Subject(s)
COVID-19 , Chilblains , Interferon Type I , Humans , Chilblains/diagnosis , Chilblains/etiology , Chilblains/epidemiology , SARS-CoV-2 , PandemicsABSTRACT
CASE: A 11-year-old boy with no medical history presented with a protective limp and worsening mechanical pain in his left knee. No recent traumatic or infectious history was reported. Radiographs and ultrasonography showed multiple intra-articular loose bodies with osteocartilaginous signal. Dysplasia epiphysealis hemimelica (DEH) was confirmed by magnetic resonance imaging (MRI) and computed tomography (CT) scan. This is the first report that describes the presence of loose bodies in a knee without previous surgery as a possible case of DEH. CONCLUSION: We emphasize the use of CT scan and MRI before any surgical procedure when intra-articular loose bodies are unexpectedly discovered.
Subject(s)
Bone Diseases, Developmental , Bone Diseases, Developmental/diagnostic imaging , Bone Diseases, Developmental/pathology , Bone Diseases, Developmental/surgery , Child , Femur/abnormalities , Femur/surgery , Humans , Knee Joint/surgery , Male , Tibia/abnormalities , Tibia/surgeryABSTRACT
BACKGROUND: Since 2010, nationwide networks of reference centers for sarcomas (RREPS/NETSARC/RESOS) collected and prospectively reviewed all cases of sarcomas and connective tumors of intermediate malignancy (TIM) in France. METHODS: The nationwide incidence of sarcoma or TIM (2013-2016) was measured using the 2013 WHO classification and confirmed by a second independent review by expert pathologists. Simple clinical characteristics, yearly variations and correlation of incidence with published clinical trials are presented and analyzed. RESULTS: Over 150 different histological subtypes are reported from the 25172 patients with sarcomas (n = 18712, 74,3%) or TIM (n = 6460, 25.7%), with n = 5838, n = 6153, n = 6654, and n = 6527 yearly cases from 2013 to 2016. Over these 4 years, the yearly incidence of sarcomas and TIM was therefore 70.7 and 24.4 respectively, with a combined incidence of 95.1/106/year, higher than previously reported. GIST, liposarcoma, leiomyosarcomas, undifferentiated sarcomas represented 13%, 13%, 11% and 11% of tumors. Only GIST, as a single entity had a yearly incidence above 10/106/year. There were respectively 30, 64 and 66 different histological subtypes of sarcomas or TIM with an incidence ranging from 10 to 1/106, 1-0.1/106, or < 0.1/106/year respectively. The 2 latter incidence groups represented 21% of the patients with 130 histotypes. Published phase III and phase II clinical trials (p<10-6) are significantly higher with sarcomas subtypes with an incidence above 1/106 per. CONCLUSIONS: This nationwide registry of sarcoma patients, with exhaustive histology review by sarcoma experts, shows that the incidence of sarcoma and TIM is higher than reported, and that tumors with a very low incidence (1<106/year) are less likely to be included in clinical trials.
Subject(s)
Sarcoma/epidemiology , Sarcoma/pathology , Adolescent , Adult , Aged , Female , France/epidemiology , Humans , Incidence , Male , Middle Aged , Neoplasm Grading , Prospective Studies , Sarcoma/classification , Sarcoma/diagnosis , World Health Organization , Young AdultABSTRACT
Pericytic tumors encompass several entities sharing morphologic and immunohistochemical features. A subset of perivascular myoid tumors associated with the SRF-RELA fusion gene was previously described. Herein, we report a series of 13 tumors belonging to this group, in which we have identified new fusion genes by RNA-sequencing, thus expanding the molecular spectrum of this entity. All patients except 1 were children and infants. The tumors, frequently located in the head (n=8), had a mean size of 38 mm (range 10 to 150 mm) and were mostly (n=9) well-circumscribed. Exploration of the follow-up data (ranging from 3 to 68 mo) confirmed the benign behavior of these tumors. These neoplasms presented a spectrum of morphologies, ranging from perivascular patterns to myoid appearance. Tumor cells presented mitotic figures but without marked atypia. Some of these tumors could mimic sarcoma. The immunohistochemical profiles confirmed a pericytic differentiation with the expression of the smooth muscle actin and the h-caldesmon, as well as the frequent positivity for pan-cytokeratin. The molecular analysis identified the expected SRF-RELA fusion gene, in addition to other genetic alterations, all involving SRF fused to CITED1, CITED2, NFKBIE, or NCOA2. The detection of SRF-NCOA2 fusions in spindle cell rhabdomyosarcoma of the infant has previously been described, representing a risk of misdiagnosis, although the cases reported herein did not express MyoD1. Finally, clustering analyses confirmed that this group of SRF-fused perivascular myoid tumors forms a distinct entity, different from other perivascular tumors, spindle cell rhabdomyosarcomas of the infant, and smooth muscle tumors.
Subject(s)
Biomarkers, Tumor/genetics , Gene Fusion , Neoplasms, Connective and Soft Tissue/genetics , Serum Response Factor/genetics , Transcription Factor RelA/genetics , Adolescent , Aged , Apoptosis Regulatory Proteins/genetics , Child , Child, Preschool , England , Female , France , Humans , I-kappa B Proteins/genetics , Male , Neoplasms, Connective and Soft Tissue/pathology , Nuclear Receptor Coactivator 2/genetics , Proto-Oncogene Proteins/genetics , Repressor Proteins/genetics , Trans-Activators/geneticsABSTRACT
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
ABSTRACT
NFATc2-rearranged sarcomas (NFATc2-Sarcomas) are infrequent round cell tumors characterized by EWSR1-NFATc2 fusions and FUS-NFATc2 fusions. Although our knowledge on these neoplasms has increased recently, novel diagnostic tools and more comprehensive series are still needed. Here, we describe the features of a series of seven molecularly confirmed NFATc2-Sarcomas (EWSR1-NFATc2, n = 4; FUS-NFATc2, n = 3) and demonstrate the utility of AGGRECAN immunohistochemistry for their identification. Patients were four males and three females, ranging in age from 19 to 66 years (median: 33). All were primary bone tumors (femur, n = 4; tibia, n = 2; ilium, n = 1), frequently infiltrating the surrounding soft tissues. Treatment often consisted of neoadjuvant chemotherapy and surgery. Follow-up was available for six patients (median 18 months, range 5-102 months), three patients died of disease and four patients are currently alive. Histologically, tumors consisted of monotonous round cells growing in lobules and sheets in variable amounts of fibrous to myxoid stroma. Other findings included spindle cells, corded and trabecular architecture, nuclear pleomorphism, cartilaginous differentiation, and osteoid-like matrix. Histological response to neoadjuvant chemotherapy was poor in all resection specimens available for review (n = 4). Tumors were diffusely positive for AGGRECAN and CD99 (7/7), and a subset expressed Pan-Keratin (AE1-AE3; 3/6), S100 (2/6), BCOR (2/6), ETV-4 (2/5), WT1 (2/6), and ERG (2/5). Desmin, NKX3-1, and SATB2 were negative (0/6). Diffuse AGGRECAN staining was also seen in 8/129 round cell sarcomas used for comparison, including mesenchymal chondrosarcoma (7/26) and CIC-sarcoma (1/26). Array-CGH showed complex karyotypes with recurrent deletions of tumor suppressor genes (CDKN2A/B, TUSC7, and DMD) in three FUS-NFATC2 cases and a simpler profile without homozygous losses in one EWSR1-NFATc2 case. Segmental chromosomal gains covering the loci of the fusion genes were detected in both variants. Overall, our study confirms and expands previous observations on NFATc2-sarcomas and supports that AGGRECAN is a useful biomarker of these tumors.
Subject(s)
Aggrecans/metabolism , Biomarkers, Tumor/metabolism , Bone Neoplasms/diagnosis , NFATC Transcription Factors/genetics , Sarcoma/diagnosis , Adult , Aged , Bone Neoplasms/genetics , Bone Neoplasms/metabolism , Female , Humans , Male , Middle Aged , Oncogene Fusion , Oncogene Proteins, Fusion/genetics , Sarcoma/genetics , Sarcoma/metabolismABSTRACT
In recent years, undifferentiated small round cell sarcomas (USRCSs) have been divided into a variety of new, rare, sarcoma subtypes, including the group of Ewing-like sarcomas, which have the morphological appearance of Ewing sarcomas, but carry CIC-DUX4, BCOR-CCNB3 and other gene fusions different from the classic EWSR1-ETS gene fusion. Using high-throughput RNA-sequencing (RNA-seq) analyses, we identified a novel recurrent gene fusion, CRTC1-SS18, in two cases of USRCS that lacked any known translocation. RNA-seq results were confirmed by reverse transcription polymerase chain reaction, long-range polymerase chain reaction, and fluorescence in situ hybridization. In vitro, we showed that the cells expressing the gene fusion were morphologically distinct and had enhanced oncogenic potential as compared with control cells. Expression profile comparisons with tumours of other sarcoma subtypes demonstrated that both cases clustered close to EWSR1-CREB1-positive tumours. Moreover, these analyses indicated enhanced NTRK1 expression in CRTC1-SS18-positive tumours. We conclude that the novel gene fusion identified in this study adds a new subtype to the USRCSs with unique gene signatures, and may be of therapeutic relevance. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Subject(s)
Biomarkers, Tumor/genetics , Cell Differentiation , Gene Fusion , Proto-Oncogene Proteins/genetics , Repressor Proteins/genetics , Sarcoma, Small Cell/genetics , Soft Tissue Neoplasms/genetics , Transcription Factors/genetics , Adult , Biomarkers, Tumor/analysis , Biomarkers, Tumor/metabolism , Cell Movement , Cell Proliferation , Female , Genetic Predisposition to Disease , HEK293 Cells , Humans , Male , Molecular Diagnostic Techniques , Neoplasm Invasiveness , Phenotype , Proto-Oncogene Proteins/metabolism , Repressor Proteins/metabolism , Sarcoma, Small Cell/metabolism , Sarcoma, Small Cell/pathology , Sarcoma, Small Cell/therapy , Soft Tissue Neoplasms/metabolism , Soft Tissue Neoplasms/pathology , Soft Tissue Neoplasms/therapy , Transcription Factors/metabolismABSTRACT
UNLABELLED: : Osteoarthritis (OA) is the most widespread musculoskeletal disorder in adults. It leads to cartilage damage associated with subchondral bone changes and synovial inflammation, causing pain and disability. The present study aimed at evaluating the safety of a dose-escalation protocol of intra-articular injected adipose-derived stromal cells (ASCs) in patients with knee OA, as well as clinical efficacy as secondary endpoint. A bicentric, uncontrolled, open phase I clinical trial was conducted in France and Germany with regulatory agency approval for ASC expansion procedure in both countries. From April 2012 to December 2013, 18 consecutive patients with symptomatic and severe knee OA were treated with a single intra-articular injection of autologous ASCs. The study design consisted of three consecutive cohorts (six patients each) with dose escalation: low dose (2 × 10(6) cells), medium dose (10 × 10(6)), and high dose (50 × 10(6)). The primary outcome parameter was safety evaluated by recording adverse events throughout the trial, and secondary parameters were pain and function subscales of the Western Ontario and McMaster Universities Arthritis Index. After 6 months of follow-up, the procedure was found to be safe, and no serious adverse events were reported. Four patients experienced transient knee joint pain and swelling after local injection. Interestingly, patients treated with low-dose ASCs experienced significant improvements in pain levels and function compared with baseline. Our data suggest that the intra-articular injection of ASCs is a safe therapeutic alternative to treat severe knee OA patients. A placebo-controlled double-blind phase IIb study is being initiated to assess clinical and structural efficacy. SIGNIFICANCE: Although this phase I study included a limited number of patients without a placebo arm, it showed that local injection of autologous adipose-derived stem cells was safe and well tolerated in patients with knee osteoarthritis. This study also provides encouraging preliminary evidence of efficacy. Larger and controlled long-term studies are now mandatory to confirm whether this new strategy of cell therapy can improve pain and induce structural benefit in osteoarthritis.
Subject(s)
Adipose Tissue/cytology , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells/cytology , Osteoarthritis, Knee/therapy , Adipose Tissue/transplantation , Aged , Cell Count , Female , Humans , Injections, Intra-Articular , Male , Mesenchymal Stem Cell Transplantation/adverse effects , Mesenchymal Stem Cell Transplantation/methods , Middle Aged , Osteoarthritis, Knee/pathology , Severity of Illness Index , Treatment OutcomeABSTRACT
Cutaneous clear cell hidradenoma is an uncommon benign adnexal tumor which is not supposed to metastasize, contrary to its rare malignant counterpart, hidradenocarcinoma. We report the case of a 49-year-old man, who had had a stable inguinal lymph node enlargement for 6 years. An excision was performed and revealed an intra-nodal tumor, made of large clear cells with abundant cytoplasm and round nuclei without atypia or mitosis. The immunohistochemical staining showed diffuse positivity for keratin AE1/AE3, keratin 5/6 and p63, and focal staining with keratin 7, epithelial membrane antigen (EMA) and carcinous epithelial antigen (CEA), which underlined some ductular structures. Tumor cells were negative for renal markers PAX8 and CD10. Ki67 stained less than 1% of tumor cells. A translocation involving MAML2 gene was evidenced by fluorescence in situ hybridization (FISH) analysis. No primary cutaneous tumor was found after extensive examination. Altogether, these results are in favor of an isolated nodal hidradenoma, for which we discuss two hypothesis: a primary nodal lesion, or a 'benign metastasis' of a cutaneous tumor. Cases of morphologically benign hidradenoma with lymph node involvement are exceptional. Our case, similar to every other reported case, was associated with an excellent prognosis, supporting the idea that these patients should not be overtreated.
Subject(s)
Acrospiroma/pathology , Lymph Nodes/pathology , Sweat Gland Neoplasms/pathology , Acrospiroma/genetics , Biomarkers, Tumor/analysis , DNA-Binding Proteins/genetics , Humans , Immunohistochemistry , In Situ Hybridization, Fluorescence , Male , Middle Aged , Nuclear Proteins/genetics , Sweat Gland Neoplasms/genetics , Trans-Activators , Transcription Factors/genetics , Translocation, GeneticABSTRACT
GNAS (guanine nucleotide-binding protein/α-subunit) mutations that induce the activation of G-protein α-subunit participate in the pathogenesis of fibrous dysplasia. The aim of this study was to evaluate the sensitivity and specificity of GNAS mutations in fibrous dysplasia and other fibro-osseous lesions, to assess the value of investigating this mutation in the diagnosis of fibro-osseous lesions. We studied 91 cases of fibrous dysplasia. The quality and/or quantity of genomic DNA were suitable for molecular analysis for 51 cases of fibrous dysplasia. GNAS mutations were investigated by three techniques: high-resolution melting (exon 8), allele-specific PCR (exons 8 and 9) and/or direct DNA sequencing (exons 8 and 9). Fibrous dysplasia samples were classified blind to the GNAS mutation status into six histological subtypes as conventional, fibro-involutive, osteosclerosing, cementifying, osteocartilaginous and with prominent aneurysmal cystic changes. We also studied 14 cases of low-grade osteosarcoma, 21 cases of ossifying fibroma, 3 cases of osteofibrous dysplasia, 1 case of osseous dysplasia of the jawbone and 1 post-traumatic lesion of the ribs. Twenty-three cases of fibrous dysplasia (45%) showed mutations of codon 201 (exon 8, p.R201H or p.R201C). No mutation was found on codon 227 (exon 9). GNAS mutations in conventional fibrous dysplasia were detected in the same proportion (47%) as in the other histological subtypes (47%, P=0.96), regardless of sex (P=0.44), age (P=0.90) and location (P=1). GNAS mutations were not detected in any other fibro-osseous lesions. The GNAS mutation was thus specific to fibrous dysplasia in the context of fibro-osseous lesions. The particular mosaicism of mutant and non-mutant cells within the lesion or the existence of other mutations not already described could explain the lack of GNAS mutation in cases of fibrous dysplasia. Investigating this mutation may constitute a valuable complementary diagnostic tool, despite its low sensitivity, particularly in unconventional morphologically different subtypes of fibrous dysplasia.
Subject(s)
Biomarkers/analysis , Bone Diseases, Developmental/genetics , GTP-Binding Protein alpha Subunits, Gs/genetics , Mutation , Adolescent , Adult , Bone Neoplasms/genetics , Child , Chromogranins , DNA Mutational Analysis , Female , Fibroma, Ossifying/genetics , Humans , Male , Middle Aged , Osteosarcoma/genetics , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction , Sensitivity and Specificity , Young AdultABSTRACT
Thymidine phosphorylase (TP)/platelet-derived endothelial cell growth factor is associated with tumor angiogenesis. We evaluated the TP mRNA and protein expression in basal cell carcinomas (BCC) and in various skin tumors including numerous BCC histological simulants. Immunohistochemistry was performed on 99 paraffin sections of formalin-fixed skin tumors using monoclonal antibodies (mAb) against TP. TP mRNA levels were measured by real time RT-PCR in whole BCCs (wBCC) and laser capture microdissected (LCM) BCC tumor cells. TP immunostaining was negative in all BCC variants and in most of the benign trichogeneic tumors studied. By contrast, TP was constantly immunodetected in actinic keratosis (AK), squamous cell carcinomas (SCC), syringomatous carcinomas (SC), basosquamous carcinomas (BSC) and melanomas. TP mRNA levels were low and statistically not different in wBCC and normal skin but were strongly downregulated in LCM-BCC as compared with LCM-normal epidermis. We concluded that (i) anti-TP mAb is an useful marker to differentiate BCC from AK, SCC, BSC and SC but not from trichoblastic tumors, (ii) the lack of TP protein expression in BCC tumoral cells is linked to transcriptional regulatory mechanisms, (iii) the low TP mRNA levels in whole BCC may be related to the low intra-tumoral microvessel density, the slow growth and the very low metastatic potential of these tumors.
Subject(s)
Carcinoma, Basal Cell/pathology , Skin Neoplasms/pathology , Thymidine Phosphorylase/genetics , Carcinoma, Basal Cell/genetics , Carcinoma, Basal Cell/metabolism , Carcinoma, Basosquamous/genetics , Carcinoma, Basosquamous/metabolism , Carcinoma, Basosquamous/pathology , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/metabolism , Carcinoma, Squamous Cell/pathology , Down-Regulation , Gene Expression Regulation, Neoplastic , Humans , Immunohistochemistry , Keratosis, Actinic/genetics , Keratosis, Actinic/metabolism , Keratosis, Actinic/pathology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Skin Neoplasms/genetics , Skin Neoplasms/metabolism , Thymidine Phosphorylase/biosynthesisABSTRACT
We report the case of a 54-year-old patient presenting with a typical pernicious anaemia. His mother was diagnosed with unquestionable pernicious anaemia 5 years previously. Serum ferritin was strongly increased (1,160 microg/l, normal range 29-380), with a transferrin saturation of 95%. We found a homozygous C282Y mutation of the HFE gene in our patient, his mother being heterozygous. The son of our patient was compound C282Y/H63D heterozygous without detectable pernicious anaemia. This seems to be the first report of an association between familial pernicious anaemia and hereditary haemochromatosis. The simultaneous occurrence of the 2 diseases in the same patient helps to delineate the relative contribution of each of them to iron metabolism and erythropoiesis: iron overload was only moderately increased and responded rapidly to phlebotomies, whereas haemochromatosis did not modify the cytologic presentation of pernicious anaemia.
Subject(s)
Anemia, Pernicious/complications , Hemochromatosis/complications , Adult , Anemia, Pernicious/drug therapy , Anemia, Pernicious/genetics , Hemochromatosis/genetics , Hemochromatosis Protein , Histocompatibility Antigens Class I/genetics , Humans , Male , Membrane Proteins/genetics , Middle Aged , Mutation , Vitamin B 12/administration & dosage , Vitamin B 12/blood , Vitamin B 12/therapeutic useABSTRACT
Our retrospective study analyzes various factors to evaluate the risk of invasion of the not sentinel node when the sentinel node biopsy is positive in the infiltrated breast cancers. We compared in single varied then multivaried analysis, various parameters between two groups: positive not sentinel nodes and negative not sentinel nodes among 180 cases of positive sentinel node biopsy between 2001 and 2004. At the time of the single varied analysis, seem to be risk factors of non sentinel node involvement: the histopronostic SBRIII rank, positive a HER2neu status, the presence of extracapsulal node extension and infiltration of the sentinel node by a macrometastasis. The tumoral embol, the absence of hormonal receivers, a tumoral size > 10 mm and the number of sentinel node taken appear at the limit of the significativity. In multivaried analysis, SBRIII rank and the presence of an extracapsular node extension remain related to non sentinel node involvement. The histological type, association with a CIS, the size of the sentinel nodes, the number of positive sentinel nodes and the year of surgery are nonsignificant. Additional axillairy clearing out at the time of a positive node sentinel biopsy should be discussed according to different criteria determined by a precise histological analysis.
Subject(s)
Breast Neoplasms/pathology , Breast Neoplasms/surgery , Lymph Node Excision , Sentinel Lymph Node Biopsy , Adult , Aged , Aged, 80 and over , Analysis of Variance , Axilla , Coloring Agents , Female , Humans , Lymphatic Metastasis , Middle Aged , Retrospective Studies , Rosaniline DyesABSTRACT
Methacarn and RCL2, a new noncrosslinking fixative, were compared to formalin-fixed or frozen tissue samples of the same invasive breast carcinoma and were evaluated for their effects on tissue morphology and immunohistochemistry as well as DNA and RNA integrity. The histomorphology of methacarn- or RCL2-fixed paraffin-embedded tumors was similar to that observed with the matched formalin-fixed tissues. Immunohistochemistry using various antibodies showed comparable results with either fixative, leading to accurate breast tumor diagnosis and determination of estrogen and progesterone receptors, and HER2 status. Methacarn and RCL2 fixation preserved DNA integrity as demonstrated by successful amplification and sequencing of large DNA amplicons. Similarly, high-quality RNA could be extracted from methacarn- or RCL2-fixed paraffin-embedded MCF-7 cells, whole breast tumor tissues, or microdissected breast tumor cells, as assessed by electropherogram profiles and real-time reverse transcriptase-polymerase chain reaction quantification of various genes. Moreover, tissue morphology and RNA integrity were preserved after 8 months of storage. Altogether, these results indicate that methacarn, as previously shown, and RCL2, a promising new fixative, have great potential for performing both morphological and molecular analyses on the same fixed tissue sample, even after laser-capture microdissection, and can open new doors for investigating small target lesions such as premalignant breast lesions.
Subject(s)
Breast Neoplasms/genetics , Breast Neoplasms/pathology , Fixatives , Nucleic Acids/genetics , Cell Line, Tumor , Chromosomes, Human/genetics , DNA/genetics , Humans , Immunohistochemistry , In Situ Hybridization , Paraffin Embedding , RNA/genetics , Receptor, ErbB-2/geneticsABSTRACT
Interferon has been shown to be an effective treatment of congenital dyserythropoiesis type I (CDA-I), but the optimal dose and the feasibility of this treatment remains to be determined. Here, in a 9-yr follow-up of a single patient, we show that interferon remains active during such a long period. The optimal dose of conventional alpha interferon could be evaluated at 2 million units twice a week. Pegylated interferon could be used as well at a dose of 30 microg/wk. During interferon treatment, serum and erythrocyte ferritin levels decreased progressively, and remained inversely correlated with haemoglobin levels. On repeated liver biopsies, iron overload could be normalized. Low dose interferon is a long-term treatment of CDA-I, and allows a significant decrease in iron overload, that could be interesting even in patients who are only moderately anaemic.
Subject(s)
Anemia, Dyserythropoietic, Congenital/drug therapy , Interferon-alpha/administration & dosage , Iron Overload/prevention & control , Adult , Biopsy , Erythrocytes/chemistry , Female , Ferritins/blood , Hemoglobins/analysis , Humans , Liver/chemistry , Time FactorsABSTRACT
We report a retrospective immunohistochemical study on bone marrow biopsies of 43 patients with different types of lymphomas showing unusual intrasinusoidal infiltration. Most of these patients presented with splenomegaly (74.4%) and peripheral lymphocytosis (83%). In 20/43 patients, lymphoid infiltrates were not detectable on haematoxylin-eosin sections. After immunohistochemistry on bone marrow biopsies and blood and bone marrow smear examinations, the following diagnoses were made: splenic marginal zone lymphoma with villous lymphocytes (SLVL) in 24 patients, large granular lymphocyte (LGL) leukaemia in 14 patients, hepatosplenic T-cell lymphoma in two patients, anaplastic large cell lymphoma in two patients and intravascular large B-cell lymphoma in one patient. In the presence of intrasinusoidal infiltrates of small lymphocytes, a B-cell phenotype (CD20+, CD76/DBA44+/-) was associated with splenic marginal zone lymphoma whereas intrasinusoidal CD3/CD45RA-positive T-cell infiltrates were strongly suggestive of LGL leukaemia. Intrasinusoidal bone marrow infiltration appears to be a common feature of distinct lymphoma subtypes. Immunohistochemical analysis is essential to detect intrasinusoidal medullary infiltrates (which may be minimal) and should be systematically performed in patients with splenomegaly and peripheral lymphocytosis.