Intravascular large cell lymphoma: clinicopathological, immuno-histochemical and molecular genetic studies

Reactive Intralymphovascular Immunoblastic Proliferations Mimicking Aggressive Lymphomas

Reactive intralymphovascular immunoblastic proliferations (ILVIPs) may mimic aggressive lymphomas and are rarely reported. Herein, we characterize the clinicopathologic features of 8 patients with ILVIPs. No patients had lymphadenopathy, hepatosplenomegaly, or other findings suggestive of lymphoma. The ILVIPs involved the small or large intestine (n=5) and appendix (n=3). Patients were evaluated for abdominal pain, suspected appendicitis, intestinal obstruction, diverticulitis, volvulus, or tumor resection. Histologic sections showed expanded lymphovascular spaces filled by intermediate to large immunoblasts, positive for CD38, CD43, CD45, CD79a, and MUM1/IRF4 in all cases tested. Five of 6 (83%) cases were positive for CD30. CD20 was weakly positive in a subset of cells in 2 (25%) cases, and PAX5 was weakly positive in 4 (50%) cases. The immunoblasts expressed polytypic light chains in all cases tested. In 1 case, a subset of immunoblasts expressed T-cell markers indicating the presence of a T-cell component. The immunoblasts were negative for ALK, BCL-2, BCL-6, CD10, CD56, CD138, and Epstein-Barr virus-encoded small RNA in all cases assessed. The proliferation index shown by Ki-67 was high with a median of 80%. In all 6 cases tested, the immunoblasts were shown within lymphatic channels highlighted by D2-40. In conclusion, ILVIPs can be rarely observed in patients with inflammatory or infectious conditions, especially in gastrointestinal tract surgical specimens. The immunoblasts are predominantly of B-lineage with a postgerminal center immunophenotype and are located within lymphatic channels. It is essential to distinguish reactive ILVIPs from aggressive lymphomas to avoid unnecessary therapy.

Intravascular Large B-cell Lymphoma: A Report of Two Cases

One of the rare variants of extranodal large B-cell lymphoma is intravascular large B-cell lymphoma (IVLBCL). Characteristics of IVLBCL include intraluminal selective proliferation of atypical lymphoid cells in small to medium-sized vessels. The etiologic of IVLBCL is unknown, but due to the growth pattern of this tumor, it is speculated that IVLBCL is caused by a defect in homing receptor of tumor cells. IVLBCL can involve any organ but central nervous system, lungs, and skin are the most involved sites. IVLBCL does not usually involve lymph nodes. IVLBCL mainly occurs in the middle aged to elderly population with a slight male predominance. Generally, IVLBCL is aggressive and rapidly fatal if left untreated.

We here reported two cases of IVLBCL who succumbed to the disease at initial phase of treatment to emphasize the difficulty in diagnosis of IVLBCL due to its exclusive intravascular growth pattern and fulminant clinical course.

Gastric Intravascular Lymphoma in a Dog: Case Report and Literature Review

Intravascular lymphoma (IVL) is a rare, high-grade, extranodal lymphoma characterized by selective proliferation of neoplastic lymphocytes within the lumen of small vessels. A 10 yr old female intact mixed-breed dog was presented with a 7 mo history of vomiting and anorexia. Physical examination revealed abdominal discomfort. Ultrasonography and endoscopy identified a submucosal gastric mass. Excision was performed by partial gastrectomy and histopathology and immunohistochemistry confirmed a T-cell IVL. The owner declined chemotherapy, and the dog was instead treated palliatively with prednisolone. Two months after surgery, vomiting recurred and abdominal ultrasonography revealed a large gastric ulcer with focal peritonitis. The dog was euthanized 4 mo after initial presentation and postmortem examination confirmed IVL recurrence in the stomach and an isolated nodule of neoplastic cells in the omentum. No involvement of other organs was found following histopathological examination. This is the first description of primary gastric intravascular lymphoma causing chronic vomiting in a dog.

A study of PD-L1 expression in intravascular large B cell lymphoma: correlation with clinical and pathological features

Intravascular large B cell lymphoma (IVLBCL) is a rare, aggressive, extranodal large B cell lymphoma characterised by growth of tumour cells within the lumen of vessels, particularly capillaries. Programmed cell death ligand 1 (PD-L1) is a cell surface glycoprotein that interacts with programmed death 1 (PD-1) on the T cell surface, leading to modulation of the immune response. PD-L1 is a targetable immune check-point molecule that is expressed on neoplastic cells in various cancers, including a subset of lymphomas. We correlated the expression of PD-L1 with clinical and pathological findings in this rare disease. Eleven cases of IVLBCL were identified in the archives of Laboratory of Pathology at the National Cancer Institute, NIH. A panel of immunostains (CD20, CD3, CD5, PD-L1) was performed. The cases were classified as the classic form or the variant associated with haemophagocytic syndrome (HPS) based on published 2017 WHO criteria. Three cases (27.3%) were HPS variant and eight cases (72.7%) were the classic form. Five (45.5%) of 11 cases were CD5-positive; two of three (66%) were HPS variants and three of eight (37.5%) were classic form. Overall, four of nine evaluable cases (44.4%) were positive for PD-L1, three of which were classic. Only one CD5-positive case was PD-L1-positive, a classic variant. In summary, a subset of IVLBCL express PD-L1. Although limited, these data suggest that PD-L1 is expressed in both the so-called classic form as well as the HPS variant. PD-L1 is expressed irrespective of CD5 expression. Finally, detection of PD-L1 expression in a subset of IVLBCL lymphoma cases may identify patients who might benefit from targeted immunotherapy.

Intravascular Lymphoma in the CNS: Options for Treatment

Purpose of review The purpose of this review was to discuss therapeutic manipulations and effective current interventions available to treat intravascular lymphoma in the central nervous system.

Recent findings Patients experienced resolution and remission of disease for 14 months and up to 2 years after eight cycles of R-CHOP and four courses of intrathecal therapy with MTX, cytarabine, and prednisolone. Intravascular use of unfractionated heparin during therapy may contribute to better outcome.

Summary Series of therapeutic avenues were analyzed and compared. The effective current treatment of intravascular lymphoma in the CNS is considered to be a combinational intrathecal methotrexate-based chemotherapy with rituximab. Since intrathecal administration bypasses the blood–brain barrier, lower doses can be given, which thereby minimizes systemic toxicity. Practical use of intrathecal chemotherapy is also justified for prophylaxis in intravascular lymphoma-diagnosed patients without CNS involvement.

Uncommon Causes of Cerebral Microbleeds

BACKGROUND

Cerebral microbleeds (CMBs) are small and round perivascular hemosiderin depositions detectable by gradient echo sequences or susceptibility-weighted imaging. Cerebral microbleeds are common among patients with hypertension, cerebral ischemia, or cerebral amyloid angiopathy. In this article, we describe uncommon causes of CMBs.

METHODS

We searched Pubmed with the keyword CMBs for relevant studies and looked for different uncommon causes of CMBs.

RESULTS

CMBs have several uncommon etiologies including posterior reversible encephalopathy syndrome, infective endocarditis, brain radiation therapy, cocaine abuse, thrombotic thrombocytopenic purpura, traumatic brain injury, intravascular lymphomatosis or proliferating angio-endotheliomatosis, moyamoya disease, sickle cell anemia/β-thalassemia, cerebral autosomal dominant arteriopathy subcortical infarcts, and leukoencephalopathy (CADASIL), genetic syndromes, or obstructive sleep apnea.

CONCLUSIONS

Understanding the uncommon causes of CMBs is not only helpful in diagnosis and prognosis of some of these rare diseases, but can also help in better understanding different pathophysiology involved in the development of CMBs.

Asian-variant intravascular large B-cell lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a rare and deadly malignancy involving the growth of lymphoma cells within vessel lumina of all organ types. IVLBCL is further divided into the hemophagocytic Asian variant and a classical Western variant. Both variants are difficult to diagnose by imaging, and although diagnostic criteria have been developed to guide workup, histopathological examination remains imperative. Treatment of IVLBCL remains difficult given the high mortality of the disease, but rituximab has emerged as a promising therapeutic option when combined with various cytotoxic regimens. The two main variants of IVLBCL generally manifest in their respective Asian or Western populations, and crossover between ethnicities is rare. We present the second described case of Asian-variant IVLBCL in an African American individual.

Retrospective study of intravascular large B-cell lymphoma cases diagnosed in Quebec: A retrospective study of 29 case reports

INTRODUCTION

Intravascular large B-cell lymphoma (IVL) is an extremely rare malignancy, mainly studied through European and Asian series. Due to the low incidence of this condition, our understanding of the clinical presentation as well as the management of IVL relies on a limited number of patients.We report the largest North American study to date on IVL with 29 cases from Quebec hospital diagnosed between 1990 and 2016. The aim of our study is to describe the clinical presentations, diagnostic and staging procedures, therapeutic management and clinical outcomes of IVL patients in our population and compare the disease phenotype to European and Asian series reported.In our cohort, all patients had stage IV IVL at diagnosis, with a median age of 66.7 years (range 47.2-90.8). Clinical presentation was characterized by constitutional symptoms (100%), poor ECOG-PS (100% ≥ 2), cytopenias (93% anemia), and elevated lactate dehydrogenase (97%) and C-reactive protein (96%). Our cohort presented with mainly cutaneous and neurological symptoms. However, neurological involvement (75.9%) was predominant and no "cutaneous variant" was observed; this differs from European literature, where "classical" IVL is reported with mainly cutaneous involvement. Two of our Caucasian patients presented "Asian variant" IVL; this observation is not unusual, as cases of "classical" IVL have been reported in Asians and "Asian variant" IVL has been reported in Europeans. All patients were classified according to their immunophenotypic features in 3 different subgroups (CD5 or CD5CD10, CD5CD10, CD5CD10) with no difference in outcome. Finally, 62% of our cohort received anthracycline-based chemotherapy and 53% of them achieved a complete response. After a median follow-up of 328 days, OS at 3 years was 42.7% for the entire cohort and 47.4% for the cases with in vivo diagnosis.

CONCLUSION

Unlike European studies on "classical" IVL, our study showed that the French Canadian presentation of this subtype of IVL is more frequently observed with neurological rather than cutaneous involvement. Finally, an early diagnosis is of primary importance since almost a quarter of patients receive a post-mortem diagnosis. A prompt diagnosis allows the introduction of an early treatment, associated with a CR in 53% of patients.

[Macrophage activation syndrome as the presenting manifestation of intravascular lymphoma]

INTRODUCTION

Intravascular large B cell lymphoma is a neoplastic cell proliferation leading to the occlusion of the lumen of small vessels. This is a rare haematological malignancy, which is difficult to diagnose because of a heterogeneous clinical presentation.

CASE REPORT

We report a 62-year-old man who presented a macrophage activation syndrome as the presenting manifestation of an intravascular lymphoma. This association is frequently marked by a greater severity and clinical care requires an early and appropriate treatment.

CONCLUSION

Due to the polymorphism and the systemic presentation of intravascular large B cell lymphoma, the internist may be confronted with this disease, which is considered to be more severe if associated with a macrophage activation syndrome. Awareness of the intravascular large B cell lymphoma is important because the prognosis depends on the rapidity of the initiation of chemotherapy associated with rituximab.

Intravascular CNS lymphoma: Successful therapy using high-dose methotrexate-based polychemotherapy

Intravascular diffuse large B-cell lymphoma limited to the CNS (cIVL) is a very rare malignant disorder characterized by a selective accumulation of neoplastic lymphocytes (usually B cells) within the lumen of CNS blood vessels but not in the brain parenchyma. In the past, treatment of cIVL with anthracycline-based regimens was unsatisfactory with very short survival times. In the case of cIVL presented here, high-dose methotrexate-based polychemotherapy according to the Bonn protocol plus rituximab therapy was successful and led to a complete clinical and MRI remission which is ongoing 29 months after diagnosis.

Intravascular large B-cell lymphoma

A rare type of diffuse large B-cell lymphoma, intravascular large B-cell lymphoma primarily affects the middle-aged to elderly population, with a slight predominance in men. By the time of presentation, most patients have advanced, disseminated disease, and often the diagnosis is made at autopsy. Patients may present with any of a myriad of symptoms, with any tissue potentially being infiltrated. Central nervous system and cutaneous involvement is common, as is the presence of B symptoms including fever, weight loss, and night sweats. Morphologically, growth of neoplastic cells is restricted to the lumen of small vessels. The cells are large, with 1 or more prominent nucleoli, scant cytoplasm, and frequent mitotic figures, and are commonly positive for cluster of differentiation markers 79a, 20, and 19, as well as MUM1/IRF4 and Bcl-2. Intravascular large B-cell lymphoma is aggressive, and without treatment is rapidly fatal.

Intravascular large B cell lymphoma in Taiwan: an Asian variant of non-germinal-center origin

BACKGROUND/PURPOSE

Intravascular large B cell lymphoma (IVLBCL) is a rare variant of diffuse large B cell lymphoma. We reported the clinical and immunohistochemical characteristics of 10 cases of IVLBCL from Taiwan between 1995 and 2008.

METHODS

Clinical data were reviewed and immunoperoxidase stains were performed with antibodies against CD20, CD10, Bcl-6, MUM1, and CD5.

RESULTS

There were eight males and two females with a median age of 59 years. Patients presented with dyspnea (5/10), fever (7/10), splenomegaly (5/10), and bone marrow involvement (8/10). Anemia (9/10), thrombocytopenia (6/10), and elevated serum lactate dehydrogenase or ferritin levels (8/10) were also common. Nine cases were CD20+CD10(-)Bcl-6(-), similar to non-germinal center B cells. Six out of seven patients survived after chemotherapy, but three cases with thrombocytopenia that precluded chemotherapy died within 2 months.

CONCLUSION

Our cases of IVLBCL had a non-germinal center B origin and belonged to the Asian variant of this disease. The liver, spleen, and bone marrow, but rarely the skin or brain, were involved. Thrombocytopenia is a major risk factor for mortality in these cases.

Intravascular lymphomatosis and intracerebral haemorrhage

Intravascular lymphomatosis (IVL) is a rare, malignant B- or T-cell lymphoma with remarkable affinity for the endothelial cells of small vessels, particularly within the skin and central nervous system. It is a disease that mimics several neurological disorders, particularly those of cerebrovascular ischemic origin. The prognosis is generally poor, with a rapidly fatal outcome. As a result the diagnosis is often made at post-mortem. We report a rare case of a 73-year-old patient with IVL complicated by intracerebral haemorrhage. In literature two cases of systemic IVL complicated by intracerebral haemorrhage have been reported, but they presented initially with a disseminated intravascular coagulation (DIC). This is the first case of brain IVL complicated by intracerebral haemorrhage not associated to DIC. Increasing awareness of this disease as a differential diagnosis to a common clinical presentation may lead to more opportunities to evaluate new diagnostic and treatment approaches.

The therapeutic effect of rituximab on CD5-positive and CD5-negative diffuse large B-cell lymphoma

The prognosis of diffuse large B-cell lymphoma (DLBCL) has improved markedly in recent years of rituximab era. The prognosis of de novo CD5-positive DLBCL is reported to be poor, but the effect of rituximab on this type of lymphoma remains unclear. To investigate the effect of rituximab on CD5-positive DLBCL, we collected DLBCL patients and analysed prognostic factors. A total of 157 patients with DLBCL who were immunophenotyped with flow-cytometry (FCM) and treated with chemotherapy were subjected to analysis. Those treated with radiotherapy alone or with supportive therapy only were not included. Patients diagnosed in 2003 or later were treated with rituximab combined chemotherapy. There were 95 males and 62 females. Their age ranged from 20 to 91 years old, and the median was 65 years. Nineteen patients were diagnosed as having de novo CD5-positive DLBCL. Rituximab was given alongside chemotherapy in 85 patients. Of these, 11 were positive for CD5 and 74 were negative. The addition of rituximab improved the overall survival (OS) of DLBCL patients (2-year OS: 82% vs. 70%, p = 0.01). For CD5-negative DLBCL, patients treated with rituximab showed 2-year OS of 84%, which was significantly better than those treated without rituximab (70%, p = 0.008). However, for CD5-positive DLBCL, the prognosis was not statistically different between the patients treated with and without rituximab (59% vs. 50%, p = 0.72). Although rituximab improved the prognosis of DLBCL, such improvement was restricted to the CD5-negative group. Further investigation is required to improve the prognosis of patients with CD5-positive DLBCL.

Intravascular lymphoma presenting as an orbital mass lesion: a case report

We describe a case of intravascular lymphoma that presented as an orbital mass lesion. A 77-year-old female presented with longstanding fatigue and one-month of diplopia. Magnetic resonance imaging (MRI) revealed a frontal lobe brain lesion and a right orbital mass. Brain biopsy was interpreted as anaplastic oligodendroglioma. Orbital biopsy revealed intravascular lymphoma. On review of brain histopathology, the diagnosis was revised to CNS intravascular lymphoma. To the best of our knowledge, this case represents the first report of intravascular lymphoma presenting as an orbital mass lesion.

Presentation and management of intravascular large B-cell lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a rare disease entity of non-Hodgkin lymphoma according to the current WHO classification. This rare form of B-cell lymphoma is characterised by selective growth of tumour cells in the lumina of small vessels of various organs. Strange characteristics of IVLBCL, including the absence of marked lymphoadenopathy and the usually aggressive clinical behaviour, result in the delay of timely and accurate diagnosis and fatal complications. Thus, the prognosis of IVLBCL is extremely poor. The success achieved with the anti-CD20 chimeric monoclonal antibody, rituximab, represents an important milestone in the clinical practice of B-cell lymphoma. An advantage of adding rituximab to conventional chemotherapies has been shown, in the process of increasing our understanding of the clinical and pathological manifestations for IVLBCL. This Review describes the cutting edge of research on IVLBCL, and discusses the unsolved issues from biological and clinical perspectives to provide a better understanding of this rare lymphoma.

Usefulness of Bone Marrow Aspiration for Definite Diagnosis of Asian Variant of Intravascular Lymphoma: Four Autopsied Cases

The Asian variant of intravascular lymphoma (AIVL) is characterized by hemophagocytic syndrome, pancytopenia and hepatosplenomegaly but usually lacks any neurological abnormality and skin lesions, which are typical features of classical intravascular lymphoma (IVL). An ante-mortem diagnosis of AIVL is difficult due to the absence of visible lymphoma lesions and unspecific clinical manifestations. A definite diagnosis relies on the presence of neoplastic B cells in the lumina of small vessels. Paraffin block samples of aspirated bone marrow clots were obtained from 4 patients with clinically suspected IVL and subjected to immunohistopathological analysis. All samples exhibited CD 20+ or CD 79a+ lymphoma cells proliferating intravascularly as well as erythrocytic hemophagocytosis. The distribution of neoplastic cells in the structure of the bone marrow allowed IVL to be distinguished from bone marrow invasions due to other types of lymphoma. We demonstrated the successful establishment of a definite ante-mortem diagnosis of AIVL in 3 of 4 patients by the rapid and simple method of using aspirated bone marrow samples.

Diffuse Large B-Cell Lymphoma—More Than a Diffuse Collection of Large B Cells: An Entity in Search of a Meaningful Classification

Context.—Diffuse large B-cell lymphoma is a heterogenous group of lymphomas. In this review, we present a brief description of the large number of entities recognized in the recently published (2008) World Health Organization classification of tumors of hematopoietic and lymphoid tissues.

Objective.—We highlight the unique clinicopathologic and molecular genetic features of these new and previously recognized entities, to illustrate the rational for the development of this classification. To help simplify the understanding of this now large and complex group of diseases, we have attempted to create broader subgroups of related entities. We discuss large B-cell lymphoma that are not otherwise specified, those that are based on anatomic site, those that have unique histology or phenotype or genotype, those that are associated with Epstein-Barr virus or Kaposi sarcoma–associated herpesvirus and herpesvirus 8, and those that are unclassifiable.

Data Sources.—World Health Organization classification of tumors of hematopoietic and lymphoid tissues (2008), published literature from PubMed (National Library of Medicine), and primary material from the authors' institution were reviewed.

Conclusions.—Recognition of the different subtypes of diffuse large B-cell lymphoma as described in the World Health Organization classification scheme will lead to improved understanding of the unique clinicopathologic and genetic features associated with these subtypes of lymphoma.

Intravascular large B cell lymphoma: proposed of the strategy for early diagnosis and treatment of patients with rapid deteriorating condition

We summarize our experience and propose methods for early diagnosis and treatment of intravascular large B cell lymphoma (IVL). A total of 16 patients with IVL between 1994 and 2007 were included and analyzed in this study. Predicted survival durations were short until September 2003. However, there have been marked improvement since the introduction of rituximab, and all patients responded to treatment and survived for more than 1 year following diagnosis of IVL. We propose an early clinical diagnostic strategy for starting treatment for IVL patients with quite poor performance status (PS) and in whom time is a limiting factor: (1) age >40 years, (2) fever above 38 degrees C with poor PS (ECOG 2-4), (3) lactate dehydrogenase (LDH) more than twice the upper limit of the normal level and/or sIL2R >5,000 IU/ml in serum, (4) worsening PS and/or elevation of serum LDH on a daily basis, and (5) confirmation of pathological lymphoid cells in peripheral blood or bone marrow smear and/or flow cytometry. Although accurate pathological diagnosis is quite important, time is a limiting factor for most of IVL patients. In such cases, we can start chemotherapy based on early clinical diagnostic strategy with high sensitivity and obtain good clinical outcome.

Intravascular cytotoxic T-cell lymphoma: A case report and review of the literature

Intravascular lymphoma (IVL) is a rare subtype of extranodal diffuse large B-cell lymphoma in the World Health Organization classification. Although the majority of cases are of B-cell lineage, cases of IVL with a T-cell phenotype and, rarely, histiocytic and natural killer (NK)-cell phenotypes have been reported. We report a case of T-cell IVL with a cytotoxic phenotype. A 62-year-old male presented with erythematous patches and plaques on the lower extremities, and a biopsy revealed IVL with an activated cytotoxic phenotype (CD56(+), perforin+, granzyme B+, TIA-1+, CD3epsilon(+), CD20(-), CD4(-), CD8(-), CD5(-), and T-cell receptor [TCR] betaF1(-)), consistent with either NK-cell or T-cell origin. TCR gene analysis showed a monoclonal T-cell population, supporting the diagnosis of a T-cell IVL. Although the patient's skin lesions were refractory to combination chemotherapy and salvage chemotherapy regimens, there has been no evidence of disease progression in 24 months of follow-up.

Skin manifestations of intravascular lymphoma mimic inflammatory diseases of the skin

BACKGROUND

Intravascular lymphoma (IVL) is fatal when it is diagnosed late in the course. Sometimes skin lesions enable early diagnosis, but criteria for diagnosis are not well established.

OBJECTIVES

To demonstrate the clinical spectrum of skin lesions of IVL and to correlate it with clinical outcome; to identify features differentiating between B-cell and T-cell IVL with skin involvement.

METHODS

Review of 97 articles reporting on total of 224 patients with IVL.

RESULTS

Skin lesions were mentioned in 90 of 224 patients. They were nodules and/or plaques (49%) or macules (22.5%) of red (31%) or blue to livid (19%) colour on the leg (35%), the thigh (41%) and the trunk (31%). Telangiectases were present in only 20% of the patients. Oedema (27.5%) of the legs and pain (24%) were often accompanying. No criteria enabled distinction between lesions restricted to the skin and skin lesions concurrent with IVL in other organs, but when the disease was restricted to the skin, the prognosis was favourable (10% vs. 85% fatal outcome). Skin lesions of T-cell IVL are indistinguishable from those of B-cell IVL.

CONCLUSIONS

Forty per cent of all patients with IVL have skin lesions, these being red, sometimes painful plaques located typically on the lower extremities, accompanied by oedema. A clinician risks misinterpreting these changes as thrombophlebitis, erythema nodosum or erysipelas. Neither clinical course nor differentiation of the lymphoma can be predicted from the morphology of skin lesions, but involvement of other organs at the time of diagnosis indicates a poor prognosis.

Intravascular lymphoma: the oncologist's "great imitator"

Intravascular lymphoma (IVL) is a rare subtype of extranodal diffuse large B-cell lymphoma with a distinct presentation. Anatomically the disease is characterized by the proliferation of clonal lymphocytes within small vessels with relative sparing of the surrounding tissue. The clinical symptoms of the disease are dependent on the specific organ involvement, which most often includes the central nervous system and skin. Because of the various modes of presentation and the rarity of IVL, the diagnosis is often made postmortem. The diagnosis is almost exclusively made by surgical biopsy of a suspected site of involvement. Advances in imaging and immunohistochemistry have led to increasing antemortem diagnosis of this lymphoma. Although some patients with this disease may be curable with aggressive therapy, further research into novel treatment strategies is needed to improve outcome. Some potential insights into future therapies may be drawn from the small amount of basic science literature relevant to this entity. This review provides a concise, up-to-date summary of IVL.

Intravascular large B-cell lymphoma (IVLBCL): a clinicopathologic study of 96 cases with special reference to the immunophenotypic heterogeneity of CD5

Intravascular large B-cell lymphoma (IVLBCL) is pathologically distinct with a broad clinical spectrum and immunophenotypic heterogeneity. A series of 96 patients with IVLBCL (median age, 67 years; range, 41-85 years; 50 men) was reviewed. Anemia/thrombocytopenia (84%), hepatosplenomegaly (77%), B symptoms (76%), bone marrow involvement (75%), and hemophagocytosis (61%) were frequently observed. The International Prognostic Index score was high or high-intermediate in 92%. For 62 patients receiving anthracycline-based chemotherapies, median survival was 13 months. CD5, CD10, Bcl-6, MUM1, and Bcl-2 were positive in 38%, 13%, 26%, 95%, and 91% of tumors, respectively. All 59 CD10- IVLBCL cases examined were nongerminal center B-cell type because they lacked the Bcl-6+MUM1- immunophenotype. CD5 positivity was associated with a higher prevalence of marrow/blood involvement and thrombocytopenia and a lower frequency of neurologic abnormalities among patients with CD10-IVLBCL. Compared with 97 cases of de novo CD5+CD10-diffuse LBCL, 31 cases of CD5+CD10-IVLBCL exhibited higher frequencies of poor prognostic parameters, except age. Multivariate analysis in IVLBCL revealed that a lack of anthracycline-based chemotherapies (P<.001, hazard ratio [HR]: 9.256), age older than 60 years (P=.012, HR: 2.459), and thrombocytopenia less than 100x10(9)/L (P=.012, HR: 2.427) were independently unfavorable prognostic factors; CD5 positivity was not. Beyond immunophenotypic diversity, IVLBCL constitutes a unique group with aggressive behavior.

Primary extranodal nasal-type natural killer/T-cell lymphoma of the brain: a case report

Natural killer (NK)/T-cell lymphomas represent a rare type of lymphoma derived from either activated NK cells or, rarely, cytotoxic T cells. These lesions are most commonly extranodal and tend to present as destructive lesions within the midline facial structures. Other than the nasal cavity and paranasal sinuses, several other extranodal sites of involvement have been reported, including the pharynx, gastrointestinal tract, and testis. Although secondary involvement of the central nervous system has been reported, a convincing case of primary brain NK/T-cell lymphoma has not been previously reported. Here, we report a case of primary brain lymphoma of NK/T-cell type with a characteristic phenotype expressing CD3epsilon, CD56, granzyme B, Epstein-Barr virus-encoded small nuclear RNAs, with germline T-cell receptor gene configuration, and showing an unusual intravascular component. The patient underwent extensive imaging studies, revealing only the brain lesion. The lymphoma failed to respond to therapy and the patient eventually died after transfer to a hospice facility. This unusual case highlights an unusual presentation of a rare disease entity and highlights the need for a better understanding of the biology and treatment of T-cell lymphomas.

WHO/EORTC classification of cutaneous lymphomas 2005: histological and molecular aspects

The new WHO/EORTC classification for cutaneous lymphomas comprises mature T-cell and natural killer (NK)-cell neoplasms, mature B-cell neoplasms, and immature hematopoietic malignancies. It reflects the unique features of lymphoproliferative diseases of the skin, and at the same time it is as compatible as possible with the concepts underlying the WHO classification for nodal lymphomas and the EORTC classification of cutaneous lymphomas. This article reviews the histological, phenotypical, and molecular genetic features of the various nosological entities included in this new classification. These findings always have to be interpreted in the context of the clinical features and biologic behavior.

AIM

To review the histological, phenotypical and molecular genetic features of the various nosological entities of the new WHO/EORTC classification for cutaneous lymphomas.

METHODS

Extensive review of the literature cited in Medline and own data of the authors.

RESULTS

The WHO/EORTC classification of cutaneous lymphomas comprises mature T-cell and NK-cell neoplasms, mature B-cell neoplasms and immature hematopoietic malignancies. It reflects the unique features of primary cutaneous lymphoproliferative diseases.

CONCLUSION

This classification is as much as possible compatible with the concept of the WHO classification for nodal lymphomas and the EORTC classification of cutaneous lymphomas. The histological, phenotypical and molecular genetic features always have to be interpreted in the context of the clinical features and biologic behavior.

Fulminant intravascular lymphoma presenting as fever of unknown origin

Intravascular large cell lymphoma (IVLL) is a rare neoplasm characterized by the proliferation of malignant lymphoid cells within the lumens of small to medium-sized blood vessels. The central nervous system, skin, and endocrine systems are most commonly involved. IVLL may disseminate to the heart, pancreas, liver, spleen, kidneys, and adrenal glands. We report a 52-year-old patient who was admitted for fever of unknown origin for 3 weeks, jaundice and abnormal liver function tests. Fever, high levels of bilirubin, severe anemia, thrombocytopenia, and a very fulminant course characterized the clinical picture. Although bone marrow involvement is quite rare, the diagnosis of IVLL in this patient was done by bone marrow biopsy. The patient was treated with CHOP protocol and received the first course but the aggressive disease led to the patient's death.

Intravascular malignant lymphomatosis diagnosed on a muscular biopsy: a case report

Intravascular malignant lymphomatosis (IML) is characterized by proliferation of malignant lymphoid B cells within the lumens of small vessels. Common symptoms include general weakness and central neurological and cutaneous signs. Only histopathological analysis can confirm the diagnosis. We report on a 69-year-old man hospitalized for general weakness, inflammatory syndrome, and hemophagocytic syndrome (HS). Our observation shows that histopathological signs may be observed on a muscular biopsy without clinical or biological signs of muscular involvement.

Testicular ischemia due to intravascular large B-cell lymphoma: a novel presentation in an immunosuppressed individual

A 56-year-old man presented with fever, disorientation, and testicular pain. He was receiving azathioprine immunosuppression for autoimmune hepatitis. Orchiectomy identified occlusion of spermatic cord vessels by intravascular large B-cell lymphoma (IVLBL) and ischemic changes in the testis. Tumor cells were positive for CD 10, CD 20, CD 30, and Epstein-Barr virus (EBV) latent membrane protein 1 (LMP-1) and early region RNA (EBER). He was treated with the cessation of azathioprine, chemotherapy, anti-CD 20 immunotherapy, and radiotherapy. Twenty months after diagnosis, he is alive with no evidence of lymphoma or hepatitis. This is the first report of IVLBL presenting with testicular ischemia. It highlights the importance of prompt diagnosis and intervention to achieve durable response. That this lymphoma arose in the setting of immunosuppressive therapy introduces additional complexity relating to pathogenesis, clinical behavior, and treatment.

Epstein-Barr virus-associated intravascular large T-cell lymphoma presenting as acute renal failure in a patient with acquired immune deficiency syndrome

Intravascular lymphoma (IVL) is a rare neoplasm, recently included as a specific entity in the World Health Organization classification of lymphoid tumors. Most cases are of B-cell lineage; however, rare cases of T-cell phenotype have been reported. We report a human immunodeficiency virus (HIV)-positive patient who died of acute renal failure in whom IVL was identified at autopsy, predominantly involving the renal interstitial vessels. Immunohistochemical stains revealed a T-cell phenotype, which was confirmed by T-cell receptor gamma gene rearrangement studies. The lymphoma cells showed nuclear Epstein-Barr virus (EBV)-encoded RNA transcripts by in situ hybridization, suggesting that EBV might be of etiologic importance in this tumor. The predominant involvement of kidney is unusual. With effective therapy, morbidity and mortality of HIV-1 infection has been substantially reduced, and survival times have been prolonged. However, the relative risk of secondary neoplasms, especially non-Hodgkin's lymphoma (NHL), has increased. Consequently, we conclude that unique types of NHL, such as this case of IVL, may be encountered more frequently in this patient population, and that NHL should be added to the list of differential diagnostic considerations in HIV-1-positive patients who develop acute renal failure.

Intravascular B-cell lymphoma: report of two cases with different clinical presentation but rapid central nervous system involvement

Intravascular lymphomatosis (IVL) is a rare large-cell lymphoproliferative disorder characterized by a widespread lymphoma proliferation within the lumen of medium and small vessels, frequently presenting with skin and/or central nervous system (CNS) manifestations. The tumor is of B-cell origin in most cases. Prognosis is poor with a reported median survival of 5-7 months. We describe here two cases of IVL. The first was that of a 55-year-old woman with a large B-cell lymphoma of the leg, successfully treated with conventional chemotherapy (CHT) followed by autologous peripheral stem cell transplantation. At 3 months from the autograft she relapsed with a picture of hemophagocytic syndrome (HPS) and CNS symptoms. She died before any specific treatment, and post-mortem examination revealed the intravascular proliferation of lymphoma B-cells in the brain and bone marrow. The second case was that of a 60-year-old male with CNS involvement at diagnosis. He responded poorly to CHOP-like CHT, and died 2 months after diagnosis and 6 months after onset of symptoms. Failure of CHT at least in some IVL patients may be related to a delay in the initiation of therapy due to non-specific neurological symptoms. Therefore, early diagnosis based upon aggressive attempts immediately followed by adequate therapy may prove beneficial to these patients. In the present report, we performed an extended medline-based review of the published series of patients with IVL.

Intravascular lymphoma presenting with bone marrow involvement and leukemic phase

We describe the case of a 62-year-old man with recent onset of constitutional symptoms and vague intellectual deficit. The blood showed pancytopenia with blastemia, and bone marrow confirmed an extensive "vacuolated blast-like cell" infiltrate. Initial diagnosis of, and treatment for Burkitt's leukemia/lymphoma was questioned when the "blasts" typed as CD5+ mature B-cells; however, it was revised to intravascular lymphoma (IVL) only after the sinusoidal pattern was confirmed by immunocytochemistry. Literature review indicated that blood and bone marrow involvement in IVL appears to be rare, but a systematic search for this involvement is often not carried out. CD5 expression has been increasingly reported in this disease. The actual frequency and the significance of this expression are still to be defined.

A new approach to the diagnosis and treatment of intravascular lymphoma

In intravascular lymphoma (IVL) tumor cells are initially restricted to vascular lumina. Neurological syndromes predominate and are caused by ischemia as well as tumor infiltration into the nervous system. Ante mortem diagnosis is challenging and frequently impossible. Chemotherapy is effective if started prior to ischemic damage. Over a three year period, we have diagnosed IVL in seven patients. Tissue diagnosis could be accomplished in only three cases. Forthose in whom tissue diagnosis failed we based our diagnosis on clinical presentation, typical magnetic resonance imaging findings, spinal fluid cytopathology, and molecular analyses. Six patients were treated with methotrexate chemotherapy alone or in combination with CHOP. Three patients are in complete remission 9-20 months after initial diagnosis. Another patient achieved a partial response. Two patients died due to progressive disease shortly after initiation of treatment. Grade III toxicity was observed in only 4 of 61 cycles. Based on a small retrospective series of patients, we conclude that methotrexate is a well tolerated and effective agent for the treatment of IVL.

Prevalence of intravascular large B-cell lymphoma with bone marrow involvement at initial presentation

We used immunohistochemical analysis to investigate 146 bone marrow (BM) clot specimens from patients with fever of unknown origin (FUO) (n = 124) or hemophagocytic syndrome (HPS) (n = 22). Intravascular lymphoma (IVL) primarily involving BM was detected in 12 (8.2%) of the 146 patients. Diagnosis was based on the presence of CD20+ and CD79a+ tumor cells confined within the lumina of sinuses and surrounded by CD34+ endothelial cells. Of the 12 IVL cases, 6 were CD5+; of these 6 CD5+ cases, 5 were positive for vimentin. The finding of a considerably high prevalence of IVL tumor cells in BM from patients with FUO or HPS suggests that immunohistochemical examination of BM may be helpful in the diagnosis of IVL in these patients. Vimentin coexpression in CD5+ IVL might be evidence of origin from a subset of prefollicular B-cells.

Diffuse large B-cell lymphoma: one or more entities? Present controversies and possible tools for its subclassification

Diffuse large B-cell lymphoma (DLBCL) is the commonest type of lymphoid tumour world-wide. This category was included both in the REAL and WHO Classification aiming to lump together all malignant lymphomas characterized by the large size of the neoplastic cells, B-cell derivation, aggressive clinical presentation, and the need for highly effective chemotherapy regimens. These tumours are detected as primary or secondary forms both at the nodal and extranodal levels, in immunocompetent hosts as well as in patients with different types of immunosuppression. They display a significant variability in terms of cell morphology and clinical findings, which justifies the identification of variants and subtypes. Among the latter, the primary mediastinal one does actually correspond to a distinct clinicopathological entity. Immunophenotypic, tissue microarray and molecular studies underline the extreme heterogeneity of DLBCLs and suggest a subclassification of the tumour, based on the identification of different pathogenic pathways, which might have much greater relevance than pure morphology for precise prognostic previsions and adoption of ad hoc therapies. The more recent acquisitions on the pathobiology of DLBCLs are reviewed in the light of the authors' experience, aiming to contribute to the existing debate on the topic.

Intravascular large B-cell lymphoma with a fulminant clinical course: a case report with definite diagnosis post mortem

A patient is described who presented with pancytopenia, splenomegaly and excessively elevated lactate dehydrogenase levels in concurrence with signs of extramedullary hematopoiesis. Although initially considered in the differential diagnostic spectrum, a highly aggressive lymphoma could not be identified before the patient died, 6 weeks after admission. Even an intensive diagnostic work-up including splenectomy and repeated bone marrow biopsies was inconclusive. Finally, the diagnosis of an intravascular large B-cell lymphoma, a highly aggressive clinical subtype of a diffuse large B-cell lymphoma, spreading within vascular structures of multiple organs was established by autopsy. Intravascular large B-cell lymphoma is often not diagnosed before death due to the exclusive intravascular growth pattern of the tumor cells and a fulminant clinical course. The heterogeneous clinical features of this lymphoma subtype are discussed.

Clinicopathological and immunophenotypical features of canine intravascular lymphoma (malignant angioendotheliomatosis)

Intravascular lymphoma (IVL) is a rare angiotropic large-cell lymphoma in which neoplastic lymphocytes proliferate within the lumina of blood vessels in the absence of a primary extravascular mass or leukaemia. A retrospective review of veterinary medical records identified 17 cases of canine IVL. Spinal cord ataxia (seven dogs), posterior paralysis (one dog), seizures (four dogs) and vestibular disease (three dogs) dominated the clinical presentation. Haemorrhage, ischaemia, and occasional foci of vascular proliferation were found in tissue sections from affected dogs. Vessels, predominantly veins, throughout the body were frequently filled with neoplastic lymphocytes. Splenic involvement occurred in only one of 10 cases examined and bone marrow involvement was absent in four cases examined. Formalin-fixed paraffin wax-embedded tissues from 15 cases were examined immunohistochemically with streptavidin-biotin-horseradish peroxidase and a catalysed signal amplification system. The neoplastic cells were classified in eight cases as T cells (CD3+/IgG-/CD79a-), in one case as B cells (CD3-/CD79a.dim/IgG+), and in the remaining six cases as non-T, non-B (CD3-/IgG-/CD79a-). The clinical and pathological features of canine IVL closely resembled those of the human disease. In striking contrast to human cases, which are most often B-cell lymphomas, the immunophenotypes of the canine IVLs in this series were heterogeneous. The canine IVLs were derived primarily from T cells and non-T, non-B lymphocytes, B cells being found in only a single instance.

Angiotropic lymphoma: an immunophenotypically and clinically heterogeneous lymphoma

Angiotropic lymphoma (AL) is an uncommon lymphoma often presenting with nonspecific clinical features and having a high mortality rate. Although not specifically recognized by the Revised European-American Classification of Lymphoid Neoplasms, it likely will appear as a subtype of diffuse large B-cell lymphoma in the upcoming WHO classification. Some authors may also consider it to be a subtype of cutaneous lymphomas. Recent studies have reported an immunophenotypic heterogeneity of AL, and in rare instances, an association with other NHL. To further characterize AL, we studied the immunophenotype by immunohistochemistry for CD5, CD10, CD20, bcl-2, and bcl-6 in 18 cases of B-cell AL identified at three medical centers in North America. Bcl-2 gene rearrangement status by polymerase chain reaction and Epstein Barr virus status by in situ hybridization also were evaluated. Eight men and 10 women were identified with AL (median age 71 years). Eleven patients were diagnosed in life and seven were diagnosed at autopsy. Neurologic symptoms were the most common presentation, seen in six patients. Skin was the most commonly biopsied site. All showed classic intravascular localization; in two cases, there was also a minor diffuse large cell lymphoma component observed in some organs. Most (89%) of the cases expressed bcl-2 protein; CD10, bcl-6 and CD5 were each expressed in 22% of cases. Based on CD5 and CD10 expression, three major groups were evident: CD5-, CD10- (11 cases); CD5+, CD10- (3 cases), and CD5-, CD10+ (3 cases). Even though a follicle center lymphoma preceded the AL in one patient, we did not detect bcl-2 gene rearrangement in any of these cases. All cases were negative for Epstein Barr virus. Of the five treated with chemotherapy, two achieved a complete remission. Based on these findings, we conclude that ALs are clinically and immunophenotypically heterogeneous and may represent more than one pathogenetic entity. In some instances AL may be preceded by another lymphoproliferative disorder, raising the possibility that some cases of AL may represent a transformation from another type of lymphoma. Cutaneous manifestations of AL are common; however, it appears to be a systemic lymphoma. Although often fatal, patients with AL who are diagnosed early and treated with chemotherapy may achieve remission.

Hepatic failure as the presenting manifestation of malignant lymphoma

Fulminant hepatic failure carries a high mortality regardless of etiology. Liver transplantation may be lifesaving. Hepatic invasion by malignant lymphoma is a rare cause of liver failure, but one that is potentially responsive to treatment. Lymphoma (non-Hodgkin's or Hodgkin's) should be included in the differential diagnosis of fulminant hepatic failure so that liver transplantation is avoided and appropriate therapy can be instituted. The findings and clinical course of 4 patients with liver failure due to hepatic lymphoma, who were referred to our institution for liver transplant evaluation, are presented and discussed. Medical records, imaging studies, and histological material were examined. Review of the literature revealed less than 40 cases of lymphoma presenting as fulminant hepatic failure. The diagnosis of malignant lymphoma may be difficult. The presenting symptoms and signs are indistinguishable from other causes of fulminant hepatic failure. Early liver biopsy with adequate tissue and immunologic studies is mandatory for diagnosis. This condition may be reversible and may respond to chemotherapy if the diagnosis is made prior to multiorgan system failure. The presence of malignant lymphoma is considered a contraindication to liver transplantation, although firm data are lacking.

Hepatosplenic gamma/delta T-cell lymphoma in bone marrow. A sinusoidal neoplasm with blastic cytologic features

We report 8 cases of hepatosplenic T-cell lymphoma (HSTCL) involving bone marrow and correlate histologic findings with disease progression. Immunophenotypic analysis demonstrated mature, aberrant gamma/delta T-cell immunophenotypes. Isochromosome 7q was identified in 4 cases; 1 case showed the t(7;14)(q34;q13). Seven of 7 cases tested had monoclonal TCR gamma gene rearrangements. The initial diagnostic bone marrow biopsy specimens were hypercellular with a frequently subtle, predominantly sinusoidal infiltrate of atypical small to medium-sized lymphoid cells. In all cases, aspirate smears at diagnosis and in subsequent specimens contained malignant cells that resembled blasts, some with fine cytoplasmic granules. With progression, the pattern of HSTCL in bone marrow biopsy specimens became increasingly interstitial, and the neoplastic cells became larger. In aspirate smears, the proportion of blasts increased. Seven patients died; 1 was lost to follow-up. Autopsy performed on 1 patient demonstrated malignant cells within vascular channels in all organs sampled, with relatively little tumor formation, resembling intravascular lymphoma at these sites. HSTCL often can be recognized in bone marrow by its unique combination of a sinusoidal pattern in core biopsy specimens and blastic cytology in aspirate smears.

Changes in pattern of immunoglobulin heavy chain gene rearrangement and MIB-1 staining before and after eradication of Helicobacter pylori in gastric mucosa-associated lymphoid tissue (MALT) lymphoma

Gastric low-grade mucosa-associated lymphoid tissue (MALT) lymphomas are strongly associated with infection by Helicobacter pylori (H. pylori). Antibiotic treatment for H. pylori induces a sustained remission in a significant number of patients. We report here the outcome in 13 patients with gastric low-grade MALT lymphomas or suspected gastric lesions, treated for eradication of H. pylori. Patients were followed closely with sequential histological studies, polymerase chain reaction (PCR) amplification of the immunoglobulin heavy chain (IgH) gene and immunohistochemistry for MIB-1. Antibiotic therapy resulted in eradication of H. pylori in all but one case, as assessed histologically. In 12 cases with successful eradication, complete regression was observed histologically in 9 cases (75%) and no regression in 3 (25%). In 7 of 9 (78%) patients who had a complete remission, clonal bands of IgH gene detected on PCR before therapy disappeared after therapy. All 9 patients with complete regression showed a reduced number of MIB-1 positive cells, while 4 cases with no change or disease progression showed no change or increased number of MIB-1 positive cells. There was a strong relationship between density of MIB-1-positive cells and histological score. These results indicate that combination analysis of PCR of IgH and MIB-1 seems to represent a very good current approach for the diagnosis of gastric low-grade MALT lymphoma and to assess the effects of chemotherapy, especially in problematic cases.

Splenic lymphoproliferative disorders in human T lymphotropic virus type-I endemic area of japan: clinicopathological, immunohistochemical and genetic analysis of 27 cases

Primary splenic involvement in lymphoid neoplasms is rare and the clinicopathologic features of splenic lymphoma are not well described compared to nodal non-Hodgkin's lymphoma (NHL). Here we characterized splenic lymphomas in an human T lymphotropic virus type-I (HTLV-I) endemic area of Japan. To assess the pattern of splenic involvement and evaluate prognosis, we reviewed 27 specimens consisting of 26 splenectomies and one necropsy, which were classified using REAL classification. Cases were divided into primary splenic lymphoma in 11 patients and secondary in 16 patients. The incidence of primary splenic lymphoma was 0.3% (11 of approximately 4,000 malignant lymphomas). Primary splenic lymphomas included 7 diffuse large B cell lymphoma (DLBL), 2 follicular lymphomas (FL), and 1 each of splenic marginal zone lymphoma (SMZL) and anaplastic large cell lymphoma (ALCL). Secondary splenic lymphomas included 6 DLBL, 4 mantle cell lymphoma (MCL), 2 FL, 2 Hodgkin's disease (HD), 1 each of hairy cell leukemia and ALCL. Gross examination showed two patterns of splenic involvement; solid type (formation of large nodular mass, n=16) and disseminated type (multiple nodules with diffuse infiltration but no large nodular formation, n=10). The type could not be determined in one case. Most solid types were DLBL or FL, while MCL was of the disseminated type. Immunohistochemistry showed all but each 2 cases of ALCL and HD were of B lineage. Follow-up of 26 patients indicated that all but one patient with primary lymphoma were still alive (range, 1-89 months) and 8 of 15 patients with secondary lymphomas died due to the progression of malignant lymphoma; the survival rate at 2 years was 50% in these patients. No elevation of anti-HTLV-I antibody was found. In situ hybridization for Epstein-Barr virus (EBV) showed no reactivity of lymphoma cells, although a few small lymphocytes were positive for EBV. Hepatitis C virus was observed in 6 of 20 (30%) patients examined and 4 of 11 (36%) cases of primary splenic lymphoma. Our findings indicate that patients with primary splenic lymphoma have a favorable prognosis after splenectomy.

An Asian variant of intravascular large B-cell lymphoma: clinical, pathological and cytogenetic approaches to diffuse large B-cell lymphoma associated with haemophagocytic syndrome

Diffuse large B-cell lymphoma with haemophagocytic syndrome (BCL-HS) has been reported mainly in Asia and is regarded as a distinct variant of intravascular lymphoma (IVL). However, it is unclear whether all cases of BCL-HS fall within the framework of IVL and available clinical information is limited. We analysed 25 cases with BCL-HS, including 11 autopsied cases (median, 66 years; male-female ratio, 1.1:1). The patients presented with fever, anaemia, thrombocytopenia, hepatosplenomegaly, haemophagocytosis, bone marrow invasion, respiratory disturbance and disseminated intravascular coagulopathy, but usually lacked lymphadenopathy, mass formation, neurological abnormalities and skin lesions. The clinical course was aggressive with a median survival of 7 months. The morphological findings were uniform: large lymphoid cells infiltrated vessels and/or sinusoids of the liver, marrow, lung, kidney and other organs. They were positive for CD19, CD20, CD79a and HLA-DR, but negative for CD10, CD23 and CD30. CD5 was positive in five out of 17 cases. Our critical review indicates that BCL-HS is the equivalent of the Asian variant of IVL.