Flow cytometry as a diagnostic tool in lymphomatous or leukemic meningitis

Technological features of blast identification in the cerebrospinal fluid: A systematic review of flow cytometry and laboratory haematology methods

BACKGROUND

Involvement of the central nervous system (CNS) by acute leukemias (ALs) has important implications for risk stratification and disease outcome. The clinical laboratory plays an essential role in assessment of cerebrospinal fluid (CSF) specimens from patients with ALs at initial diagnosis, at the end of treatment, and when CNS involvement is clinically suspected. The two challenges for the laboratory are 1) to accurately provide a cell count of the CSF and 2) to successfully distinguish blasts from other cell types. These tasks are classically performed using manual techniques, which suffer from suboptimal turnaround time, imprecision, and inconsistent inter-operator performance. Technological innovations in flow cytometry and hematology analyzer technology have provided useful complements and/or alternatives to conventional manual techniques.

AIMS

We performed a PRISMA-compliant systematic review to address the medical literature regarding the development and current state of the art of CSF blast identification using flow cytometry and laboratory hematology technologies.

MATERIALS AND METHODS

We searched the peer reviewed medical literature using MEDLINE (PubMed interface), Web of Science, and Embase using the keywords "CSF or cerebrospinal" AND "blasts(s)".

RESULTS

108 articles were suitable for inclusion in our systematic review. These articles covered 1) clinical rationale for CSF blast identification; 2) morphology-based CSF blast identification; 3) the role of flow cytometry; 4) use of hematology analyzers for CSF blast identification; and 5) quality issues. 9 /L, which is much lower than the original machine count and platelet transfusion was warranted.

DISCUSSION

1) Clinical laboratory testing plays a central role in risk stratification and clinical management of patients with acute leukemias, most clearly in pediatric ALs; 2) studies focused on other patient populations, including adults and patients with AML are less prevalent in the literature; 3) improvements in instrumentation may provide better performance for the classification of CSF specimens.

CONCLUSION

Current challenges include: 1) more precisely characterizing the natural history of AL involvement of the CNS, 2) improvements in automated cell count technology of low cellularity specimens, 3) defining the role of flow MRD testing of CSF specimens and 4) improved recognition of specimen quality by clinicians and laboratory personnel.

Major Differences in Lymphocyte Subpopulations Between Cerebrospinal Fluid and Peripheral Blood in Non-Hodgkin Lymphoma Without Leptomeningeal Involvement: Flow Cytometry Evidence of a Cerebral Lymphatic System

Cerebrospinal fluid (CSF) flow cytometry has a crucial role in the diagnosis of leptomeningeal disease in onco-hematology. This report describes the flow cytometry characterization of 138 CSF samples from patients affected by non-Hodgkin lymphoma, negative for disease infiltration. The aim was to focus on the CSF non-neoplastic population, to compare the cellular composition of the CSF with paired peripheral blood samples and to document the feasibility of flow cytometry in hypocellular samples. Despite the extremely low cell count (1 cell/µl, range 1.0-35) the study was successfully conducted in 95% of the samples. T lymphocytes were the most abundant subset in CSF (77%; range 20-100%) with a predominance of CD4-positive over CD8-positive T cells (CD4/CD8 ratio = 2) together with a minority of monocytes (15%; range 0-70%). No B cells were identified in 90% of samples. Of relevance, a normal, non-clonal B-cell population was documented in 5/7 (71%) patients with primary central nervous system lymphoma at diagnosis (p<0.0001), suggesting a possible involvement of blood-brain barrier cell permeability in the pathogenesis of cerebral B-cell lymphomas. The highly significant differences between CSF and paired peripheral blood lymphoid phenotype (p<0.0001) confirms the existence of an active mechanism of lymphoid migration through the meninges.

Comparative Analysis of Flow Cytometry and Cytomorphology for Neuroblastoma Cell Detection in Effusion and Bone Marrow Specimens

Background：Neuroblastoma (NB) frequently metastasizes to the bone marrow (BM), pleural and peritoneal cavities. The detection of NB cells in the BM and effusion specimens is important in clinical staging. Objective: The aim of this study was to compare the ability of flow cytometry (FCM) and cytomorphology (CM) in detecting NB cells. Materials and methods：From 21 patients with suspected NB metastasis, BM and effusion specimens were analyzed by FCM and CM. Results：A total of 16 effusion (76.2%) and 9 BM (42.9%) specimens were classified by FCM as positive for malignancy. CM revealed 12 (57.1%) and 9 (42.9%) positive effusion and BM specimens, respectively. There were three effusions detected by CM but not by FCM. There was no significant differences between FCM and CM in the detection of NB cells in effusions (p = 0.344). Conclusions：FCM can be used as an adjunct to CM for the detection of NB cells in effusion specimens.

Performance Characteristics of Cerebrospinal Fluid Cytology: An Analysis of Responses From the College of American Pathologists Nongynecologic Cytopathology Education Program

CONTEXT

- Cerebrospinal fluid cytology is a critical diagnostic tool for the diagnosis of many conditions affecting the central nervous system.

OBJECTIVE

- To assess the performance characteristics of cerebrospinal fluid cytology samples by evaluating participant interpretations within the College of American Pathologists Nongynecologic Cytopathology Education program.

DESIGN

- Participant interpretations (N = 46 264) evaluated in the College of American Pathologists Nongynecologic Cytopathology Education Program were examined for concordance with the general category and with the reference diagnosis. Two nonlinear mixed models were used to analyze the concordance rates.

RESULTS

- The overall concordance rates for the general category and reference diagnosis were 92.1% and 81.0%, respectively. In the malignant category, the concordance rates with the reference diagnosis were lowest for diagnoses of nonhematopoietic small blue round cell tumors (54.8%) and metastatic malignancy (77.5%); the concordance rate with the reference diagnosis was highest for leukemia/lymphoma (94.0%). In the benign category, the concordance rate was lowest for normal cerebrospinal fluid reference diagnoses (58.6%), followed by acute and chronic inflammation (64.6%), fungal infection (80.8%), and macrophages (85.3%). Significant differences in concordance were uncovered when performance was evaluated by participant type and stain technique. Leukemia/lymphoma was the most common diagnosis for misclassified nonhematopoietic small blue round cell tumor cases and negative or inflammatory cerebrospinal fluid cases.

CONCLUSIONS

- This study illustrates the difficulties in achieving accurate diagnoses from cerebrospinal fluid specimens, particularly for nonhematopoietic small blue round cell tumors and normal and inflammatory cerebrospinal fluid specimens.

Assessment of the Utility of Cytology and Flow Cytometry of Cerebrospinal Fluid Samples in Clinical Practice

OBJECTIVES

We sought to assess the utility and limitations of both flow cytometry (FC) and cytology for the analysis of cerebrospinal fluid (CSF) in a practical clinical setting.

METHODS

A total of 393 consecutive CSF samples from 171 patients submitted for both cytomorphologic and FC assessments were analyzed.

RESULTS

Both FC and cytology findings were negative for malignancy in 315/393 samples (80%), and either positive (POS) or suspicious/atypical (SUSP/AT) in 7% of samples. This resulted in high agreement between FC and cytology (87%). Minor discrepancies were present in 4% of the cases. In 28 samples, an abnormal population was detected by FC but not by cytology.

CONCLUSIONS

FC and cytology are important complementary methods for analyzing CSF samples. In cases where cytology is SUSP/AT and FC is inconclusive or negative, additional specimens should be submitted for immunostaining, cytogenetics, and/or molecular studies.

Highly elevated serum lactate dehydrogenase is associated with central nervous system relapse in patients with diffuse large B-cell lymphoma: Results of a multicenter prospective cohort study

Central nervous system involvement remains a challenging issue in the treatment of patients with diffuse large B-cell lymphoma. We conducted a prospective cohort study with newly diagnosed diffuse large B-cell lymphoma patients receiving rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone to identify incidence and risk factors for central nervous system involvement. Among 595 patients, 279 patients received pre-treatment central nervous system evaluation, and 14 patients had central nervous system involvement at diagnosis (2.3% out of entire patients and 5.0% out of the 279 patients). For those patients, median follow-up duration was 38.2 months and some of them achieved long-term survival. Out of 581 patients who did not have central nervous system involvement at diagnosis, 26 patients underwent secondary central nervous system relapse with a median follow-up of 35 months, and the median time to central nervous system involvement was 10.4 months (range: 3.4–29.2). Serum lactate dehydrogenase > ×3 upper limit of normal range, the Eastern Cooperative Oncology Group performance status ≥ 2, and involvement of sinonasal tract or testis, were independent risk factors for central nervous system relapse in multivariate analysis. Our study suggests that enhanced stratification of serum lactate dehydrogenase according to the National Comprehensive Cancer Network-International Prognostic Index may contribute to better prediction for central nervous system relapse in patients with diffuse large B-cell lymphoma. This trial was registered at clinicaltrials.gov identifier: 01202448.

Higher levels of progranulin in cerebrospinal fluid of patients with lymphoma and carcinoma with CNS metastasis

Assessing central nervous system (CNS) involvement in patients with lymphoma or carcinoma is important in determining therapy and prognosis. Progranulin (PGRN) is a secreted glycosylated protein with roles in cancer growth and survival; it is highly expressed in aggressive cancer cell lines and specimens from many cancer types. We examined PRGN levels by Enzyme Immuno-Assay (EIA) in cerebrospinal fluid (CSF) samples from 230 patients, including 18 with lymphoma [12 with CNS metastasis (CNS⁺); 6 without CNS metastasis (CNS^-)], 21 with carcinomas (10 CNS⁺; 11 CNS^-), and 191 control patients with non-cancer neurological diseases, and compared PRGN levels among these disease groups. Median CSF PGRN levels in the CNS⁺ lymphoma group were significantly higher than in the CNS^- lymphoma and control non-cancer groups; and were also significantly higher in the CNS⁺ carcinoma group than in the CNS^- carcinoma and control groups, except for patients with infectious neurological disorders. Receiver operating characteristic curve analyses revealed that CSF PGRN levels distinguished CNS⁺ lymphoma from CNS^- lymphoma and non-cancer neurological diseases [area under curve (AUC): 0.969]; and distinguished CNS⁺ carcinomas from CNS^- carcinomas and non-cancer neurological diseases (AUC: 0.918). We report here, for the first time, that CSF PGRN levels are higher in patients with CNS⁺ lymphoma and carcinomas compared to corresponding CNS^- diseases. This would imply that measuring CSF PGRN levels could be used to monitor CNS⁺ lymphoma and metastasis.

Overview of cerebrospinal fluid cytology

Cerebrospinal fluid (CSF) cytology, i.e., the cytologic evaluation of its cellular composition, forms an integral part of the neurologist's armamentarium. Total and differential cell counts provide important first information across a spectrum of pathologic conditions involving the central nervous system and its coverings. CSF samples require immediate processing, ideally within 1 hour from collection. Upon centrifugation cytology is commonly assessed on May-Grunwald-Giemsa stains. Several additional stains are available for the identification of infectious agents such as bacteria or fungi, or the further specification of neoplastic cells by immunocytochemistry. The evaluation warrants familiarity with cytologic characteristics of cells across normal and diseased states. In normal CSF, lymphocytes and monocytes are encountered. A predominance of neutrophil granulocytes suggests bacterial meningitis and prompts search for intracellular bacteria. In contrast, in viral and chronic infections lymphocytes and monocytes prevail. Upon activation lymphocytes typically enlarge and eventually differentiate into plasma cells. Similarly, monocytes differentiate into macrophages that clear cellular debris. Macrophages that contain fragments of erythrocytes or hemoglobin degradation products are referred to as erythro- or siderophages, both of which indicate prior subarachnoid hemorrhage. Likewise, the detection of tumor cells is specific for neoplastic meningitis, although false-negative CSF cytologies are frequent. In summary, detailed morphologic workup of CSF samples provides valuable diagnostic information and is mandated in all cases with elevated cell count, computed tomography-negative suspected subarachnoid hemorrhage, and neoplastic meningitis. In all cases it needs to be interpreted in the clinical context and complements other clinical and laboratory findings.

Mantle Cell Lymphoma Presenting with Acute Bilateral Ophthalmoplegia

A 72-year-old woman presented with acute onset of double vision, bilateral complete blepharoptosis, and nearly complete ophthalmoplegia. Orbital and brain magnetic resonance imaging were normal. Further investigation revealed bicytopenia with hepatosplenomegaly. Liver biopsy revealed mantle cell lymphoma. Cytology later showed the presence of mantle cells in cerebrospinal fluid analysis. Her ophthalmoplegia improved from her first cycle of systemic and intrathecal chemotherapy. To the best of our knowledge, this is the second case in the literature of mantle cell lymphoma with central nervous system involvement presenting with ophthalmoplegia. This symptom should be considered one of the initial signs of mantle cell lymphoma.

Cerebrospinal fluid from patients with hematopoietic neoplasms: the need for an integrated approach

INTRODUCTION

Cerebrospinal fluid (CSF) evaluation plays an increasing role in the diagnosis and staging of hematopoietic neoplasms. The evaluation is based on the cytomorphologic evaluation (CE) of the specimen and flow cytometry study (FCS). The impact of the increased sensitivity of multicolor FCS and its correlation with the morphological analysis of CSF needs to be evaluated to better guide clinical management.

MATERIALS AND METHODS

CSF specimens sent for CE and FCS obtained over a 9-month period were retrospectively analyzed. Cases were considered completely discordant if one method detected an abnormal hematologic population and the corresponding method was negative and partially discordant if FCS detected an abnormal hematologic population and the CE was atypical or suspicious. Root cause analysis of these discrepancies was performed.

RESULTS

A total of 78 of 361 cases (22%) had discordant results; 72 cases were from patients with hematopoietic neoplasms-22 cases were completely discordant and 50 were partially discordant. FCS had a sensitivity of 95.3% and a specificity of 98.1% for detecting abnormal hematopoietic populations. CE rendered a positive diagnosis in 17.6% of cases with a specificity of 100%.

CONCLUSIONS

Our series demonstrates evaluation of CSF involvement by hematopoietic malignancy with FCS is more sensitive than and equally specific as CE. Nonetheless, CE remains one of the mainstays in the evaluation of CSF specimens. Optimizing cytologic evaluation through process modifications including decreasing screening area and evaluation of multiple preparations increased the detection rate of malignant cells. As such, optimal CSF evaluation and integration FCS is critical in patient management.

Clinical approach to diffuse large B cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is the most common subtype of lymphoma. We now recognize that DLBCL corresponds to a biologically heterogeneous family of diseases. Given the potential for cure for most DLBCL patients, appropriate diagnostic and staging evaluation and therapy are essential. Here we review areas of consensus as well as controversy in the evaluation, treatment and monitoring of patients with DLBCL and its related subtypes.

Neuropathies associated with lymphoma†

Neuropathy occurs with various manifestations as a consequence of lymphoma, and an understanding of the etiology is necessary for proper treatment. Advances in medical imaging have improved the detection of peripheral nerve involvement in lymphoma, yet tissue diagnosis is often equally important. The neoplastic involvement of the peripheral nervous system (PNS) in lymphoma can occur within the cerebrospinal fluid (CSF), inside the dura, or outside of the CSF space, affecting nerve root plexuses and peripheral nerves. The infiltration of either cranial or peripheral nerves in lymphoma is termed neurolymphomatosis (NL). These infiltrations can occur as mononeuropathy, multifocal neuropathy, symmetric neuropathies, or plexopathies. In rare cases, intravascular lymphoma (IL) can affect the PNS and an even rarer condition is the combination of NL and IL. Immune-mediated and paraneoplastic neuropathies are important considerations when treating patients with lymphoma. Demyelinating neuropathies, such as Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy, occur more frequently in non-Hodgkin's lymphoma than in Hodgkin's disease. Paraproteinemic neuropathies can be associated with lymphoma and paraneoplastic neuropathies are rare. While the treatment of lymphomas has improved, a knowledge of neurotoxic, radiotherapy, neoplastic, immune-mediated and paraneoplastic effects are important for patient care.

Detection of central nervous system involvement in childhood acute lymphoblastic leukemia by cytomorphology and flow cytometry of the cerebrospinal fluid

BACKGROUND

Therapy directed at the central nervous system (CNS) is an essential part of the treatment for childhood acute lymphoblastic leukemia (ALL). The current evaluation of CNS involvement based on cytomorphological examination of the cerebrospinal fluid (CSF) alone is not as sensitive with low cell counts as flow cytometric immunophenotyping (FCI) of the CSF. However, the importance of low CSF blasts counts at diagnosis is uncertain. We sought to determine the significance of FCI in relation to conventional morphological examination.

PROCEDURE

We retrospectively compared FCI of the CSF with cytomorphology at diagnosis or relapse of childhood ALL. All patients were diagnosed 2000-2012 in Stockholm or Umeå, Sweden. Clinical data were collected from medical records and the Nordic leukemia registry. Treatment assignment was based on morphological examination only.

RESULTS

The cohort was comprised of 214 patients with ALL. CSF involvement was detected by both methods in 20 patients, in 17 by FCI alone, and in one patient by cytomorphology alone. The relapse rate was higher for patients with negative cytology but positive FCI compared to those without CNS involvement using both methods. The difference was especially marked in the current protocol. However, none of the patients with negative CSF cytology but positive FCI had a CNS relapse.

CONCLUSIONS

FCI of the CSF increased the detection rate of CNS involvement of ALL approximately two times compared to cytomorphology. Patients with low-level CNS involvement may benefit from additional intensified systemic or CNS-directed therapy, but larger studies are needed.

Leptomeningeal involvement in B-cell chronic lymphocytic leukemia: a case report and review of the literature

BACKGROUND

Central nervous system involvement is considered a rare complication of chronic lymphocytic leukemia, and so there is the risk of being overlooked.

CASE PRESENTATION

We report a case of central nervous system involvement in a 75-year-old mulatto woman with chronic lymphocytic leukemia after 5 years of follow-up and a literature review on the subject. The clinical course, treatment and outcome are described. A systematic, meticulous and comprehensive analysis of existing publications regarding chronic lymphocytic leukemia with central nervous system involvement was performed.

CONCLUSION

We concluded that central nervous system involvement of chronic lymphocytic leukemia is probably not associated with any evident risk factors. Diagnostic approach differs by institutions but often includes imaging, morphology and flow cytometry. Resolution of central nervous system symptoms can usually be accomplished with intrathecal chemotherapy or irradiation followed by systemic treatment. The recognition of this entity by clinicians could lead to early detection and treatment, resulting in better outcomes in this rare complication.

Flow cytometric analysis of cerebrospinal fluid has low diagnostic yield in samples without atypical morphology or prior history of hematologic malignancy

OBJECTIVES

To identify pretest characteristics of cerebrospinal fluid (CSF) specimens that will allow the rational use of flow cytometric analysis (FCA) in the diagnosis of hematologic malignancy.

METHODS

Retrospective data were collected on 501 consecutive CSF samples submitted for FCA.

RESULTS

A positive diagnosis of hematologic malignancy was made in 41 specimens (8.2%). Blasts or atypical lymphocytes were noted on Wright-stained slides in 98% of FCA-positive specimens (40/41), and a history of a hematologic malignancy was present in 89% of specimens (34/38). All FCA-positive specimens had atypical morphology or history of hematologic malignancy. Four hundred six specimens (81%) were FCA negative. Of FCA-negative specimens, 7% (30/406) had atypical morphology, and 3% (12/404) had future central nervous system involvement seen within 30 days.

CONCLUSIONS

These data support a policy in which FCA of CSF is actively discouraged unless atypical lymphocytes or blasts are seen or a history of hematologic malignancy is present.

Staging and monitoring of childhood rhabdomyosarcoma with flow cytometry

Patients with metastatic rhabdomyosarcoma (RMS) have a poor prognosis. The detection of contaminating RMS cells in the bone marrow (BM) is important in clinical staging and risk assessment. The cytological examination of the BM remains the gold standard for the diagnosis of RMS, but has a limited sensitivity. In the present study, 32 BM and two cerebrospinal fluid (CSF) samples from 11 patients with suspected metastasis were analyzed by flow cytometry (FCM) with ganglioside D2 (GD2) conjugated with fluorescein isothiocyanate, cluster of differentiation (CD)90-phycoerythrin, CD45-peridinin chlorophyll protein and CD56-allophycocyanin monoclonal antibody cocktail in parallel to morphological examination at diagnosis or during treatment. Five samples (14.7%) were positive for RMS onup morphological examination. By FCM, 16 samples (47.1%) were positive for RMS. A significant difference was identified between the two methods. The four-color FCM assay successfully detected RMS cells in BM samples to a level of 0.01% (1 per 10⁴ cells). RMS cells demonstrated a phenotype with CD56⁺/CD90⁺/CD45⁻/GD2⁻ expression, which is different from the CD56⁺/CD90⁺/CD45⁻/GD2⁺ expression phenotype in neuroblastoma cells. The follow-up of four patients by FCM demonstrated that two patients became minimal residual disease-negative following two and four cycles of chemotherapy, respectively, and survived. The other two cases remained FCM-positive despite receiving four courses of chemotherapy and consequently succumbed to progressive disease. In addition, FCM analysis of the CSF samples from one patient confirmed a diagnosis of CSF metastasis with RMS. In conclusion, FCM may have a role not only in staging and monitoring the effects of therapy, but also in providing diagnostic confirmation of CSF metastasis with RMS.

A systematic approach to the diagnosis of suspected central nervous system lymphoma

Central nervous system (CNS) lymphoma can present a diagnostic challenge. Currently, there is no consensus regarding what presurgical evaluation is warranted or how to proceed when lesions are not surgically accessible. We conducted a review of the literature on CNS lymphoma diagnosis (1966 to October 2011) to determine whether a common diagnostic algorithm can be generated. We extracted data regarding the usefulness of brain and body imaging, serum and cerebrospinal fluid (CSF) studies, ophthalmologic examination, and tissue biopsy in the diagnosis of CNS lymphoma. Contrast enhancement on imaging is highly sensitive at the time of diagnosis: 98.9% in immunocompetent lymphoma and 96.1% in human immunodeficiency virus-related CNS lymphoma. The sensitivity of CSF cytology is low (2%-32%) but increases when combined with flow cytometry. Cerebrospinal fluid lactate dehydrogenase isozyme 5, β2-microglobulin, and immunoglobulin heavy chain rearrangement studies have improved sensitivity over CSF cytology (58%-85%) but have only moderate specificity (85%). New techniques of proteomics and microRNA analysis have more than 95% specificity in the diagnosis of CNS lymphoma. Positive CSF cytology, vitreous biopsy, or brain/leptomeningeal biopsy remain the current standard for diagnosis. A combined stepwise systematic approach outlined here may facilitate an expeditious, comprehensive presurgical evaluation for cases of suspected CNS lymphoma.

Central nervous system prophylaxis in patients with aggressive diffuse large B cell lymphoma: an analysis of 3,258 patients in a single center

Central nervous system (CNS) relapse continues to be a frequent and usually fatal complication in patients with diffuse large B cell lymphoma (DLBCL). Multiple factors identify the possibility of relapse and justify neurological prophylaxis; however, most of these have not been confirmed. Thus, the use of prophylaxis has not been defined. From 1988 to 2008, 3,258 patients with DLBCL with higher clinical risks and multiple extranodal involvement that have been treated with standard anthracycline-based chemotherapy: CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) or CHOP-R (CHOP plus rituximab) and that achieve complete response were retrospectively analyzed to assess the efficacy of CNS prophylaxis. One thousand five patients received different schedules for CNS prophylaxis, and 2,253 patients did not receive CNS prophylaxis. CNS relapse was similar in patients who receive prophylaxis (6 %) compared to patients who did not receive prophylaxis (5.9 %). Overall survival of patients who either receive or did not receive prophylaxis was not statistically significant: 49 % versus 53 % (p = 0.802). Thus, it seems that CNS prophylaxis did not improve outcome in this special setting of patients, and no prognostic factors to predict the presence of CNS relapse were identified. It is evident that multicentric studies are necessary to define the role of prophylaxis in order to prevent CNS relapse and that the therapeutic procedure will be carefully revised.

Diagnostic strategies to investigate cerebrospinal fluid involvement in haematological malignancies

Central nervous system (CNS) involvement is a fatal complication of certain haematological malignancies with an incidence as high as 25% in specific leukaemia/lymphoma subtypes. It is often accompanied by 'occult' cerebrospinal fluid (CSF) involvement at diagnosis, which is frequently missed by conventional cytology examination. Unfortunately, a diagnostic gold standard is yet unavailable since CSF morphology may be negative for malignant cells in up to 45% of patients with suspected meningeal involvement. New technologies such as flow cytometry, molecular genetics and newer biomarkers may improve sensitivity and specificity facilitating the diagnosis of CNS involvement as well as effective prophylaxis and successful treatment.

Flow cytometric detection of liposomal cytarabine in cerebrospinal fluid of patients treated with intrathecal chemotherapy

We report the unusual flow cytometric detection of liposomes in the cerebrospinal fluid of patients with aggressive non-Hodgkin's lymphoma and acute myeloid leukemia, treated with intrathecal liposomal cytarabine.