Primary brain CD30+ ALK1+ anaplastic large cell lymphoma ('ALKoma'): the first case with a combination of 'not common' variants

Primary CNS ALK-negative anaplastic large cell lymphoma: A case report and review of the literature

Primary central nervous system (CNS) ALK-negative anaplastic large cell lymphoma (ALCL) is a rare and enigmatic disease, with limited data available in the literature. This case report adds to the existing body of knowledge by describing a unique case of a 68-year-old, immunocompetent male who presented with a single ring-enhancing lesion, which upon further analysis proved to be an ALK-negative ALCL that was primary to the CNS. A comprehensive review of the existing literature is provided, highlighting the genetic characteristics and diverse neuroimaging findings of this disease entity. This report adds valuable information to the understanding of this rare disorder, and highlights the need for further research in the field of primary CNS ALK-negative ALCL.

Primary Anaplastic-Lymphoma-Kinase-Positive Large-Cell Lymphoma of the Central Nervous System: Comprehensive Review of the Literature

BACKGROUND

Primary anaplastic-lymphoma-kinase (ALK)-positive large-cell lymphoma of the central nervous system (PCNS ALK-positive ALCL) is a rare entity, with a limited consensus reached regarding its management. While this pathology often presents as solitary lesions, the occurrence of multiple tumors within the brain is not uncommon. The lack of distinctive radiological features poses a diagnostic challenge, leading to delays in initiating targeted therapy.

METHODS

We conducted a comprehensive literature search, identifying seventeen publications for qualitative analysis.

RESULTS

The management options and reported patient outcomes in the literature varied significantly, emphasizing the need for a patient-specific approach. The emergence of ALK-specific inhibitors represents a new frontier in this field, demonstrating promising results.

CONCLUSION

PCNS ALK-positive ALCL necessitates a comprehensive understanding and optimized management strategies. A tailored therapeutic approach, integrating surgical intervention with radiotherapy and chemotherapy, appears pivotal in addressing this pathology. The implementation of a therapeutic protocol is anticipated for further advancement in this field.

ALK-negative CNS anaplastic large cell lymphoma: case report and review of literature

BACKGROUND

Central nervous system (CNS) lymphomas frequently pose a diagnostic challenge to physicians. CNS anaplastic large cell lymphoma (ALCL) is a rare condition. A majority (80%) of ALCLs harbour anaplastic lymphoma kinase 1 (ALK-1) mutation with only a minority testing negative for this mutation.

METHODS

Here we report a rare case of ALK-negative CNS ALCL with dural involvement. We conducted a literature search using PubMed for published studies in English on cases of patients with ALCL of the brain. The keywords used were 'anaplastic large cell lymphoma', 'ALK' and 'primary central nervous system lymphoma'.

RESULTS

A 63-year-old man presents with waxing and waning cranial nerve and spinal cord symptoms. MRI revealed multiple intracranial and intra-spinal lesions that were highly steroid responsive. A wide range of serum and CSF tests were non-diagnostic during three months of workup before a lesion appeared in the cervical spine that required decompression and allowed us to obtain a tissue sample. Final pathology revealed ALK-negative ALCL. There are only 24 reported adult cases to date of CNS ALCL in the English literature. To our knowledge, this is the first case of ALK-negative ALCL with primarily CNS and meningeal involvement.

CONCLUSIONS

ALK-negative ALCL with CNS involvement is extremely rare, which frequently results in delayed diagnosis (average 40.5 days). The diagnostic challenge posed by this case highlights the importance of a team approach to workup and diligent patient follow-up for such a rare disease.

Primary Central Nervous System Anaplastic Large Cell Lymphoma, ALK Positive

OBJECTIVES

Primary central nervous system anaplastic large cell lymphoma, anaplastic lymphoma kinase positive (primary CNS ALCL, ALK+) is a rare CNS lymphoma whose description is limited to case reports. These tumors have a variable clinical course, and prognosis is primarily determined by age. We present the largest case series to date of primary CNS ALCL, ALK+, with observational data.

METHODS

A retrospective search of multiple academic centers was performed to identify cases of primary CNS ALCL, ALK+. We also performed a review of published cases of primary CNS ALCL, ALK+. Clinical history, radiography, pathology, and genetic testing data were obtained to determine the prognostic implications in the context of clinical course.

RESULTS

We identified three cases of primary CNS ALCL, ALK+ from our databases. A literature review identified 30 published reports of 31 individual cases. Clinical features for the combined 34 cases included a median age of 18.5 years, with a male to female ratio of 4.7:1, and the most common symptom was headache. Genetic studies demonstrated an ALK rearrangement by fluorescence in situ hybridization, and a gene fusion assay confirmed an NPM1-ALK gene fusion in one case.

CONCLUSIONS

We present the largest case series to date of a rare primary CNS lymphoma with additional diagnostic and clinical information.

Diagnosis, prevention and treatment of central nervous system involvement in peripheral t-cell lymphomas

Non-Hodgkin lymphomas with T-cell immunophenotype encompass a heterogeneous group of infrequent neoplasms that follow variable clinical courses but prevalently include aggressive behavior and high mortality rates. The involvement of the central nervous system (CNS) is an uncommon event in T-cell lymphomas, with wide variability among the different disease entities. CNS can be affected either at initial diagnosis or at recurrence, and both forms are considered "secondary CNS T-cell lymphoma". Given the low incidence of secondary CNS T-cell lymphoma, related literature is sparse, contradictory, and primarily constituted by small case series and single case reports. However, reported studies uniformly suggest high mortality rates related to this event. Therefore, to improve our ability to identify high-risk patients and offer them successful CNS prophylaxis or timely and effective treatment once the event has occurred may prevent CNS-related T-cell lymphomas deaths. For example, some entities like aggressive adult T-cell leukemia/lymphoma, extranodal natural killer/T-cell lymphoma, and other peripheral T-cell lymphomas with involvement of two or more extranodal organs are prone to CNS dissemination and should be considered for personalized CNS prophylaxis. The level of evidence suggesting an increased risk of CNS recurrence for other T-cell lymphomas and for other risk factors is lower. Published case series show that, following the example of aggressive B-cell lymphomas, patients with T-cell lymphomas and putative increased CNS risk receive different forms of prophylaxis, mostly methotrexate and cytarabine delivered by intrathecal and/or intravenous routes, with varied success. To date, achievements in the treatment of CNS involvement in patients with aggressive B-cell lymphoma were not replicated in secondary CNS T-cell lymphomas, and identification of effective therapies remains an urgent research target. This review is focused on clinical findings, diagnosis, treatment, and prognosis of patients with T-cell lymphoma experiencing CNS dissemination either at presentation or relapse. It aims to provide logical and, oftentimes, evidence-based answers to the most common questions on the most probable risk factors to CNS involvement in patients with T-cell lymphoma, the indications and strategies to prevent this life-threating event, and the management of patients with CNS disease.

Clinical Features and Prognostic Factors for Primary Anaplastic Large Cell Lymphoma of the Central Nervous System: A Systematic Review

Simple Summary

Primary anaplastic large cell lymphoma (ALCL) of the central nervous system (CNS) is a subtype of primary central nervous system lymphoma (PCNSL). ALCL is divided into anaplastic lymphoma kinase (ALK)-positive ALCL and ALK-negative ALCL, according to ALK expression. ALK-positive cancers tend to develop at a younger age and tend to have a better prognosis. Almost all past articles on primary ALCL of the CNS have been case reports and there have been no randomized trials or cohort studies on this subject. We thus performed a systematic review of primary ALCL of the CNS. According to the author’s survey, 36 case reports have been published in English-language journals. In this paper, we have summarized the clinical features and prognostic factors for primary ALCL of the CNS based on previous studies.

Abstract

Primary anaplastic large cell lymphoma (ALCL) of the central nervous system (CNS) is a subtype of primary CNS lymphoma (PCNSL). There are very few comprehensive reports on this extremely rare tumor. Therefore, it is necessary to investigate the clinical features and prognostic factors for primary ALCL of the CNS. We performed a systematic review of the published literature. Past cases were comprehensively searched using PubMed, Cochrane Library, and Web of Science. Clinical information, such as age, sex, anaplastic lymphoma kinase (ALK) status, lesion sites, treatment methods, and survivorship were extracted. Thirty-nine cases with information on ALK status and treatment course were identified. The average observation period was 13 months, and the overall 2-year survival rate was 58%. Univariate analyses showed a statistically significantly better prognosis among patients < 40 years of age (p = 0.039, HR 0.32 (0.11–0.95)) and in relation to ALK positivity (p = 0.010, HR 0.24 (0.08–0.71) and methotrexate treatment (p = 0.003, HR 0.17 (0.05–0.56)). Because of the sparsity of cases, it is necessary to accumulate cases in order to perform more detailed analyses.

Primary anaplastic large cell lymphoma of the central nervous system in a child: A case report

INTRODUCTION

To report the clinical characteristics of primary central nervous system T-cell lymphoma with anaplastic lymphoma kinase-1 (ALK-1) positive in an 8-year-old male.

PATIENT CONCERNS

The patient presented cognitive impairment, dizziness, vomiting, fever, and convulsions during the disease, followed by progressive and persistent severe headache, progressive increase of intracranial pressure, indifference, disorder of consciousness, mild increase in white blood cells in cerebrospinal fluid, progressive decrease of sugar, progressive increase of protein, abnormal signal of left parietal-occipital, local meningeal enhancement, and cerebrospinal fluid cytology.

DIAGNOSIS

He was diagnosed with ALK-1-positive central nervous system T-cell lymphoma.

INTERVENTIONS

Meropenem and vancomycin were administered to counter the infection, while dexamethasone alleviated the inflammation.

OUTCOMES

The patient died of cerebral hernia due to intracranial hypertension in the eighth week of the disease.

CONCLUSIONS

PCNS ALK-1-positive anaplastic large cell lymphoma is extremely rare. Also, it is difficult to distinguish from central meningeal lymphoma and central nervous system infection, which might lead to delayed diagnosis. However, early diagnosis depends on the pathological diagnosis of brain tissue biopsy.

[A case of primary central nervous system anaplastic lymphoma kinase positive anaplastic large cell lymphoma manifested as a unilateral pachymeningits]

There have been 23 reports of primary central nervous system anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma in the literature. Here we report the 24th case of a 40-year-old man who presented with occipital headache for one month. His contrast-enhanced brain MRI showed enhancement around the right temporal lobe, which suggested a diagnosis of hypertrophic pachymeningitis. He improved with steroid therapy. After discharge, however, he was readmitted with generalized convulsive seizures. Finally, he was diagnosed as primary central nervous system ALK-positive anaplastic large cell lymphoma by brain biopsy. Primary central nervous system lymphoma invading dura matter can rarely manifests as a unilateral pachymeningitis. Therefore, in case of pachymeningitis, we should pay attention to the possibility of infiltration of lymophoma with meticulous clinical follow-up.

How we diagnose and treat vitreoretinal lymphoma

The eye is a rare site for the development of malignant lymphoma. Based on cell type and involved intraocular structures, which as a whole represent an immune-privileged site, several subtypes of primary intraocular lymphoma need to be discerned. Primary vitreoretinal lymphoma (PVRL), the most common form, is an aggressive B-cell malignancy and considered a subtype of primary central nervous system (CNS) lymphoma. Ocular symptoms are non-specific and often mimic uveitis, frequently resulting in delayed diagnosis. Bilateral ocular involvement and dissemination/relapse in the CNS are common. Diagnosis of PVRL is usually based on the analysis of vitreous biopsy material. In addition to cytological and immunocytochemical examination, measurements of cytokine levels and molecular determination of B-cell clonality and recurrent mutations increase the diagnostic yield. Both systemic chemotherapy and exclusively local treatment, including ocular radiotherapy and intravitreal chemotherapy, are successful approaches for the management of PVRL, although it is currently not predictable which patients require systemic treatment in order to avoid cerebral dissemination, a complication associated with a considerably worse prognosis.

Primary CNS T-cell Lymphomas: A Clinical, Morphologic, Immunophenotypic, and Molecular Analysis

Primary central nervous system (CNS) lymphomas are relatively rare with the most common subtype being diffuse large B-cell lymphoma. Primary CNS T-cell lymphomas (PCNSTL) account for <5% of CNS lymphomas. We report the clinical, morphologic, immunophenotypic, and molecular characteristics of 18 PCNSTLs. Fifteen cases were classified as peripheral T-cell lymphoma, not otherwise specified, 2 of which were of γδ T-cell derivation and 1 was TCR silent; there was 1 anaplastic large cell lymphoma, ALK-positive and 2 anaplastic large cell lymphoma, ALK-negative. Median age was 58.5 years (range, 21 to 81 y), with an M:F ratio of 11:7. Imaging results showed that 15 patients had supratentorial lesions. Regardless of subtype, necrosis and perivascular cuffing of tumor cells were frequently observed (11/18 cases). CD3 was positive in all cases but 1; 10/17 were CD8-positive, and 5/17 were CD4-positive. Most cases studied had a cytotoxic phenotype with expression of TIA1 (13/15) and granzyme-B (9/13). Polymerase chain reaction analysis of T-cell receptor γ rearrangement confirmed a T-cell clone in 14 cases with adequate DNA quality. Next-generation sequencing showed somatic mutations in 36% of cases studied; 2 had >1 mutation, and none showed overlapping mutations. These included mutations in DNMT3A, KRAS, JAK3, STAT3, STAT5B, GNB1, and TET2 genes, genes implicated previously in other T-cell neoplasms. The outcome was heterogenous; 2 patients are alive without disease, 4 are alive with disease, and 6 died of disease. In conclusion, PCNSTLs are histologically and genomically heterogenous with frequent phenotypic aberrancy and a cytotoxic phenotype in most cases.

High-dose methotrexate monotherapy followed by radiation for CD30-positive, anaplastic lymphoma kinase-1-positive anaplastic large-cell lymphoma in the brain of a child

The authors report the case of an 11-year-old immunocompetent boy with primary CNS CD30-positive anaplastic large-cell lymphoma (ALCL) that was also positive for anaplastic lymphoma kinase-1. His initial clinical manifestation was acute meningitis of unknown etiology. Findings on CT scanning were normal. Although he received empirical treatment against infection, his systemic and neurological status deteriorated. Subsequent MRI revealed newly emerged enhanced lesions and concomitant edema in the left parietal lobe. Diagnosis was confirmed following a brain biopsy and immunohistochemical staining. Three courses of systemic high-dose methotrexate (HD-MTX) treatment with 2-week intervals was started, followed by whole-brain radiation. His clinical course improved, and he has remained disease-free for more than 8 years without any additional treatment. Because ALCL originating in the brain is extremely rare and difficult to diagnose, no standard treatment has been established. This report suggests that systemic HD-MTX monotherapy can be an effective and worthwhile tailored therapeutic option for pediatric primary CNS ALCL.

Central nervous system involvement in anaplastic large cell lymphoma in childhood: results from a multicentre European and Japanese study

In an international study of systemic childhood ALCL, 12/463 patients had CNS involvement, three of which had isolated CNS disease. Comparative analysis of CNS positive and negative patients showed no difference in ALK positivity, immunophenotype, presence of B symptoms or other sites of disease. The lymphohistiocytic variant was over represented in the CNS positive group (36% vs. 5%). With multi-agent chemotherapy, including high dose methotrexate, Ara-C and intrathecal treatment, the event free and overall survival of the CNS positive group at 5 years were 50% (95%CI, 25-75%) and 74% (45-91%), respectively with a median follow up of 4.1 years.

Clinical presentation of anaplastic large-cell lymphoma in the central nervous system

The majority of primary central nervous system (CNS) lymphomas are diffuse large B-cell lymphomas (DLBCLs) and anaplastic large-cell lymphoma (ALCL) is a type of T-cell tumor that is rare in the CNS. The aim of this study was to elucidate the clinical presentation and standard therapy of ALCLs by investigating reported cases. Additionally, a case of anaplastic lymphoma kinase (ALK)-positive ALCL in a 20-year-old man who exhibited no recurrence for >5 years following high-dose methotrexate (HD-MTX) treatment was described. Twenty-six immunocompetent patients with ALCL of the CNS that were previously reported and 1 case of ALCL of the CNS treated at our hospital were investigated. Overall survival (OS) was analyzed in relation to survival factors such as age, ALK status and the treatment regimen. The male:female ratio of the patients was 19:8. Of the 27 patients, 13 (48.1%) were ALK-positive, 9 (33.3%) were ALK-negative and the ALK status was not determined in the remaining 5 patients (18.5%). ALK-positive ALCL occurred at a younger age (median age, 17 years) and exhibited a favorable course (5-year OS, 75.0%), whereas ALK-negative ALCL presented at an older age (median age, 65 years) and resulted in fatal outcomes (5-year OS, <12.5%). Similar to the findings for systemic ALCL, ALK positivity, age <40 years and chemotherapy are associated with long-term survival for ALCL of the CNS. Chemoradiotherapy including methotrexate is recommended for ALCL and the possibility of treatment with chemotherapy alone for ALK-positive ALCL is currently under consideration.

Primary central nervous system ALK positive anaplastic large cell lymphoma with predominantly leptomeningeal involvement in an adult

A 31-year-old Korean male presented with altered consciousness and severe headache. Brain MRI delineated focal leptomeningeal enhancement without any intracerebral lesions. Diagnosis was made based on a brain biopsy showing anaplastic large cell lymphoma (ALCL), immunohistochemical stains revealing positivity for anaplastic lymphoma kinase (ALK) and an absence of involvement in any other organs; specifically, the primary central nervous system ALK+ALCL. Complete remission was achieved following 5 cycles of systemic chemotherapy with a high dose of Methotrexate and a simultaneous 7 cycles of intrathecal triple chemotherapy. Diagnosis of primary leptomeningeal ALK+ALCL is challenging given its rarity and non-specific symptoms along with non-pathognomonic radiologic findings. We present the first case of primary leptomeningeal ALK-positive ALCL where the clinical course, pathologic characteristics and treatment modality are described as well as a review of literature.

Primary central nervous system anaplastic large-cell lymphoma mimicking lymphomatosis cerebri

Primary central nervous system lymphoma (PCNSL) is usually diffuse large B-cell lymphoma. Anaplastic large-cell lymphoma (ALCL) rarely occurs in the central nervous system. PCNSL always presents as single or multiple nodular contrast-enhancing mass lesions within T2-hyperintense areas on magnetic resonance imaging (MRI). Infrequently, diffuse infiltrating change with little contrast enhancement called lymphomatosis cerebri can be seen in PCNSL. In this report, we describe a 75-year-old immunocompetent man who had progressive dementia. On MRI, diffuse white matter lesions with little contrast enhancement were observed to gradually progress, which was clinically consistent with his worsening condition. A biopsy specimen revealed non-destructive, diffusely infiltrating, anaplastic large CD30-positive lymphoma, indicating a diagnosis of ALCL. After the biopsy, he was treated by whole brain irradiation (total 46 Gy) and focal boost irradiation (total 14 Gy). However, his performance status worsened and there was no symptom improvement. The patient died 8 months after symptom onset. The clinical course, diagnostic workup, pathologic correlates, and treatment outcomes are described herein.

An unusual case of primary anaplastic large cell central nervous system lymphoma: an 8-year success story

Primary central nervous system anaplastic large cell lymphoma (PCNS ALCL) is rare, with only three adult patients reported. We describe a patient with PCNS ALCL with the longest follow-up period so far reported. The patient was successfully treated with chemotherapy and radiotherapy. The patient is well, independent and in full-time employment and has no residual neurological deficit. He has normal mental status, has a full head of hair and has fathered a healthy child.

Unusual presentation of anaplastic large cell lymphoma with clinical course mimicking fever of unknown origin and sepsis: autopsy study of five cases

AIM

To describe a subset of cases with the unusual clinical and histomorphological presentation of anaplastic large cell lymphoma (ALCL) mimicking fever of unknown origin (FUO) and sepsis.

METHODS

A pathology database was searched using full term Systematized Nomenclature of Medicine codes for ALCL to identify 23ALCL cases from the period 1999-2006. Of those, five cases that did not have a correct premortem diagnosis were further analyzed to elucidate the reasons for delayed and incorrect pre-mortem diagnosis. The analyzed data included clinical presentation, duration of symptoms, duration of hospital stay, premortem presumed cause of death, white blood cell count, platelet count, anion gap and blood pH, liver enzymes (alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, alkaline phosphatase), lactate, coagulation tests (prothrombin time, partial thromboplastin time, fibrinogen, D-dimers), microbiology cultures, and radiology and surgical pathology reports. Autopsy reports were reviewed for description of major gross findings, initial clinical diagnosis, and cause of death.

RESULTS

Five fatal and pre-mortem unrecognized ALCL cases were characterized by rapid decline, with histologic findings showing predominantly extranodal involvement, intravascular lymphomatosis, and hemophagocytosis. The cases were also characterized by unusual clinical manifestations including a FUO, sepsis, and disseminated intravascular coagulation-like picture, lactic acidosis, hepatosplenomegaly, and absence of significant peripheral adenopathy.

CONCLUSIONS

There is a distinct group of ALCLs with unique and specific clinical, gross autopsy, and histopathologic findings. Recognition of this clinical variant may facilitate early detection and potentially timely diagnosis and therapy.

Non-solid oncogenes in solid tumors: EML4-ALK fusion genes in lung cancer

It is generally accepted that recurrent chromosome translocations play a major role in the molecular pathogenesis of hematological malignancies but not of solid tumors. However, chromosome translocations involving the e26 transformation-specific sequence transcription factor loci have been demonstrated recently in many prostate cancer cases. Furthermore, through a functional screening with retroviral cDNA expression libraries, we have discovered the fusion-type protein tyrosine kinase echinoderm microtubule-associated protein like-4 (EML4)-anaplastic lymphoma kinase (ALK) in non-small cell lung cancer (NSCLC) specimens. A recurrent chromosome translocation, inv(2)(p21p23), in NSCLC generates fused mRNA encoding the amino-terminal half of EML4 ligated to the intracellular region of the receptor-type protein tyrosine kinase ALK. EML4-ALK oligomerizes constitutively in cells through the coiled coil domain within the EML4 region, and becomes activated to exert a marked oncogenicity both in vitro and in vivo. Break and fusion points within the EML4 locus may diverge in NSCLC cells to generate various isoforms of EML4-ALK, which may constitute approximately 5% of NSCLC cases, at least in the Asian ethnic group. In the present review I summarize how detection of EML4-ALK cDNA may become a sensitive diagnostic means for NSCLC cases that are positive for the fusion gene, and discuss whether suppression of ALK enzymatic activity could be an effective treatment strategy against this intractable disorder.

Development of anaplastic lymphoma kinase (ALK) small-molecule inhibitors for cancer therapy

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase (RTK) involved in the genesis of several human cancers; indeed, ALK was initially identified in constitutively activated and oncogenic fusion forms--the most common being nucleophosmin (NPM)-ALK--in a non-Hodgkin's lymphoma (NHL) known as anaplastic large-cell lymphoma (ALCL) and subsequent studies identified ALK fusions in the human sarcomas called inflammatory myofibroblastic tumors (IMTs). In addition, two recent reports have suggested that the ALK fusion, TPM4-ALK, may be involved in the genesis of a subset of esophageal squamous cell carcinomas. While the cause-effect relationship between ALK fusions and malignancies such as ALCL and IMT is very well established, more circumstantial links implicate the involvement of the full-length, normal ALK receptor in the genesis of additional malignancies including glioblastoma, neuroblastoma, breast cancer, and others; in these instances, ALK is believed to foster tumorigenesis following activation by autocrine and/or paracrine growth loops involving the reported ALK ligands, pleiotrophin (PTN) and midkine (MK). There are no currently available ALK small-molecule inhibitors approved for clinical cancer therapy; however, recognition of the variety of malignancies in which ALK may play a causative role has recently begun to prompt developmental efforts in this area. This review provides a succinct summary of normal ALK biology, the confirmed and putative roles of ALK fusions and the full-length ALK receptor in the development of human cancers, and efforts to target ALK using small-molecule kinase inhibitors.

A virtual tissue bank for primary central nervous system lymphomas in immunocompetent individuals

Primary central nervous system lymphoma (PCNSL) is a rare form of extranodal non-Hodgkin's lymphoma with continuously increasing incidence in both immunosuppressed and immunocompetent individuals. PCNSL is a very aggressive tumor with a poor outcome, and its clinical outcome is much worse than for nodal lymphomas. Differently from lymphomas arising in lymph nodes or in other extranodal sites, the treatment of PCNSL remains very unsatisfactory. Current biologic knowledge of PCNSL is still limited and several fundamental questions remain to be answered. This is mainly due to the paucity of PCNSL material for adequate translational research. With the aim of providing biologic material to investigators interested in PCNSL, we have implemented a virtual tissue bank (VTB) for PCNSL in immunocompetent patients. After registration, the VTB is accessible via any web browser at www.ielsg.org. Only anonymous data are centralized at the website of the International Extranodal Lymphoma Study Group, whilst the pathologic material is maintained at the local pathology institutes.

Primary meningeal lymphoma of T-cell origin: a rare presentation of primary central nervous system lymphomas

Primary meningeal lymphoma is a rare clinical entity. Central nervous system infiltration by systemic lymphoma should always be excluded. Diagnosis can be difficult, and prognosis is usually poor. Most are of B-cell origin. We present the case of a young man with a primary meningeal lymphoma of T-cell origin. He was treated with systemic chemotherapy with high-dose methotrexate and cytarabine and intraventricular chemotherapy. He had a clinical improvement and a complete remission, with a long overall survival. There is no standard treatment for this rare disease. Traditionally, treatment has been based in craniospinal radiation therapy and intrathecal chemotherapy, with poor overall results. More recently, systemic chemotherapy with high-dose methotrexate has been advocated, which could avoid the long-term toxicity of craniospinal radiation therapy, and could improve the prognosis of these patients.

Highly aggressive ALK-positive anaplastic large cell lymphoma with a leukemic phase and multi-organ involvement: a report of three cases and a review of the literature

Anaplastic large cell lymphoma (ALCL) is an aggressive neoplasm of T- or null cell phenotype and is recognized as a distinct clinicopathologic subtype of non-Hodgkin lymphoma (NHL) in the revised World Health Organization (WHO) classification of hematopoietic neoplasms. It is rarely associated with leukemic phase. Most cases with leukemic involvement are the small cell variant of ALCL. These cases often lack the pleomorphism seen in the common variant of ALCL and may be misdiagnosed. We report a series of three patients who presented with leukemic phase ALCL. The patients included an 11-year-old boy, a 29-year-old man, and a 59-year-old woman. The clinical and pathologic features of these cases are reviewed. The patients in our case series with leukemic phase ALCL exhibited rare clinical features. The patients presented with massive extranodal disease involving cerebrospinal fluid (CSF), liver, spleen, lungs, and bone marrow. CSF involvement was documented morphologically as well as by flow cytometry in two patients. Two of the patients had small cell variant and the third patient had common type ALCL. The neoplastic cells in all three patients were ALK positive; however these patients died within months of diagnosis. Leukemic phase ALCL is rare, and behaves in an aggressive manner. Some, but not all, cases in the literature presenting with peripheral blood involvement had small cell variant ALCL, as seen in two of our cases. The leukemic phase of ALCL should be considered when a T-cell leukemia with unusual morphologic features is encountered.

Primary cerebral ALK-1-positive anaplastic large cell lymphoma in a child. Case report and literature review

A 4-year-old African American male was referred to the Pediatric Neurosurgery Service for evaluation of new onset seizures and worsening mental status. An MRI of the brain revealed a pineal region mass with diffuse leptomeningeal enhancement and compression of the basilar cisterns. A biopsy of the brain revealed histologic and immunophenotypic findings characteristic of ALK-1+ anaplastic large cell lymphoma (ALCL). ALCL rarely occurs in the central nervous system and poses a significant diagnostic challenge often leading to a delay in the initiation of appropriate treatment. We describe a case of a rapidly deteriorating clinical course in a child with central nervous system ALCL and review the current literature on ALCL occurring in the central nervous system.

Rare pathological variants and presentations of primary central nervous system lymphomas

Primary central nervous system lymphoma (PCNSL) is a rare form of primary brain neoplasm, accounting for less than 3% of all primary brain tumors. Ninety percent of cases involve a large B-cell lymphoma that presents as a homogeneously enhancing lesion or lesions, typically deep-seated in the brain parenchyma. The authors describe unusual pathological forms of PCNSLs, including low-grade, T-cell, and Burkitt types, and also rare presentations such as neurolymphomatosis and pituitary lymphomas.

Pathology of primary central nervous system lymphoma

✓ The understanding of primary central nervous system lymphoma (PCNSL) has lagged behind that of the much more common systemic, nodal lymphomas. Reasons for this include the relative rarity of PCNSL and the fact that these lesions differ in some ways from their histologically similar systemic counterparts. The purpose of this paper is twofold: first, the author provides concise descriptions of the pathological features of both common and uncommon types of PCNSL while discussing issues such as the confusion surrounding histological classification of PCNSLs, problems related to intraoperative diagnosis, and the appropriate diagnostic work up. Second, the author discusses a small number of molecular studies to demonstrate the great promise they offer. Such studies have already clarified some issues, including the category of lymphocyte from which the majority of PCNSLs are derived. Hopefully in the future these studies will help guide treatment decisions.

Meningeal tumors of childhood and infancy. An update and literature review

Meningeal derived tumors of the first 2 decades of life are often diagnostically challenging due to the wide morphologic spectrum encountered and the rarity of most individual entities. The 2 most common patterns include the dural/leptomeningeal-based mass and neoplastic meningitis. Both primary and secondary meningeal presentations may occur, either early or late in the course of various meningothelial, mesenchymal, embryonal, glial, hematopoietic, histiocytic, melanocytic, and inflammatory tumors. As in other areas of pediatric pathology, there are significant differences between this patient cohort and adults, differences which will be emphasized in this review.

Unusual Variants of Primary Central Nervous System Lymphoma

Rare variants of primary central nervous system lymphoma (PCNSL) include unusual sites of presentation (eg, neurolymphomatosis and primary leptomeningeal lymphoma) and uncommon pathologic entities. Neurolymphomatosis involves peripheral nerves and nerve roots in addition to systemic and central nervous system (CNS) sites. Diagnosis requires a high index of suspicion, and treatment incorporates the principles of therapy for systemic and CNS lymphoma. Primary leptomeningeal lymphoma can present with symptoms of raised intracranial pressure or cranial or spinal polyradiculopathies. Diagnosis can be made by examining cerebrospinal fluid and incorporating immunophenotyping and molecular pathology techniques. Treatment options include irradiation and intrathecal or systemic chemotherapy. The features of PCNSL of T-cell origin and indolent B-cell PCNSL also are discussed.

Primary CNS lymphoma of T-cell origin: a descriptive analysis from the international primary CNS lymphoma collaborative group

PURPOSE

To describe the demographic and tumor related characteristics and outcomes for patients with primary T-cell CNS lymphoma (TPCNSL).

PATIENTS AND METHODS

A retrospective series of patients with TPCNSL was compiled from twelve cancer centers in seven countries.

RESULTS

We identified 45 patients with a median age of 60 years (range, 3 to 84 years). Twenty (44%) had Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1. Twenty-six (58%) had involvement of a cerebral hemisphere and sixteen (36%) had lesions of deeper sites in the brain. Serum lactate dehydrogenase was elevated in 7 (32%) of 22 patients, and CSF protein was elevated in 19 of 24 patients (79%) with available data. The median disease-specific survival (DSS) was 25 months (95% CI, 11 to 38 months). The 2- and 5-year DSS were 51% (95% CI, 35% to 66%) and 17% (95% CI, 6% to 34%), respectively. Univariate and multivariate analyses were conducted for age (</= 60 v > 60 years), PS (0 or 1 v 2, 3, or 4), involvement of deep structures of the CNS (no v yes), and methotrexate (MTX) use in the primary treatment (yes v no). Only PS and MTX use were significantly associated with better outcome with hazard ratios of 0.2 (95% CI, 0.1 to 0.4) and 0.4 (95% CI, 0.2 to 0.8), respectively.

CONCLUSION

This is the largest series ever assembled of TPCNSL. The presentation and outcome appear similar to that of B cell PCNSL. PS 0 or 1 and administration of MTX are associated with better survival.

Early molecular detection of central nervous system relapse in a child with systemic anaplastic large cell lymphoma: case report and review of the literature

We report a case of anaplastic large cell lymphoma (ALCL) with central nervous system relapse in an 11-year-old boy. The relapse was suspected on morphologic examination of the cytospin preparations of the cerebrospinal fluid (CSF) with a WBC of 10 cells/microl. CSF relapse was confirmed using immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and reverse transcriptase-polymerase chain reaction (RT-PCR) for abnormal ALK expression or gene structure. The patient developed large intracranial metastases, despite systemic, and intrathecal chemotherapy. This case demonstrates the feasibility of detecting ALCL in paucicellular CSF specimens and suggests that even low CSF involvement can herald massive parenchymal disease.

Anaplastic lymphoma kinase proteins in growth control and cancer

The normal functions of full-length anaplastic lymphoma kinase (ALK) remain to be completely elucidated. Although considered to be important in neural development, recent studies in Drosophila also highlight a role for ALK in gut muscle differentiation. Indeed, the Drosophila model offers a future arena for the study of ALK, its ligands and signalling cascades. The discovery of activated fusion forms of the ALK tyrosine kinase in anaplastic large cell lymphoma (ALCL) has dramatically improved our understanding of the pathogenesis of these lymphomas and enhanced the pathological diagnosis of this subtype of non-Hodgkin's lymphoma (NHL). Likewise, the realisation that a high percentage of inflammatory myofibroblastic tumours express activated-ALK fusion proteins has clarified the causation of these mesenchymal neoplasms and provided for their easier discrimination from other mesenchymal-derived inflammatory myofibroblastic tumour (IMT) mimics. Recent reports of ALK expression in a range of carcinoma-derived cell lines together with its apparent role as a receptor for PTN and MK, both of which have been implicated in tumourigenesis, raise the possibility that ALK-mediated signalling could play a role in the development and/or progression of a number of common solid tumours. The therapeutic targeting of ALK may prove to have efficacy in the treatment of many of these neoplasms.