaluated tumor response according to response evaluation criteria in solid tumors (RECIST) criteria after 12 wk of treatment.Ten patients have been treated with erlotinib and gemcitabine. Only one in 10 patients experienced a minor response (progression-free survival 8 months), whereas eight patients had progressive disease at the first staging. One patient had to stop therapy after the first administration of gemcitabine due to cerebral seizure. Nine of 10 patients had died after a median of 5.5 months after treatment initiation. In addition to the seizure, one patient experienced severe pneumonia (grade III), and in one, gemcitabine administration had been delayed due to prolonged neutropenia. All other adverse events were mild (grade I-II).Salvage chemotherapy using erlotinib plus gemcitabine has very limited to no activity in patients with very advanced ACC.

Mantle cell lymphomas (MCL), characterized by the t(11;14)(q13;q32), frequently carry secondary genetic alterations such as deletions in chromosome 17p involving the TP53 locus. Given that the association between TP53-deletions and concurrent mutations of the remaining allele is weak and based on our recent report that the Hypermethylated in Cancer 1 (HIC1) gene, that is located telomeric to the TP53 gene, may be targeted by deletions in 17p in diffuse large B-cell lymphoma (DLBCL), we investigated whether HIC1 inactivations might also occur in MCL. Monoallelic deletions of the TP53 locus were detected in 18 out of 59 MCL (31%), while overexpression of p53 protein occurred in only 8 out of 18 of these MCL (44%). In TP53-deleted MCL, the HIC1 gene locus was co-deleted in 11 out of 18 cases (61%). However, neither TP53 nor HIC1 deletions did affect survival of MCL patients. In most analyzed cases, no hypermethylation of the HIC1 exon 1A promoter was observed (17 out of 20, 85%). However, in MCL cell lines without HIC1-hypermethylation, the mRNA expression levels of HIC1 were nevertheless significantly reduced, when compared to reactive lymph node specimens, pointing to the occurrence of mechanisms other than epigenetic or genetic events for the inactivation of HIC1 in this entity.

Chlamydia pneumoniae, Chlamydia trachomatis and Chlamydia psittaci were detected at low frequencies (

Follicular lymphoma (FL) constitutes the neoplastic equivalent of germinal center B-cells. Like its physiological counterpart, FL grows in (atypical) follicular structures, the formation of which is as yet poorly understood. Recent data indicate that in early tumour stages, neoplastic FL cells home to and colonise reactive germinal centers. Laser microdissection (LMD) and micromanipulation techniques now allow for the molecular genetic analysis of single cell mutation patterns in FL. The purpose of the present study was the analysis of the sequence and order of somatic mutations in FL, i.e. the influence of the germinal center microenvironment on the clonal evolution in different grades of FL. By generating phylogenetic trees as calculated from tumour cell sequences, the clonal evolution from a putative progenitor cell was elucidated and finally, the tumour cell migration pattern in disease progression was assessed by analyzing biopsies at different time points in relapsed tumours. Four patients suffering from FL were included in the study. A primary FL grade 1 showed clustering of genetically related subclones in distinct follicles. A moderate interfollicular exchange of tumour cells was detected. Three cases of FL grade 2 were found to show decreased subclonal clustering in follicles and an increase in the interfollicular migration. Accumulations of replacement mutations in antigen binding domains (CDR) and silent mutations in non-antigen binding domains (FR), respectively, indicating antigen influence on hypermutation were only found in the case of FL grade 1. Our conclusion is that the microenvironment in germinal centers exercises influence on clonal evolution and tumour cell distribution patterns in FL. With increasing histologic grade during disease progression, a reduced intraclonal diversity and selection of subclones also occurs outside the setting of transformation to high-grade lymphoma. Antigen-dependent hypermutations were only seen in FL grade 1, while in progressed FL, random mutation patterns and a decrease of clonal diversity were found.

Mantle cell lymphoma (MCL) is a distinctive type of non-Hodgkin lymphoma (NHL) that is considered an aggressive neoplasm. The clinical course, however, is variable, with some patients living less than a year while others survive for more than 10 years.[1][1] Therefore, many attempts have been made