While sickle cell anemia (SCA) and hereditary spherocytosis (HS) share common features of increased spleen erythrophagocytosis due to increased red blood cell (RBC) turnover, SCA is specifically characterized by susceptibility to infections. In this study, histological lesions in the spleens of pediatric patients with SCA were analyzed, in close correlation with past clinical history and comparatively to HS, healthy and transfused β-thalassemia patients (TDT). An evaluation of red pulp elementary lesions (red pulp fibrosis, iron deposition, number of Gandy-Gamna, and RBC trapping) combined into a severity score was established, as well as B-cell follicles analysis. Quantification on digitalized slides of iron deposition, RBC trapping, and red pulp fibrosis was additionally performed. Spleens from 22 children with SCA, eight with HS, eight with TDT, and three healthy controls (HC) were analyzed. Median age at splenectomy was not different between SCA and HS patients, 6.05 years (range: 4.5-16.0) versus 4.75 (range: 2.2-9.5). Marked heterogeneity was found in SCA spleens in contrast to other conditions. Contrary to previous reports, B-cell follicles were generally preserved in SCA. While RBC trapping was significantly increased in both SCA and HS (compared to TDT and HC), quantitative fibrosis and overall red pulp severity score were significantly increased in SCA spleens compared to other conditions. Moreover, there was an inverse correlation between quantitative fibrosis and number of B-cell follicles, linking these two compartments as well as spleen fibrosis to infectious susceptibility in SCA, potentially through impaired red pulp macrophage scavenging and B-cell subpopulations defects.

A new classification of lymphoma has been published in 2001 under the direction of the World Health Organisation. This classification is based on a consensus between experts in haematopathology, haematology and oncology involved in management of lymphoma. Around 40 entities are described on the basis of morphology, immunophenotype, genetic and clinical presentation. Lymphomas and lymphoid leukaemias are gathered because tumour masses and leukaemic phases are present in numerous entities. This classification differentiates B-cell lymphomas from T/NK (natural killer) cell lymphomas. Grading the different lymphomas into low grade or high grade is no more required in this classification.

Large and systematic studies of non-Hodgkin lymphoma (NHL) in the Far East (FE) with good comparative data are scarce in the literature. In this study, five expert hematopathologists classified 730 consecutive cases of newly-diagnosed NHL from four sites in the FE (excluding Japan) using the World Health Organization classification. The results were compared to 399 cases from North America (NA). We found a significantly higher male to female ratio in the FE compared to NA (1.7 versus 1.1; p < 0.05). The median ages of patients with low-grade (LG) and high-grade (HG) B-NHL in the FE (58 and 51 years, respectively) were significantly lower than in NA (64 and 68 years, respectively). The FE had a significantly lower relative frequency of B-NHL and a higher frequency of T-NHL (82 vs. 18 %) compared to NA (90.5 vs. 9.5 %). Among mature B cell lymphomas, the FE had a significantly higher relative frequency of HG B-NHL (54.8 %) and a lower frequency of LG B-NHL (27.2 %) than NA (34.3 and 56.1 %, respectively). Diffuse large B cell lymphoma was more common in the FE (49.4 %) compared to NA (29.3 %), whereas the relative frequency of follicular lymphoma was lower in the FE (9.4 %) compared to NA (33.6 %). Among T-NHL, nasal NK/T cell NHL was more frequent in the FE (5.2 %) compared to NA (0 %). Peripheral T cell lymphoma was also more common in the FE (9.1 %) than in NA (5.3 %). Further epidemiologic studies are needed to better understand the pathobiology of these differences.

The distribution of non-Hodgkin lymphoma subtypes varies around the world, but a large systematic comparative study has never been done. In this study, we evaluated the clinical features and relative frequencies of non-Hodgkin lymphoma subtypes in five developing regions of the world and compared the findings to the developed world. Five expert hematopathologists classified 4848 consecutive cases of lymphoma from 26 centers in 24 countries using the World Health Organization classification, and 4539 (93.6%) were confirmed to be non-Hodgkin lymphoma, with a significantly greater number of males than females in the developing regions compared to the developed world (P<0.05). The median age at diagnosis was significantly lower for both low- and high-grade B-cell lymphoma in the developing regions. The developing regions had a significantly lower frequency of B-cell lymphoma (86.6%) and a higher frequency of T- and natural killer-cell lymphoma (13.4%) compared to the developed world (90.7% and 9.3%, respectively). Also, the developing regions had significantly more cases of high-grade B-cell lymphoma (59.6%) and fewer cases of low-grade B-cell lymphoma (22.7%) compared to the developed world (39.2% and 32.7%, respectively). Among the B-cell lymphomas, diffuse large B-cell lymphoma was the most common subtype (42.5%) in the developing regions. Burkitt lymphoma (2.2%), precursor B- and T-lymphoblastic leukemia/lymphoma (1.1% and 2.9%, respectively) and extranodal natural killer/T-cell lymphoma (2.2%) were also significantly increased in the developing regions. These findings suggest that differences in etiologic and host risk factors are likely responsible, and more detailed epidemiological studies are needed to better understand these differences.

Comparative data on the distribution of non-Hodgkin lymphoma (NHL) subtypes in Southern Africa (SAF) is scarce. In this study, five expert haematopathologists classified 487 consecutive cases of NHL from SAF using the World Health Organization classification, and compared the results to North America (NA) and Western Europe (WEU). Southern Africa had a significantly lower proportion of low-grade (LG) B-NHL (34·3%) and a higher proportion of high-grade (HG) B-NHL (51·5%) compared to WEU (54·5% and 36·4%) and NA (56·1% and 34·3%). High-grade Burkitt-like lymphoma was significantly more common in SAF (8·2%) than in WEU (2·4%) and NA (2·5%), most likely due to human immunodeficiency virus infection. When SAF patients were divided by race, whites had a significantly higher frequency of LG B-NHL (60·4%) and a lower frequency of HG B-NHL (32·7%) compared to blacks (22·5% and 62·6%), whereas the other races were intermediate. Whites and other races had a significantly higher frequency of follicular lymphoma and a lower frequency of Burkitt-like lymphoma compared to blacks. The median ages of whites with LG B-NHL, HG B-NHL and T-NHL (64, 56 and 67 years) were significantly higher than those of blacks (55, 41 and 34 years). Epidemiological studies are needed to better understand these differences.

SummaryThe distribution of non‐Hodgkin lymphoma (NHL) subtypes varies around the world, but a systematic study of South‐eastern Europe (SEEU) has never been done. Therefore, we evaluated the relative frequencies of NHL subtypes in three SEEU countries – Croatia, Romania and Macedonia. Five expert haematopathologists reviewed 632 consecutive cases of newly diagnosed NHL from the three SEEU countries using the World Health Organization classification. The results were compared to 399 cases from North America (NA) and 580 cases from Western Europe (WEU). The proportions of B‐ and T‐cell NHL and the sex distribution in SEEU were similar to WEU and NA. However, the median ages of patients with low‐ and high‐grade B‐NHL in SEEU (60 and 59 years, respectively) were significantly lower than in NA (64 and 68 years, respectively; P < 0·05). SEEU had a significantly lower proportion of low‐grade B‐NHL (46·6%) and higher proportion of high‐grade B‐NHL (44·5%) compared to both WEU (54·5% and 36·4%, respectively) and NA (56·1% and 34·3%, respectively). There were no significant differences in the relative frequencies of T‐NHL subtypes. This study provides new insights into differences in the relative frequencies of NHL subtypes in different geographic regions. Epidemiological studies are needed to better characterize and explain these differences.

Le terme d’histiocytose désigne l’accumulation pathologique d’histiocytes dans un tissu ou un organe. La rate est l’un des organes où les histiocytoses sont fréquentes. Elles réalisent une splénomégalie. Le diagnostic repose sur l’étude des signes cliniques et biologiques. Les techniques d’imagerie montrent si le parenchyme est infiltré de façon diffuse ou s’il existe des masses. Souvent une splénectomie d’intérêt diagnostique est proposée. L’examen anatomo-pathologique apporte des éléments majeurs pour le diagnostic en particulier grâce à la morphologie et à l’immunophénotype (expression de CD68 et CD 163), pour le diagnostic de l’affection responsable et la prise en charge thérapeutique.

Comparative data regarding the distribution of non-Hodgkin lymphoma (NHL) subtypes in North Africa, the Middle East and India (NAF/ME/IN) is scarce in the literature. In this study, we evaluated the relative frequencies of NHL subtypes in this region. Five expert haematopathologists classified 971 consecutive cases of newly-diagnosed NHL from five countries in NAF/ME/IN. After review, 890 cases (91·7%) were confirmed to be NHL and compared to 399 cases from North America (NA). The male-to-female ratio was significantly higher in NAF/ME/IN (1·8) compared to NA (1·1; P< 0·05). The median ages of patients with low-grade (LG) and high-grade (HG) B-NHL in NAF/ME/IN (56 and 52 years, respectively) were significantly lower than in NA (64 and 68 years, respectively). In NAF/ME/IN, a significantly lower proportion of LG B-NHL (28·4%) and a higher proportion of HG B-NHL (58·4%) were found compared to NA (56·1% and 34·3%, respectively). Diffuse large B-cell lymphoma was more common in NAF/ME/IN (49·4%) compared to NA (29·3%), whereas follicular lymphoma was less common in NAF/ME/IN (12·4%) than in NA (33·6%). In conclusion, we found significant differences in NHL subtypes and clinical features between NAF/ME/IN and NA. Epidemiological studies are needed to better understand the pathobiology of these differences.

The relative distribution of non-Hodgkin lymphoma (NHL) subtypes differs markedly around the world. The aim of this study was to report this distribution in Algeria. A panel of four hematopathologists classified 197 consecutive cases according to the World Health Organization classification, including 87.3% B-cell and 12.7% T- or natural killer (NK)-cell NHLs. This series was compared with similar cohorts from Western Europe (WEU) and North America (NA). Algeria had a significantly higher frequency of diffuse large B-cell lymphoma (DLBCL: 52.8%) and a lower frequency of follicular lymphoma (FL: 13.2%) compared with WEU (DLBCL: 32.2%; FL: 20.0%) and NA (DLBCL: 29.3%; FL: 33.6%). The frequency of mantle cell lymphoma was lower in Algeria (2.5%) compared with WEU (8.3%). Smaller differences were also found among the NK/T-cell lymphomas. In conclusion, we found important differences between Algeria and Western countries, and further epidemiologic studies are needed to explain these differences.

Le myélolipome est une lésion bénigne se développant habituellement dans les glandes surrénales ou dans divers sites extra surrénaliens. Un seul cas de localisation intra splénique chez l’homme a été signalé dans la littérature internationale. Nous rapportons ici deux cas exceptionnels de myélolipome intra splénique chez deux femmes de 65 et 67 ans découvert devant une splénomégalie isolée. Les deux rates enlevées étaient le siège de masses arrondies constituées de pulpe rouge contenant des foyers d’hématopoïèse extra médullaire (Hem) et des plages de tissu adipeux ressemblant à un tissu médullaire osseux. Des foyers d’Hem se développaient dans la pulpe rouge entourant les masses pseudo tumorales. Tous ces foyers d’Hem étaient constitués d’érythroblastes et de cellules granulocytaires à différents stades de maturation normale et de rares mégacaryocytes sans cellules blastiques. Les relations de ces myélolipomes intra spléniques avec les autres myélolipomes extra surrénaliens sont discutées ainsi que le diagnostic différentiel avec les Hem intra spléniques néoplasiques ou non néoplasiques.

The distribution of subtypes of non-Hodgkin lymphoma (NHL) in Latin America is not well known. This Chilean study included 207 consecutive cases of NHL diagnosed at five cancer centers in the capital, Santiago, and one center in Viña del Mar. All cases were reviewed and classified independently by five expert hematopathologists according to the 2001 World Health Organization classification of NHL. A consensus diagnosis of NHL was reached in 195 of the 207 cases (94%). B-cell lymphomas constituted 88% of NHL, and diffuse large B-cell lymphoma (DLBCL, 38.5%) and follicular lymphoma (25.1%) were the most common subtypes. There was a high frequency of marginal zone B-cell lymphoma (10.3%), as well as of extranodal natural killer (NK)/T-cell lymphoma, nasal type (2.6%) and adult T-cell leukemia/lymphoma (0.5%). Extranodal presentation was seen in 74 of the 195 cases (38%) and the most common extranodal presentation was in the stomach (37.6%). The most common gastric lymphoma was DLBCL (54.5%) followed by mucosa-associated lymphoid tissue (MALT) lymphoma (41%). Overall, the frequency of NHL subtypes in Chile is between that reported in Western and Eastern countries, which is probably a reflection of the admixture of ethnicities as well as the environment and socioeconomic status of its population.

The distribution of non-Hodgkin lymphoma (NHL) subtypes differs around the world but a systematic study of Latin America has not been done. Therefore, we evaluated the relative frequencies of NHL subtypes in Central and South America (CSA). Five expert hematopathologists classified consecutive cases of NHL from 5 CSA countries using the WHO classification and compared them to 400 cases from North America (NA). Among the 1028 CSA cases, the proportions of B- and T-cell NHL and the sex distribution were similar to NA. However, the median age of B-cell NHL in CSA (59 years) was significantly lower than in NA (66 years; P < .0001). The distribution of high-grade (52.9%) and low-grade (47.1%) mature B-cell NHL in CSA was also significantly different from NA (37.5% and 62.5%; P < .0001). Diffuse large B-cell lymphoma was more common in CSA (40%) than in NA (29.2%; P < .0001), whereas the frequency of follicular lymphoma was similar in Argentina (34.1%) and NA (33.8%), and higher than the rest of CSA (17%; P < .001). Extranodal NK/T-cell NHL was also more common in CSA (P < .0001). Our study provides new objective evidence that the distribution of NHL subtypes varies significantly by geographic region and should prompt epidemiologic studies to explain these differences.

Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA; Center for Collaboration on Research, Design and Analysis, College of Public Health, University of Nebraska Medical Center, Omaha, NE, USA; Department of Anatomic Pathology and Cytology, Hotel Dieu, Paris, France; Section of Pathology and Leeds Institute of Molecular Medicine, St James University Hospital, Leeds, UK; Institute of Pathology, University of Würzburg, Würzburg, Germany; Department of Pathology, Cedars-Sinai Medical Center and University of Southern California Keck School of Medicine, Los Angeles, CA, USA Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA;

La glande mammaire peut être le siège d’un lymphome primitif ou être envahie secondairement par un lymphome d’un autre organe. L’atteinte est habituellement unilatérale, plus rarement bilatérale. Chez l’homme cette pathologie reste exceptionnelle. Primitifs ou secondaires, ce sont pratiquement les mêmes variétés de lymphomes qui sont observées. Il s’agit essentiellement de lymphomes de type B, ceux de type NK/T restant rares en Occident. Les plus fréquents sont les lymphomes diffus à grandes cellules B, qui, lorsqu’ils sont primitifs, présentent la particularité de donner des rechutes sous forme d’extension au système nerveux central. Beaucoup moins fréquentes sont les localisations de lymphomes à petites cellules B, de type surtout folliculaire ou de la zone marginale dite MALT. Un petit nombre parmi ces derniers peut être associé à une amyloïdose. Ces dernières années, une association particulière a fait l’objet de plusieurs publications, celle de lymphomes T à grandes cellules anaplasiques, ALK négatif se présentant comme un lymphome primitif, survenant au contact d’une prothèse mammaire en silicone entourée de réactions inflammatoires chroniques et souvent d’un épanchement liquide appelé « sérome ». La chirurgie d’exérèse n’est pas indiquée dans le traitement de ces lymphomes, qui repose essentiellement sur chimiothérapie et immunothérapie, avec traitement prophylactique des localisations dans le système nerveux central des lymphomes à grandes cellules B.