Primary intraocular lymphoma: clinical, cytologic, and flow cytometric analysis.

PURPOSE: To compare cytologic with flow cytometric results of vitreous biopsy specimens obtained to rule out primary intraocular lymphoma (PIOL). STUDY DESIGN: Prospective noncomparative case series. PARTICIPANTS: Patients suspected of having PIOL who underwent vitreous biopsy were evaluated. METHODS: Patients underwent a standard 3-port vitrectomy and vitreous biopsy to rule out PIOL. Each undiluted specimen was split, and half was prepared for cytologic evaluation with the collodion bag method; the other half was submitted for flow cytometric immunophenotyping (FCI). The diluted specimen was processed as a cell block for cytology. MAIN OUTCOME MEASURES: Final diagnosis based on cytology and FCI. RESULTS: Ten of 14 patients had sufficient specimens for both cytologic and FCI evaluation. Three patients had chronic inflammation confirmed by both methods. Six patients had large cell lymphoma identified by both cytology and FCI. Two of those 6 patients initially had insufficient specimen for FCI. One patient had large cell lymphoma diagnosed cytologically that was initially negative for a clonal population by FCI. All lymphomas were B-cell type. CONCLUSIONS: Cytologic evaluation is an accurate diagnostic technique to evaluate for PIOL. FCI is useful for immunophenotyping PIOL. Multiple biopsies may be required to achieve a diagnosis.

Flow cytometry in the differential diagnosis of lymphocyte-rich thymoma from precursor T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma.

We compared the antigen expression profile of thymocytes in lymphocyte-rich thymoma with that of precursor T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma (T-cell ALL/LBL) cells using 4-colorflow cytometry. In all 15 thymoma cases, the thymocytes demonstrated 3 distinct subpopulations. The least mature cells (double-negative) expressed low-density CD2 and CD5, high-density CD7, CD10, CD34, and heterogeneous CD4 and CD8. They had the lowest density CD45 expression and were surface CD3-. The immature cells (double-positive) expressed CD2, CD5, CD7, CD4, CD8, heterogeneous surface CD3, and intermediate-density CD45. They were CD10- and CD34-. The mature cells (single-positive) expressed CD2, surface CD3, CD5, CD7, and CD4 or CD8. The heterogeneous expression of surface CD3, CD4, and CD8 also created a characteristic smearing pattern for these antigens. In all 15 T-cell ALL/LBL cases, the lymphoblasts formed a tight cluster without discrete subpopulations or smearing pattern. Of 5 double-negative cases, 4 demonstrated loss of CD2, CD10, or CD34 expression. Of 7 double-positive cases, 5 showed complete loss of surface CD3, CD2, and/or CD5; 4 were CD10+; and 2 were CD34+. Of 3 single-positive cases, 2 showed loss of CD2 and/or aberrant expression of CD34. Analysis of antigen expression pattern, the presence or absence of T cell-associated antigen deletion, and the expression of CD10 and CD34 by 4-color flow cytometry can help differentiate thymoma from T-cell ALL/LBL.

Immunophenotypic analysis of anaplastic large cell lymphoma by flow cytometry.

We studied the antigen expression profiles of 19 anaplastic large cell lymphoma (ALCL) cases by multiparameter flow cytometry. The neoplastic cells expressed CD45, HLA-DR, and CD30 in all cases. At least 1 T cell-associated antigen was expressed in each case (CD2, 12/17 [71%]; CD4, 12/19 [63%]; CD3, 6/19 [32%]; CD7, 6/19 [32%]; CD5, 5/19 [26%]; CD8, 4/19 [21%]). CD25 was expressed in 14 (88%) of 16 cases. CD13 was expressed unexpectedly in 8 (47%) of 17 cases. One CD13+ ALCL also was positive for CD33 and 2 others for CD15, CD19, CD20, CD22, CD14, and CD36 were not expressed. Anaplastic lymphoma kinase protein was detected in about 33% (3/9) of ALCLs examined by flow cytometric immunophenotyping (FCI); expression was validated by immunohistochemical analysis. Of 19 ALCL cases, 12 were diagnosed solely based on FCI findings in conjunction with morphologic evaluation of body fluid (1 case), fine-needle aspirate (3 cases), or excisional biopsy specimen (8 cases). The diagnoses of the remaining 7 cases were suggested strongly by FCI and confirmed by immunohistochemical analysis. FCI is useful to aid in diagnosis of ALCL, particularly along with fine-needle aspiration evaluation. ALCL with aberrant expression of myeloid antigens should not be mistaken for extramedullary myeloid tumor.

T-cell-rich B-cell lymphoma presenting in the spleen: a clinicopathologic analysis of 3 cases.

We review the clinical, pathologic, and molecular genetic features of 3 splenic T-cell-rich B-cell lymphomas and discuss their differential diagnosis. All patients presented with symptomatic splenomegaly and underwent diagnostic/therapeutic splenectomy. Microscopically, the spleen in all cases showed a micronodular proliferation of lymphoid cells. A proportion of the nodules demonstrated central hyalinization or sclerosis. There was also an exuberant extramedullary hematopoiesis. On immunohistochemical stain, the nodules consisted predominantly of small T cells with scattered large atypical B cells. The clonal nature of the atypical B cells was confirmed by polymerase chain reaction assays for immunoglobulin heavy-chain gene rearrangement. In the H&E sections, the differential diagnoses included Hodgkin's lymphoma, follicular lymphoma, peripheral T-cell lymphoma, and nonneoplastic granulomatous process. The presence of exuberant extramedullary hematopoiesis also raised the possibility of a chronic myeloproliferative disorder. The combined morphologic, immunohistochemical, and molecular genetic data are essential for a correct diagnosis of splenic T-cell-rich B-cell lymphoma.

Sensitivity and specificity of cerebrospinal fluid flow cytometry for the diagnosis of leukemic meningitis in acute lymphoblastic leukemia/lymphoma.

The presence of leukemic blasts detected by light microscopy in cerebrospinal fluid (CSF) establishes the diagnosis of leukemic meningitis in acute lymphoblastic leukemia/lymphoma (ALL). Flow cytometry immunophenotyping (FCI) is a very sensitive method that detects a minute number of aberrant cells, and is increasingly performed on CSF samples. We sought to determine the sensitivity and specificity of CSF FCI for the diagnosis of leukemic meningitis in ALL. Between November 2007 and August 2011, 800 CSF samples from 80 patients with ALL were available from diagnostic lumbar punctures (LPs; n = 80), follow-up LPs (n = 687) and at the time of relapse (n = 33). FCI was performed on 267 samples, and only identified aberrant cells in cytologically confirmed cases of leukemic meningitis. A blinded review of all cases with detectable CSF nucleated cells confirmed these findings. We conclude that CSF FCI has a 100% sensitivity and specificity for the detection of lymphoblasts. However, additional studies are needed to define the role this procedure plays in the diagnosis of leukemic meningitis.

Composite small lymphocytic lymphoma and extra-medullary myeloid tumor: a potential diagnostic pitfall.

Reported herein is a case of composite small lymphocytic lymphoma (SLL) and extramedullary myeloid tumor (EMT) occurring in the same lymph node. Routine morphologic examination revealed a diffuse proliferation of small mature lymphocytes with numerous irregularly dispersed nodules, closely resembling SLL with prominent proliferation centers or Richter's transformation. Flow cytometric immunophenotyping and immunohistochemical stains demonstrated the presence of SLL cells as well as myeloblasts, confirming the diagnosis of a composite SLL and EMT. Conventional cytogenetics and fluorescence in situ hybridization studies revealed inversion 16 chromosome involving the core binding factor beta and myosin heavy chain 11 genes, characteristic of acute myeloid leukemia with abnormal bone marrow eosinophils and inv(16) or t(16;16) [CBFbeta/MYH11]. In conclusion, the occurrence of SLL and EMT in the same lymph node is rare and multiparameter approach is essential for a definitive diagnosis.

Marginal zone B-cell lymphoma: a retrospective immunophenotypic analysis.

BACKGROUND: Marginal zone B-cell lymphoma (MZL) comprises three related yet biologically distinct subtypes--splenic MZL (SMZL), nodal MZL (NMZL), and extranodal MZL of MALT type (MALT). In cases without adequate morphology, immunophenotypic characterization by flow cytometric immunophenotyping (FCI) relies heavily on exclusion of other low-grade lymphomas. We performed a retrospective review of FCI studies of MZL to search for immunophenotypes specific for MZL and its subtypes. We compared these to follicular lymphoma (FL) as we were specifically interested in differentiating MZL from CD10 negative FL. DESIGN: FCI findings for MZL and FL cases were reviewed. Statistical analysis of patterns and intensity of antigen expression [mean channel fluorescence (MCF)] were performed. RESULTS: Thirty-one cases of MZL (7 SMZL, 6 NMZL, 15 MALT, 3 MZL not otherwise specified) and 31 cases of FL were identified. All expressed CD19, CD20, and CD45. Thirty-two percent of MZL and 77% of FL expressed CD38. Expression of CD11c was seen in 57% of SMZL and 8% of other MZL (P < 0.01). Statistically significant differences in antigen expression between MZL and FL were seen for CD10, CD11c, and CD38. CD19 expression was significantly brighter in MZL (mean MCF of 455.3) than in FL (mean MCF of 166.9) (P < 0.001). MCF for isotype controls and CD20 were similar for FL and MZL. CONCLUSIONS: MZL expresses typical pan-B-cell antigens. Expression of CD11c is highly associated with SMZL. Levels of CD19 expression in conjunction with CD11c and CD38 expression can distinguish MZL from CD10 negative FL.

Ocular adnexal lymphoid proliferations: clinical, histologic, flow cytometric, and molecular analysis of forty-three cases.

PURPOSE: To describe the clinical features, histologic findings, flow cytometric immunophenotypes, and molecular profiles of ocular adnexal lymphoid proliferations. STUDY DESIGN: Prospective noncomparative case series. PARTICIPANTS: Forty-three patients suspected of having ocular adnexal lymphoid proliferations were biopsied and prospectively evaluated. METHODS: Provisional diagnoses were made on the basis of routine histology and immunohistochemistry for B and T cells. Results of flow cytometric immunophenotyping (FCI) and molecular assessment using polymerase chain reaction for immunoglobulin heavy chain (IgH) and TCR gamma chain gene rearrangement and bcl-2/IgH translocation were then incorporated into a final diagnosis. Demographic and clinical outcome data were collected. MAIN OUTCOME MEASURES: Final diagnosis based on histology, flow cytometry, and polymerase chain reaction. RESULTS: Forty-three cases were studied. Final diagnoses included 17 lymphomas, 18 chronic inflammations, 4 reactive lymphoid hyperplasias, and 4 atypical lymphoid infiltrates. Preliminary evaluation accurately categorized all 43 cases as either lymphoma or nonlymphoma. FCI permitted more precise subclassification of the lymphomas according to the Revised European American Lymphoma (REAL) system of nomenclature as follows: eight marginal zone B cell (mucosa-associated lymphoid tissue type), three mantle cell, two follicular, three large cell, and one lymphoplasmacytoid lymphoma. FCI showed a clonal B cell proliferation in 94% (16 of 17) of the lymphomas; FCI identified a clonal B cell population in 4% (1 of 25) of cases of nonlymphomas. Molecular evidence of clonality was identified in 88% (15 of 17) of lymphomas, 39% (7 of 18) of chronic inflammations, and 50% (4 of 8) of reactive lymphoid hyperplasias and atypical lymphoid infiltrates. CONCLUSIONS: The histologic diagnosis of ocular adnexal lymphoid lesions is highly accurate when determined by an experienced pathologist. FCI refines the histologic diagnosis and classification. Results of molecular studies should be interpreted in conjunction with clinical, histologic, and immunophenotyping findings.

Anterior chamber infiltrates associated with systemic lymphoma: report of two cases and review of the literature.

PURPOSE: To describe the clinicopathologic features of two patients with systemic lymphoma who developed anterior chamber (AC) infiltrates of lymphoma cells. DESIGN: Two case reports and literature review. METHODS: The clinical and pathologic findings in two patients with AC infiltrates secondary to systemic B-cell lymphoma are reviewed. MAIN OUTCOME MEASUREMENTS: Clinical observation and cytologic/flow cytometric examination of the infiltrate after AC aspiration. RESULTS: One patient presented with uveal infiltration, an exudative retinal detachment and an AC infiltrate. Systemic evaluation revealed a follicular lymphoma involving several groups of lymph nodes. The second patient with a known history of abdominal lymphoma was found to have blurred vision, photophobia and an AC infiltrate. Flow cytometric analysis of the AC infiltrate in both patients showed phenotypes consistent with the patients' systemic lymphomas. CONCLUSIONS: A pseudohypopyon in an adult may represent either the initial manifestation or a later complication of systemic lymphoma, similar to what has been reported in acute leukemia.