Jerald Z. Gong

Value of CD23 Determination by Flow Cytometry in Differentiating Mantle Cell Lymphoma From Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma

Mantle cell lymphoma (MCL) and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) share many morphologic and immunophenotypic features. In addition to histomorphologic examination, it is customary to use the absence of CD23 to differentiate MCL from CLL/SLL, based primarily on reported comparisons of immunohistochemical staining of tissue sections. These findings are widely extrapolated to flow cytometric analysis, although available data are contradictory and not sufficiently detailed. We compared expression of CD23 by flow cytometry in 22 cases of MCL and 25 cases of CLL/SLL. Lymphoma cells in 12 of 22 MCLs were negative for CD23, and 10 showed dim expression. In contrast, none of 25 CLL/SLLs were negative for CD23, 4 were dimly positive, and 21 were moderately or brightly positive. Thus, a significant proportion of MCL exhibited overlap of CD23 expression in the low-intensity range with CLL/SLL. Clinically, there was no correlation between the intensity of CD23 expression and clinical stage at diagnosis or survival. These findings emphasize that by flow cytometry, MCL can be differentiated reliably from CLL/SLL using CD23 if negative expression is observed. However, with dimly positive expression, interpretation should be cautious.

Fine-Needle Aspiration in Non-Hodgkin Lymphoma Evaluation of Cell Size by Cytomorphology and Flow Cytometry

We studied 48 non-Hodgkin lymphoma (NHL) fine-needle aspiration (FNA) specimens with initial cytomorphology (CM) and flow cytometry (FC) and subsequent surgical biopsy of the same lesion to determine whether a reliable diagnosis of large cell lymphoma or large cell transformation could be made. CM was evaluated by examining 200 lymphocytes in each specimen. FC was performed by analyzing monoclonal or abnormal B-cell populations. Percentages of large cells were evaluated by CM and FC and results correlated with the histologic diagnosis. All small cell NHLs showed fewer than 40% large cells by CM and FC; 100% (9/9; FC) and 67% (6/9; CM) of diffuse large B-cell lymphomas demonstrated greater than 40% large cells. Variable numbers of large cells were detected in grade III follicular lymphoma, low-grade lymphoma with partial large cell transformation, and large B-cell lymphoma containing fewer than 10% neoplastic cells. By using combined CM and FC, large cell lymphoma and large cell transformation can be diagnosed reliably by FNA if greater than 40% large cells are present. Surgical biopsy is necessary when there is necrosis, fewer than 10% neoplastic cells by FC, or fewer than 40% large cells with clinical signs of transformation.

Burkitt lymphoma arising in organ transplant recipients: a clinicopathologic study of five cases.

We report five cases of Burkitt lymphoma arising in organ transplant recipients. There were four men and one woman with a mean age of 35 years. All were solid organ recipients with three renal, one liver, and one double lung transplantation. The time interval between organ transplantation and lymphoma averaged 4.5 years. Patients typically presented with high-stage disease with generalized lymphadenopathy and bone marrow involvement. Histology showed classic Burkitt lymphoma or atypical variant/Burkitt-like morphology. C-MYC rearrangement, including three cases with immunoglobulin heavy chain and two cases with lambda light chain, and Epstein-Barr virus were detected in all the cases. Additional chromosomal abnormalities were present in two of three cases and p53 mutation was found in one of three cases. Aberrant genotype and phenotype were frequently encountered, including minor monoclonal or oligoclonal T-cell populations and undetectable surface immunoglobulin light chain expression. Four patients received antilymphoma regimens, with combination chemotherapy (three patients) and/or Rituximab (three patients), in addition to reduction of immunosuppression. All four patients achieved complete remission. We conclude that posttransplant Burkitt lymphoma represents a characteristic clinicopathologic entity and occurs later after transplantation. Genotypic and phenotypic aberrations are often present. Rituximab may be an effective alternative to conventional combination chemotherapy in the treatment of a posttransplant Burkitt lymphoma.

Molecular and cytogenetic characterization of a novel translocation t(4;22) involving the breakpoint cluster region and platelet-derived growth factor receptor–alpha genes in a patient with atypical chronic myeloid leukemia

We report a case of BCR‐ABL‐negative atypical chronic myeloid leukemia (CML) with translocation t(4;22) (q12;q11.2) juxtaposing the breakpoint cluster region (BCR) and platelet‐derived growth factor receptor–alpha (PDGFRA) genes. The patient was a 57‐year‐old man with a history of stage IV diffuse large B‐cell lymphoma, status post–6 cycles of combination chemotherapy in 1999, who presented in August 2002 with enlarged lymph nodes, anemia, and marked leukocytosis (50 × 109 g/dL) consistent with a myeloproliferative disorder (MPD). A bone marrow biopsy showed granulocytic hyperplasia, neutrophilia, and mild eosinophilia. Initial cytogenetic evaluation by interphase FISH for BCR‐ABL, to rule out a translocation 9;22, showed a variant signal pattern consistent with rearrangement of BCR at 22q11.2, but not ABL at 9q34. Analysis of the patients cDNA by polymerase chain reaction (PCR) for BCR‐ABL was negative. Cytogenetic analysis showed an abnormal karyotype with rearrangement of chromosomes 4 and 22. PCR amplification and subsequent sequence analysis demonstrated an in‐frame 5′‐BCR/3′‐PDGFRA fusion in the patients cDNA. PDGFRA encodes a receptor tyrosine kinase and shares structural and organizational homology with the KIT and CSf1R receptor genes. However, although the incidence of MPD involving translocations of PDGFRB has been well established, to our knowledge there are only two previous reports describing a BCR‐PDGFRA fusion gene, in 3 patients diagnosed with atypical CML. Here, we report the molecular and cytogenetic characterization of a patient with BCR‐PDGFRA‐positive MPD who had a complete hematologic response after treatment with imatinib mesylate.

The Value of Fluorescence In Situ Hybridization and Polymerase Chain Reaction in the Diagnosis of B-Cell Non-Hodgkin Lymphoma by Fine-Needle Aspiration

CONTEXT Molecular genetic analyses have been predicted to improve the diagnostic accuracy of fine-needle aspiration of B-cell non-Hodgkin lymphoma. OBJECTIVE To determine the value of routine molecular genetic assays, polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH), in the diagnosis of B-cell non-Hodgkin lymphoma by fine-needle aspiration (FNA). DESIGN A multiparametric method, including cytology, flow cytometry, PCR, and FISH, was prospectively evaluated in the diagnosis of B-cell non-Hodgkin lymphoma by FNA. Aspirates from 30 consecutive patients with suspected hematolymphoid malignancies were collected. All aspirates were triaged through a uniform program including cell-size analysis, B- and T-cell clonality studies, flow cytometric immunophenotyping, and bcl-1 and bcl-2 gene rearrangements by PCR and FISH. After completion of FNA evaluations, FNA results were compared with diagnoses from prior or subsequent surgical biopsies. RESULTS Monoclonal B-cell populations were detected in 18 of 20 B-cell non-Hodgkin lymphomas by flow cytometry and PCR. bcl-1 gene rearrangement was detected in 2 of 2 cases of mantle cell lymphoma. bcl-2 rearrangement was detected in 5 cases including 4 of 4 low-grade follicular lymphomas and 1 transformed follicular lymphoma. By incorporating the results of molecular genetic and ancillary diagnostics, a definitive classification was reached in 12 cases of B-cell non-Hodgkin lymphoma by FNA, including all cases of low-grade follicular lymphoma (4/4) and mantle cell lymphoma (2/2) and approximately 50% of small lymphocytic lymphoma (2/4) and large B-cell lymphoma (4/8). Ten of the 12 cases with a final classification reached by FNA had either prior or follow-up surgical biopsies, and all 10 cases showed agreement between the diagnoses rendered on FNA and surgical biopsies. CONCLUSIONS With proper handling and management of specimens, FNA can routinely provide samples adequate for molecular genetic studies, in addition to cytomorphology and flow cytometry, making it possible to consistently render accurate and definitive diagnoses in a subset of B-cell non-Hodgkin lymphomas. By incorporating FISH and PCR methods, FNA may assume an expanded role for the primary diagnosis of B-cell non-Hodgkin lymphoma.

Posttransplant lymphoproliferative disorder following nonmyeloablative allogeneic stem cell transplantation.

Posttransplantation lymphoproliferative disorder (PTLD) is a well-recognized complication of conventional bone marrow/stem cell and solid organ transplantation. However, not much is known about PTLD following the more recently introduced nonmyeloablative allogeneic stem cell transplantation (NMST). This study reports the findings from two cases of PTLD following NMST and compares them to the one previously reported case. The donor origin of the PTLD was determined using short tandem repeat analysis, and B- and T-cell clonalities were evaluated by polymerase chain reaction. Two cases of PTLD evolved in a total of 70 patients who have undergone NMST at our institution from 1999 to 2003. Both patients received conditioning with Fludarabine/Cytoxan/Campath 1H (alemtuzumab, anti-CD52 antibody) and T-cell-depleted donor cells with Campath-1H. Both PTLDs were EBV positive (by immunohistochemistry and in situ hybridization) with diffuse large B-cell lymphoma morphology. Our findings indicate the incidence of PTLD following NMST is 3% (2 of 70 patients from our institution and 1 of 30 from the previously reported case). All three PTLDs arose 6 to 7 months after NMST and were rapidly fatal. The pathology of the PTLD in all cases was donor origin, EBV positive, diffuse large B-cell lymphoma.

Mediastinal Adenopathy, Lung Infiltrates, and Hemophagocytosis Unusual Manifestation of Pediatric Anaplastic Large Cell Lymphoma: Report of Two Cases

To date, only 1 report describes an anaplastic large cell lymphoma (ALCL) associated with hemophagocytosis in the pediatric population. To better characterize this unusual manifestation of ALCL, we identified 2 additional cases. Both patients had fever, cytopenia, decreased fibrinogen level, mediastinal or hilar adenopathy, minimal to no peripheral adenopathy, and lung infiltrates. Bone marrow biopsies and aspirates revealed striking hemophagocytosis but no ALCL. One patient fulfilled the criteria for hemophagocytic syndrome, but the other lacked 1 criterion. Both patients were initially given a misdiagnosis of infection-associated hemophagocytosis. Definitive diagnosis required lymph node biopsies that showed CD30+, anaplastic lymphoma kinase-l+ ALCL. Both tumors responded to standard lymphoma chemotherapy. One patient achieved complete remission, whereas the other patient died of complications after 2 cycles of therapy. These findings are similar to the first reported case and indicate that pediatric ALCL can manifest with an unusual constellation of symptoms consisting of hemophagocytosis, mediastinal or hilar adenopathy, and lung infiltrates.

CD52 expression in mantle cell lymphoma

Mantle cell lymphoma is one of the most difficult to treat of all the non-Hodgkins lymphomas. CAMPATH-1H, a humanized monoclonal antibody against the CD52 antigen, has been used with some success in other lymphoproliferative diseases, especially chronic lymphocytic leukemia. This report demonstrates that tumor samples from patients with mantle cell lymphoma express the CD52 antigen and suggests that CAMPATH-1H should be studied in patients with mantle cell lymphoma.