Pathogenic Variants Associated with Epigenetic Control and the NOTCH Pathway Are Frequent in Classic Hodgkin Lymphoma.

Classic Hodgkin lymphoma (cHL) constitutes a B-cell neoplasm derived from germinal center lymphocytes. Despite high cure rates (80-90%) obtained with the current multiagent protocols, a significant proportion of cHL patients experience recurrences, characterized by a lower sensitivity to second-line treatments. The genomic background of chemorefractory cHL is still poorly understood, limiting personalized treatment strategies based on molecular features. In this study, using a targeted next-generation sequencing (NGS) panel specifically designed for cHL research, we compared chemosensitive and chemorefractory diagnostic tissue samples of cHL patients. Furthermore, we longitudinally examined paired diagnosis-relapsesamples of chemorefractory cHL in order to define patterns of dynamic evolution and clonal selection. Pathogenic variants in NOTCH1 and NOTCH2 genes frequently arise in cHL. Mutations in genes associated with epigenetic regulation (CREBBP and EP300) are particularly frequent in relapsed/refractory cHL. The appearance of novel clones characterized by mutations previously not identified at diagnosis is a common feature in cHL cases showing chemoresistance to frontline treatments. Our results expand current molecular and pathogenic knowledge of cHL and support the performance of molecular studies in cHL prior to the initiation of first-line therapies.

Whole slide imaging of tumour microenvironment in classical Hodgkin's lymphoma: development of a clinical prediction model based on programmed death-ligand 1 and tumorous Reed-Sternberg cells.

AIMS: The prognostic impact of programmed death-ligand 1 (PD-L1) cells in classic Hodgkin lymphoma (cHL) tumour microenvironment remains undefined. METHODS: Model development via Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis guidelines were followed. PD-L1+ and CD30+ tumoral Reed-Sternberg cells were quantified through whole slide imaging and digital image analysis in 155 digital histopathological slides of cHL. Univariate and multivariate survival analyses were performed. The analyses were reproduced for patients with advanced stages (IIB, III and IV) using the Advanced-stage cHL International Prognostic Index. RESULTS: The PD-L1/CD30 ratio was statistically significantly associated with survival outcomes. Patients with a PD-L1/CD30 ratio above 47.1 presented a shorter overall survival (mean OS: 53.7 months; 95% CI: 28.7 to 78.7) in comparison with patients below this threshold (mean OS: 105.4 months; 95% CI: 89.6 to 121.3) (p=0.04). When adjusted for covariates, the PD-L1/CD30 ratio retained prognostic impact, both for the OS (HR: 1.005; 95% CI: 1.002 to 1.008; p=0.000) and the progression-free survival (HR: 3.442; 95% CI: 1.045 to 11.340; p=0.04) in a clinical and histopathological multivariate model including the male sex (HR: 3.551; 95% CI: 0.986 to 12.786; p=0.05), a percentage of tumoral cells ≥10.1% (HR: 1.044; 95% CI: 1.003 to 1.087; p=0.03) and high risk International Prognostic Score (≥3 points) (HR: 6.453; 95% CI: 1.970 to 21.134; p=0.002). CONCLUSIONS: The PD-L1/CD30 ratio identifies a group of cHL patients with an increased risk of treatment failure. Its clinical application can be performed as it constitutes an easy to implement pathological information in the diagnostic work-up of patients with cHL.

Identification of prognostic factors in classic Hodgkin lymphoma by integrating whole slide imaging and next generation sequencing.

Digital pathology and genomics are increasingly used to improve our understanding of lymphoid neoplasms. Algorithms for quantifying cell populations in the lymph node and genetics can be integrated to identify new biomarkers with prognostic impact in classic Hodgkin lymphoma (cHL). In 16 cHL patients, we have performed whole slide imaging (WSI) analysis and quantification of CD30+, CD20+, CD3+ and MUM1+ cells in whole tissue slides, and Next Generation Sequencing (NGS) in formalin fixed paraffin-embedded (FFPE) tissue, using a widely used NSG panel (Oncomine® Focus Assay) to define genetic variants underlying tumor development. The different cell populations could be successfully identified in scanned slides of cHL, supporting the inclusion of WSI in the histopathological evaluation of cHL as an adequate method for the quantification of different cell populations. We also performed genetic profiling in FFPE samples of cHL leading to the identification of copy number variations in the Neurofibromin 1 gene (17q11.2) and the Androgen Receptor gene (Xq12) accompanied by chromosomal gains and losses in CDK4, KRAS and FGFR2 genes. Progression-free survival (PFS) was statistically significantly higher in cHL patients with amplification in the NF1 gene combined with CD3+ cells above 28.6% (p = 0.006) and MUM1+ cells above 21.8% (p < 0.001). Moreover, patients with MUM1+ cells above 21.8% showed a statistically significantly higher PFS when combined with amplification of the AR gene (p < 0.001) and wild-type KRAS (p < 0.001). The integration of WSI analysis and DNA sequencing could be useful to improve our understanding of the biology of cHL and define risk subgroups.

Whole-slide image analysis identifies a high content of Hodgkin Reed-Sternberg cells and a low content of T lymphocytes in tumor microenvironment as predictors of adverse outcome in patients with classic Hodgkin lymphoma treated with ABVD.

Classic Hodgkin lymphoma (cHL) constitutes the most frequent lymphoma in young adults. Its histopathology is unique as a scattered tumor population, termed Hodgkin Reed-Sternberg (HRS) cells is diluted in a prominent tumor microenvironment (TME) composed of T lymphocytes, B lymphocytes, macrophages, neutrophils, eosinophils and histiocytes. Traditionally, the identification of prognostic biomarkers in the cHL TME has required visual inspection and manual counting by pathologists. The advent of whole-slide imaging (WSI) and digital image analysis methods could significantly contribute to improve this essential objective in cHL research, as a 10-20% of patients are still refractory or relapsed after conventional chemotherapy. In this work, we have digitized a total of 255 diagnostic cHL slides and quantified the proportion of HRS cells (CD30), B cells (CD20) and T cells (CD3) by digital image analysis. Data obtained where then correlated with the overall survival (OS) and progression free survival (PFS) of cHL patients. Quantification of HRS cells, B cells and T cells reflects the biological heterogeneity of the different cHL histological subtypes analyzed. A percentage of 2.00% of HRS cells statistically significantly discriminated between patients achieving a complete metabolic response (CMR) and refractory or relapsed (R/R) patients both for the OS (P=0.001) and PFS (P=0.005). Furthermore, patients with a percentage of T cells below the 26.70% in the TME showed a statistically significantly shorter OS (P=0.019) and PFS (P=0.041) in comparison with patients above this threshold. A subgroup of patients with a low content of T cells and high content of HRS cells exhibited a special aggressive clinical course. Currently, there is the need to implement quantitative and easy scalable methods to enhance clinical translation, as the cHL TME plays a central role in the clinical course of the disease. The results of this study could contribute to the identification of prognostic biomarkers specifically looking at the cHL TME and their inclusion in future clinical trials.

The Need for Standardization in Next-Generation Sequencing Studies for Classic Hodgkin Lymphoma: A Systematic Review.

Classic Hodgkin lymphoma (cHL) constitutes a B cell-derived neoplasm defined by a scarce tumoral population, termed Hodgkin and Reed-Sternberg (HRS) cells, submerged into a histologically heterogeneous microenvironment. The paucity of HRS cells has historically hampered genetic studies, rendering the identification of the recurrent genetic lesions and molecular pathways deregulated in this lymphoma difficult. The advent of high-throughput sequencing methods such as next-generation sequencing (NGS) could sensibly optimize the identification of the mutational landscape of cHL. However, there is no current consensus either in the design of panels for targeted NGS or in its most relevant clinical applications. In this work, we systematically review the current state of NGS studies of cHL, stressing the need for standardization both in the candidate genes to be analyzed and the bioinformatic pipelines. As different institutions have developed and implemented their own customized NGS-based protocols, to compare and systematically review the major findings of this ongoing research area could be of added value for centers that routinely perform diagnostic, monitoring and genotyping strategies in cHL samples. The results of this systematic review should contribute to the interdepartmental harmonization and achievement of a consensus in the current clinical applications of NGS studies of cHL.

Prognostic Role of the Expression of Latent-Membrane Protein 1 of Epstein-Barr Virus in Classical Hodgkin Lymphoma.

The prognostic impact of the presence of Epstein-Barr virus (EBV) in classical Hodgkin lymphoma (cHL) is controversial. Previous studies reported heterogeneous results, rendering difficult the clinical validation of EBV as a prognostic biomarker in this lymphoma. The objective of this study was to evaluate the survival impact of the expression of EBV Latent-Membrane Protein 1 (EBV-LMP1) in tumoral Hodgkin-Reed-Sternberg (HRS) cells of primary diagnostic samples of cHL. Formalin-Fixed Paraffin-Embedded (FFPE) lymph node samples from 88 patients with cHL were analyzed. Patients were treated with the standard first-line chemotherapy (CT) with Adriamycin, Bleomycin, Vinblastine and Dacarbazine (ABVD) followed by radiotherapy. The Kaplan-Meier method and the Cox proportional hazards model were used for carrying out the survival analysis. In order to investigate whether the influence of EBV was age-dependent, analyses were performed both for patients of all ages and for age-stratified subgroups. In bivariate analysis, the expression of EBV was associated with older age (p = 0.011), mixed cellularity subtype cHL (p < 0.001) and high risk International Prognostic Score (IPS) (p = 0.023). Overall survival (OS) and progression-free survival (PFS) were associated with the presence of bulky disease (p = 0.009) and advanced disease at diagnosis (p = 0.016). EBV-positive cases did not present a significantly lower OS and PFS in comparison with EBV-negative cases, for all ages and when stratifying for age. When adjusted for covariates, absence of bulky disease at diagnosis (HR: 0.102, 95% CI: 0.02-0.48, p = 0.004) and limited disease stages (I-II) (HR: 0.074, 95% CI: 0.01-0.47, p = 0.006) were associated with a significant better OS. For PFS, limited-disease stages also retained prognostic impact in the multivariate Cox regression (HR: 0.145, 95% CI: 0.04-0.57, p = 0.006). These results are of importance as the early identification of prognostic biomarkers in cHL is critical for guiding and personalizing therapeutic decisions. The prognostic role of EBV in cHL could be modulated by the type of CT protocol employed and interact with the rest of presenting features.

Translational Applications of Artificial Intelligence and Machine Learning for Diagnostic Pathology in Lymphoid Neoplasms: A Comprehensive and Evolutive Analysis.

Genomic analysis and digitalization of medical records have led to a big data scenario within hematopathology. Artificial intelligence and machine learning tools are increasingly used to integrate clinical, histopathological, and genomic data in lymphoid neoplasms. In this study, we identified global trends, cognitive, and social framework of this field from 1990 to 2020. Metadata were obtained from the Clarivate Analytics Web of Science database in January 2021. A total of 525 documents were assessed by document type, research areas, source titles, organizations, and countries. SciMAT and VOSviewer package were used to perform scientific mapping analysis. Geographical distribution showed the USA and People's Republic of China as the most productive countries, reporting up to 190 (36.19%) of all documents. A third-degree polynomic equation predicts that future global production in this area will be three-fold the current number, near 2031. Thematically, current research is focused on the integration of digital image analysis and genomic sequencing in Non-Hodgkin lymphomas, prediction of chemotherapy response and validation of new prognostic models. These findings can serve pathology departments to depict future clinical and research avenues, but also, public institutions and administrations to promote synergies and optimize funding allocation.

Tumores renales sincrónicos: carcinoma renal de células claras y linfoma B de bajo grado, tipo MALT / Synchronous kidney neoplasms: renal carcinoma, clear cells type, and B lymphoma, low grade, MALT type

Introducción: Los linfomas MALT que afectan al riñónson muy raros; siendo la primera descripción la de Pelstringy colaboradores en 1991. Pacientes y métodos: Presentamosun caso de un varón de 71 años al que se le practicó unanefrectomía radical por laparoscopia. En el estudio delriñón se observaron un carcinoma renal, tipo de células claras,y un linfoma B, tipo MALT. Conclusiones: La presenciasimultánea en el riñón de un carcinoma renal y un linfomaMALT es extremadamente rara. Los linfomas MALTque surgen en el riñón podrían estar relacionados con unaenfermedad autoinmune, como el síndrome de Sjögren, ocon la inflamación crónica, como las pielonefritis (AU)

Introduction: Mucosa-associated lymphoid tissue(MALT) lymphoma involving the kidney is extremely rare;and was first reported in 1991 by Pelstring et al. Patientsand methods: We report a case of 71 year-old man underwenta radical nephrectomy by laparos copy. Pathologicalstudy of the kidney revealed a renal cell carcinoma, clearcell type, and a B-cell lymphoma, MALT type. Conclusions:The simultaneous occurrence in the kidney of a renalcarcinoma and MALT lymphoma is extremely rare. MALTlymphoma arising from the kidney could be associated withautoinmune disease such as a Sjögren syndrome or withchronic inflammation, such as pyelonephritis (AU)

Chemokine receptor expression on infiltrating lymphocytes from abdominal aortic aneurysms: role of CXCR4-CXCL12 in lymphoid recruitment.

This is a study to define the profile of chemokine receptors expressed on isolated infiltrating lymphocytes in human abdominal aortic aneurysms (AAAs), and to examine their role in lymphoid recruitment. AAA T-lymphocytes were CXCR4-positive, CCR7-negative and partially CXCR3 and CCR5-positive. Functionally, AAA T-cells were proinflammatory effector cells, as they produced IFN-gamma and granzyme A. AAA B-lymphocytes were CXCR4-positive and exhibited low CXCR5 expression. A relevant feature of infiltrating T- and B-lymphocytes was the high intensity of CXCR4 expression and the capability to migrate to CXCL12. CXCL12-producing cells were found in the adventitia of AAA. These cells were CD45-negative and partially VCAM-1 and DR-positive. In summary, the present results suggest that CXCR4, expressed on infiltrating lymphocytes, and CXCL12, expressed on stromal cells, is involved in the recruitment of lymphocytes within the arterial wall in AAA.

Síndrome de Cronkhite-Canada: una poliposis adquirida y potencialmente reversible / Cronkhite-Canada syndrome: an acquired, potentially reversible polyposis

El síndrome de Cronkhite-Canada es una poliposis no adenomatosa, adquirida e infrecuente que asocia alteraciones ectodérmicas, de la cual desconocemos la etiopatogenia y el manejo terapéutico óptimo. Presentamos un caso de síndrome de Cronkhite-Canada en un varón de 58 años de edad que, tras el tratamiento combinado con corticoides, cromoglicato disódico, loratadina, ciprofloxacino y cinc, obtuvo la remisión clínica y endoscópica parcial. Las lesiones polipoides del síndrome de Cronkhite-Canada pueden revertir con tratamiento médico, por lo que es posible modificar la historia natural de la enfermedad y mejorar su pronóstico

Cronkhite-Canada syndrome is an infrequent, nonadenomatous, acquired polyposis that is associated with ectodermic alterations. The etiopathogenesis and optimal therapeutic management are unknown. We present a case of Cronkhite-Canada syndrome in a 58-year-old man who, after combined treatment with corticosteroids, disodium cromoglycate, loratadine, ciprofloxacin, and zinc, showed complete clinical and partial endoscopic remission. The polypoid lesions of Cronkhite-Canada syndrome can be reversed with medical treatment. Consequently, the natural history of the disease can be modified and its prognosis improved

Gliosarcoma con diferenciación adenoide y fibras de Rosenthal. Presentación de un caso / Gliosarcoma with adenoid differentiation and Rosenthal fibers

Introducción: El gliosarcoma es una variante rara de glioblastoma que se caracteriza por un patrón bifásico en el que alternan áreas de diferenciación glial y mesenquimal. La presencia de alteraciones genéticas idénticas en los componentes glial y sarcomatoso apoya la idea de un origen monoclonal del gliosarcoma. Pacientes y métodos: Presentamos un caso de gliosarcoma con diferenciación adenoide y fibras de Rosenthal. Conclusiones: La existencia de fibras de Rosenthal es un hallazgo muy poco habitual en el seno de tumoraciones gliales de alto grado

Introduction: Gliosarcoma is a rare glioblastoma variant characterized by a biphasic tissue pattern with alternating areas displaying glial and mesenchymal differentiation. The presence of identical genetic alterations in both gliomatous and sarcomatous components strongly supports the concept of a monoclonal origin of gliosarcoma. Patients and methods: We report a case of gliosarcoma with adenoid differentiation and Rosenthal fibers. Conclusions: The presence of Rosenthal fibers is a very uncommon finding in high grade glial neoplasms

[Cronkhite-Canada syndrome: an acquired, potentially reversible polyposis]. / Síndrome de Cronkhite-Canada: una poliposis adquirida y potencialmente reversible.

Cronkhite-Canada syndrome is an infrequent, nonadenomatous, acquired polyposis that is associated with ectodermic alterations. The etiopathogenesis and optimal therapeutic management are unknown. We present a case of Cronkhite-Canada syndrome in a 58-year-old man who, after combined treatment with corticosteroids, disodium cromoglycate, loratadine, ciprofloxacin, and zinc, showed complete clinical and partial endoscopic remission. The polypoid lesions of Cronkhite-Canada syndrome can be reversed with medical treatment. Consequently, the natural history of the disease can be modified and its prognosis improved.

Metástasis de carcinoma ductal de mama sobre carcinoma folicular de tiroides. Presentación de un caso / Metastasis of breast carcinoma to follicular carcinoma of the thyroid gland. Report of a case

Introducción: Las metástasis de tumores sólidos al tiroides son infrecuentes y las metástasis a un tumor tiroideo preexistente aún más raras. Pacientes y métodos: Presentamos el caso de una mujer de 30 años con metástasis de carcinoma de mama sobre un carcinoma folicular de tiroides. Resultados: El proceso metastásico fue diagnosticado como un hallazgo tras la realización de tiroidectomía por diagnóstico clínico de bocio nodular coloide. El estudio histológico mostró focos de carcinoma de mama sobre una proliferación tumoral de folículos tiroideos con invasión de la cápsula (AU)

Introduction: Metastases from solid tumors to thyroid gland are very uncommon findings and metastases to a pre- existing thyroid neoplasm are even more infrequent. Patients and methods: A case of a breast carcinoma metastasizing to a follicular carcinoma of the thyroid gland in a 30-year-old woman is reported. Results: Intratumoral metastasis was diagnosed as an incidental finding in a thyroidectomy specimen clinically diagnosed as nodular colloid goiter. Histological study showed breast carcinoma nests dispersed within a thyroid tumor showing follicular cell differentiation and capsular invasion (AU)

Histiocitoma fibroso maligno de tipo mixoide primario de lengua. Presentación de un caso / Myxoid malignant fibrous histiocytoma of the tongue. Report of a case

Los sarcomas son tumores malignos de partes blandasque representan menos del 1% de los tumores malignos engeneral y son muy infrecuentes en la región oral y maxilofacial.El histiocitoma fibroso maligno (HFM) es un tumorde alto grado incluido en el grupo de los sarcomas de partesblandas. Hasta el momento, sólo se han descrito cuatrocasos de HFM primario en la lengua. Presentamos un nuevocaso de HFM localizado en la lengua, de tipo mixoide.La variante mixoide del HFM parece mostrar un mejor pronóstico

Background: Sarcomas account for less than 1% of allmalignancies and are very unusual in the oral and maxillofacialregion. Malignant fibrous histiocytoma (MFH) is ahigh grade tumor included in the group of soft tissue sarcomas.Only four cases of primary MFH arising in the tonguehave been previously reported. Patients and methods: Acase of myxoid MFH of the tongue is reported. MyxoidMFH has been thought to have a better prognosis than otherMFH types

Carcinoma de células de Merkel. Presentación de un caso con localización atípica / Merkel cell carcinoma. Report of a case with an atypical location

El carcinoma de células de Merkel o carcinoma neuroendocrinocutáneo es un tumor infrecuente, que se caracterizapor su agresividad local y la tendencia a la afectaciónganglionar y a las metástasis a distancia. Se origina a partirde células que pertenecen al sistema neuroendocrino, por loque presentan expresión de determinados marcadores inmunohistoquímicos.Presentamos el caso de un varón con unalesión cutánea en una localización atípica (pretibial), dondela expresión de marcadores neuroendocrinos y la presenciade gránulos en el estudio ultraestructural facilitaron el diagnósticodiferencial con otras entidades. Un diagnóstico precozy un tratamiento adecuado son importantes para mejorarel pronóstico de estos enfermos

Merkel cell carcinoma or neuroendocrine carcinoma ofthe skin is a highly malignant uncommon neoplasm, withearly regional lymph node involvement and distant metastases.It arises from cells belonging to the neuroendocrinesystem, therefore presenting a distinct immunohistochemicalprofile. We report a case of a male with a cutaneouslesion located in an atypical anatomical site (pretibial). Thediagnosis was confirmed by immunohistochemical stainingand by the presence of dense core granules in electronmicroscopy. An early diagnosis and a correct treatment areimportant to improve the prognosis of these patients

Carcinoma de mama metastático en ganglios axilares con linfoma no Hodgkin. Presentación de un caso / Concurrent metastatic breast carcinoma and malignant lymphoma in lymph nodes. Report of a case

La larga supervivencia de pacientes diagnosticados de neoplasia maligna tras exitosos tratamientos ha incrementado la aparición de segundas neoplasias. Presentamos un caso de una mujer de 74 años con un carcinoma ductal infiltrante de mama. Todos los ganglios linfáticos axilares estaban ampliamente afectados por linfoma no Hodgkin, y 2 ganglios linfáticos mostraron metástasis de carcinoma. El interés de nuestro caso radica en la coexistencia de ambos tumores en los ganglios linfáticos axilares

The long survival of patients diagnosed with malignant neoplasm after successful treatments has increased the incidence of second neoplasms. We report a case of a 74-year-old woman with an invasive ductal breast carcinoma. All axillary lymph nodes were extensively affected by non-Hodgkin’s lymphoma, and two lymph nodes demonstrated metastatic carcinoma. The interest of our case resides in the coexistence of both tumors in the axillary lymph nodes

Quiste epidermoide esplénico. Presentación de un caso / Epidermoid splenic cyst. Report of a case

Los quistes no parasitarios son una enfermedad infrecuente en el bazo. Presentamos un caso de una joven de 19 años con adenopatías generalizadas en la que se sospechaba un linfoma. El estudio ecográfico mostró la existencia de una lesión ocupante de espacio esplénica. La paciente se sometió a una esplenectomía total, en la que se diagnosticó un quiste epidermoide. Revisamos las características histopatológicas de los quistes esplénicos y las alternativas terapéuticas más recientes

Splenic non-parasitic cysts are infrequent. We report a case of a 19-years-old girl with lymphadenopathy suspected of having a lymphoma. Ultrasonography revealed a lesion in the spleen. The patient underwent splenectomy and an epidermoid cyst was found. Histopathologic features of the splenic cysts and the more recent treatments are reviewed

Carcinoma de mama metastásico en ganglios axilares con linfoma no Hodgkin. Presentación de un caso / Concurrent metastatic breast carcinoma and malignant lymphoma in lymph nodes. Report of a case

La larga supervivencia de pacientes diagnosticados de neoplasia maligna tras exitosos tratamientosha incrementado la aparición de segundas neoplasias. Presentamos un caso de unamujer de 74 años con un carcinoma ductal infiltrante de mama. Todos los ganglios linfáticos axilaresestaban ampliamente afectados por linfoma no Hodgkin, y 2 ganglios linfáticos mostraronmetástasis de carcinoma. El interés de nuestro caso radica en la coexistencia de ambos tumoresen los ganglios linfáticos axilares

The long survival of patients diagnosed with malignant neoplasm after successful treatmentshas increased the incidence of second neoplasms. We report a case of a 74-year-old womanwith an invasive ductal breast carcinoma. All axillary lymph nodes were extensively affected bynon-Hodgkin’s lymphoma, and two lymph nodes demonstrated metastatic carcinoma. The interestof our case resides in the coexistence of both tumors in the axillary lymph nodes

Quiste epidermoide esplénico. Presentación de un caso / Epidermoid splenic cyst. Report of a case

Los quistes no parasitarios son una enfermedad infrecuente en el bazo. Presentamos uncaso de una joven de 19 años con adenopatías generalizadas en la que se sospechaba un linfoma.El estudio ecográfico mostró la existencia de una lesión ocupante de espacio esplénica.La paciente se sometió a una esplenectomía total, en la que se diagnosticó un quiste epidermoide.Revisamos las características histopatológicas de los quistes esplénicos y las alternativasterapéuticas más recientes

Splenic non-parasitic cysts are infrequent. We report a case of a 19-years-old girl with lymphadenopathysuspected of having a lymphoma. Ultrasonography revealed a lesion in the spleen.The patient underwent splenectomy and an epidermoid cyst was found. Histopathologic featuresof the splenic cysts and the more recent treatments are reviewed

Characterisation of T and B lymphocytes infiltrating abdominal aortic aneurysms.

Cellular infiltrates consisting mainly of lymphocytes are commonly present in the arterial wall in abdominal aortic aneurysm (AAA). However, despite this, the precise nature of these populations has to date not been described in detail. The aim of this study was to perform an exhaustive phenotypic characterisation of the infiltrating lymphocytes in order to define the inflammatory process that develops in AAA. For this purpose, AAA-infiltrating lymphocytes from 25 fresh aneurysm wall samples and, as a control, peripheral blood (PB) lymphocytes from the same patients were purified. The expression of lineage specific markers, maturation molecules, activation antigens and adhesion molecules on T and B lymphocytes was examined by triple-colour immunofluorescence and flow cytometry analysis. The phenotype of AAA-infiltrating lymphocytes was compared with that of PB of the patients with AAA. The results reveal that AAA-infiltrating B and T lymphocytes consist of activated memory cells, with specific homing properties. In addition, they express molecules of B-T co-stimulation and, occasionally, exhibit phenotypical features indicative of the ectopic formation of lymphoid structures. These findings are discussed in the light of the similarities shared with the lymphoid infiltration occurring in other chronic autoimmune/inflammatory disorders.