A parallel comparison of T-cell clonality assessment between an in-house PCR assay and the BIOMED-2 assay leading to an efficient and cost-effective strategy

Primary cutaneous gamma/delta T-cell lymphoma in Taiwan: A series of six cases with frequent solitary presentation and relatively indolent behavior

BACKGROUND

Primary cutaneous gamma/delta T-cell lymphoma (PCDG-TCL) is aggressive, frequently presenting as multiple plaques, tumors, and/or subcutaneous nodules.

METHODS

In this study, we conducted a retrospective study in a tertiary center in Taiwan to characterize this rare tumor.

RESULTS

We identified six patients. Five presented with a solitary lesion, including two with clinical impression of epidermal inclusion cyst or lipoma. Two of four evaluable cases exhibited epidermotropism, with one mimicking Pautrier microabscess. The neoplastic cells were pleomorphic and mostly medium- to large-sized. In all cases, the neoplastic cells expressed T-cell receptor (TCR)-γ and/or TCR-δ, with four co-expressing βF1. Two of these βF1+ cases co-expressed TCR-γ but not TCR-δ (two different clones). All were negative for Epstein-Barr virus (EBV), low stage, and treated with radiotherapy alone or combined chemotherapy and radiotherapy. In two patients, lymphoma relapsed in 3 and 7 months, respectively, and one patient died of the disease in 7 months. Four other patients were free of disease for 6 to 126 months.

CONCLUSION

PCGD-TCL cases in Taiwan are more commonly solitary, frequently with indolent courses. The two currently available TCR-δ clones alone might be insufficient to detect all tumors.

Granuloma With an Underlying Lymphoma: A Diagnostic Challenge and a Wider Histologic Spectrum Including Adult T-Cell Leukemia/Lymphoma

Granulomatous reaction is not uncommon in histopathology, with various etiologies in different organs and geographic regions. Lymphoma is one of the underlying causes of granuloma; and sometimes the neoplastic cells may be masked by the granulomatous reaction. In this report, we present our experience with 7 lymphoma cases of various histologic types with coexisting granuloma to show the diagnostic challenges. In all cases, a granulomatous reaction was simultaneously present with the neoplastic cells. The 7 cases included 3 cases of adult T-cell leukemia/lymphoma in the lymph node or skin including one coexisting with mycobacterial infection, 2 cases of classical Hodgkin lymphoma involving the liver, and 1 case each of systemic Epstein-Barr virus-positive peripheral T-cell lymphoma and a hepatic inflammatory pseudotumor-like follicular dendritic cell sarcoma. Three cases were initially misdiagnosed as reactive change or mycobacterial infection instead of lymphoma, and a wrong histologic lymphoma type was diagnosed in 1 case. In this report, we showed that granulomatous reaction might mask lymphomas of various histologic types; and a diagnosis of mycobacterial infection or sarcoidosis could not exclude the possibility of an underlying lymphoma. We emphasized the importance of detailed histologic examination with the aid of ancillary studies to reach a correct diagnosis and to avoid inappropriate management of the patients. Our study also broadened the spectrum of lymphoma types coexisting with granuloma.

A Simple and Practical Guide for Triaging Lymphocyte-rich Effusions for Ancillary Studies

Lymphocyte-rich effusions of the body cavities may represent a reactive/benign condition, primary effusion lymphoma, or systemic lymphoma with secondary malignant effusion, either as initial presentation or as a late complication. Cytomorphologic examination is essential and fundamental for diagnosis and may provide important clues to the nature of diseases. However, based on morphology alone, cytologic diagnosis of lymphocyte-rich effusions could be very challenging, particularly when the lymphocytes are small. Cytologists/cytopathologists might be uncertain when a lymphocyte-rich effusion specimen warrants a comprehensive hematopathologic workup. Herein we present a simple and practical algorithmic approach. On the basis of the cytomorphology of lymphocytes (small vs. large cells), presence or absence of cellular atypia, and clinical information (an earlier history or current lymphoma), the lymphocyte-rich effusion samples could be triaged for ancillary studies including immunophenotyping and molecular assays if indicated. Incorporation of cytomorphology, correlation with clinical information, and appropriate application of various ancillary techniques is mandatory for a correct diagnosis of lymphocyte-rich effusion specimens.

Evaluation of the polymerase chain reaction-based T-cell receptor β clonality test in the diagnosis of early mycosis fungoides

BACKGROUND

T-cell receptor (TCR) clonality may help establish a diagnosis of mycosis fungoides (MF). Routine clonality analysis is performed by using a polymerase chain reaction TCR- gamma assay, yet with this method, 10% to 50% of T-cell lymphomas escape detection. TCR- beta gene rearrangement is an additional assay. Data about its efficacy are controversial.

OBJECTIVE

To evaluate the role of TCR-β assay in the diagnosis of early MF.

METHODS

A retrospective study of 61 skin biopsies, 20 from patients with MF, 30 from patients suspected to have early MF, and 11 from patients with chronic inflammatory skin disease.

RESULTS

Monoclonality was detected in 16 of 20 (80%) MF cases: 15 (75%) with TCR-β and 12 (60%) with TCR-γ assay. Of the 30 suspected cases of early MF, 14 showed monoclonality with TCR-β, and only 5 of 14 showed monoclonality with TCR-γ assay. None of the chronic inflammatory condition samples showed monoclonality. Therefore, TCR-β clonality assay was more sensitive than TCR-γ in early MF (83% vs 43%; P = .002).

LIMITATIONS

This was a retrospective, relatively small study.

CONCLUSION

TCR-β showed a higher sensitivity rate compared with TCR-γ in early-stage MF. The combined use of the TCR-β and TCR-γ clonality tests can significantly improve the diagnosis rate of early-stage MF.

Malignant effusions from extranodal NK/T-cell lymphomas are frequently of anaplastic morphology with azurophilic granules and of T-cell lineage

BACKGROUND

Extranodal natural killer/T-cell lymphoma (ENKTL) nasal type is an extranodal lymphoma, with most cases arising from the prototypic nasal/upper aerodigestive tract and the cell of origin (COO) is frequently of NK cells. Effusion involvement by ENKTL is rare. The cytomorphological and immunophenotypical features and COO of effusion ENKTL are elusive.

DESIGN

We report four new cases of effusion ENKTL, reviewing the cytomorphological features and investigating their COO by immunohistochemistry for T-cell receptor (TCR) protein expression and clonality assay for TCR gene rearrangement. We also reviewed 12 additional cases of effusion ENKTL from the literature.

RESULTS

All our four cases showed anaplastic tumor cells with fine to coarse azurophilic granules, with the primary tumor organs from the prototypic sites (2), small intestine (1), or indeterminate (1). The COO was either T-cell (3) or NK-cell (1). Compiling our four cases with that from the literature, all 16 effusion ENKTL cases were Epstein-Barr virus-associated and the majority (83%; 10/12) originated from the nonprototypic sites. Five of six (83%) effusion ENKTL cases were of T-cell lineage. Prognosis was poor with a median survival time of only 2.4 months.

CONCLUSIONS

Our study revealed that ENKTL in the effusion might be characterized by anaplastic large cell morphology, cytoplasmic azurophilic granules, and a higher proportion of T-cell lineage as compared to de novo tumors arising from the prototypic sites. ENKTL rarely presented in effusion, which is associated with dismal outcome. Large international studies are warranted to validate these findings.

Primary mediastinal histiocytic sarcoma presenting as pleural effusion

Histiocytic sarcoma (HS) is a rare malignant neoplasm showing morphological and immunophenotypic features of mature tissue histiocytes. As HS may mimic non-Hodgkin lymphoma (NHL) pathologically, before the era of immunohistochemistry, many previously reported cases were misdiagnosed NHL. Up to date, there are only a few reports delineating the cytological features in fine-needle aspiration or bronchoalveolar lavage, but not in the effusion fluid yet. Herein, we report the case of a 61-year-old male with a mediastinal tumor presenting with malignant pleural effusion. The effusion cytology showed atypical epithelioid (histiocytoid) cells, both in loose clusters and a dispersed pattern, with scanty admixed inflammatory infiltrate. Distinct from the benign histiocytes, these tumor cells exhibited evident cytological atypia, including irregular nuclear contours, significant nuclear pleomorphism, brisk mitotic figures, and apoptotic bodies in the Papanicolaou stain. With the Liu stain, most tumor cells showed abundant blue-gray cytoplasm, some with small cytoplasmic vacuoles and formation of pseudopods. Subsequent biopsies of the tumor nodules in the right lower lung and pleura showed diffuse sheets of neoplastic cells expressing CD4, CD45, CD68, and lysozyme by immunohistochemistry, confirming the diagnosis. Usually subtyping the lymphoma in the effusion fluid is not an important issue since most patients already have previously confirmed lymphoma. In rare situation, like our patient, the disease may present initially as a malignant effusion. Immunophenotyping using cell blocks and/or excisional specimens is mandatory for a definitive diagnosis.

Identification of T-cell receptor expression in EBV-positive neoplastic cells in extranodal NK/T-cell lymphoma, nasal-type, and comparison with T-cell receptor gene rearrangement by BIOMED-2 assay

The cellular lineage of extranodal NK/T-cell lymphoma, nasal-type (ENKTL), is determined by expression of T-cell receptor (TR) or TR gene rearrangement. In ENKTL, from TR immunohistochemistry, it may often be difficult to decide whether TR-positive cells are tumor cells or not, especially when TR is expressed in a subset of tumor cells. To analyze TR expression pattern and TR rearrangement in T-lineage ENKTL, we performed double immunofluorescence staining for Epstein-Barr virus-encoded small RNAs (EBER)/T-cell receptor (TCR) βF1 and CD56/TCR βF1 in 12 cases of ENKTL that showed TCR βF1 expression in immunohistochemistry. TR gene rearrangement was analyzed using a commercial BIOMED-2 multiplex polymerase chain reaction system. Immunohistochemistry showed that all 12 cases expressed TCR βF1 in a wide range of infiltrating cells from 100% to <1%. Two of them expressed both TCR βF1 and TCR cγM1. EBER/TCR-βF1-positivity was confirmed in 10 cases by double staining. One case failed to show EBER/TCR-βF1-positive cells but showed a CD56/TCR βF1-positive result. Among 12 cases, 5 had poor-quality DNA, 3 of them showed no polymerase chain reaction product, and 2 cases showed nonspecific peak of low height. Five of 7 cases with good DNA quality demonstrated monoclonal TR gene rearrangement. Based on TR expression and TR gene rearrangement, 10 of 12 cases of ENKTL were decided as a T-lineage tumor. In conclusion, because of common TR silence and poor DNA quality, consideration of both immunohistochemistry and TR gene rearrangement is necessary to determine the lineage of ENKTL.

Aggressive natural killer-cell neoplasm presenting in the marrow: a report of two cases including one with gains of chromosomes 4q and 9p

Aggressive nature killer (NK)-cell neoplasm includes aggressive NK-cell leukemia (ANKL) and extranodal NK/T-cell lymphoma (ENKTL), nasal type. ANKL is rare and is characterized by a systemic neoplastic proliferation of NK-cells, usually with a leukemic presentation. ENKTL is a predominantly extranodal lymphoma, occurring mainly in the upper aerodigestive tract. Both are aggressive neoplasms strongly associated with Epstein-Barr virus (EBV). Here we report two patients with aggressive NK-cells neoplasms localized in the bone marrow (BM) who presented as prolonged fever, anemia, and thrombocytopenia. Both were treated initially as infectious disease. Imaging studies revealed splenomegaly without any nodular lesion or lymphadenopathy. BM examination revealed extensive involvement by EBV-positive NK-cells in both cases. Staging workup including nasal examination/biopsy was negative. Both patients passed away in a month. One case showed gains of chromosomes 4q and 9p by array comparative genomic hybridization. Both tumors were diagnostically challenging due to the unusual clinical presentation and absence of leukemic change, tumor mass or lymphadenopathy. Our cases demonstrate that lymphoma should be considered in patients with fever of unknown origin and bone marrow aspiration/biopsy should be performed as early diagnosis and novel therapeutic regimens may benefit these patients.

Extranodal natural killer/T-cell lymphoma, nasal type in Taiwan: a relatively higher frequency of T-cell lineage and poor survival for extranasal tumors

Extranodal natural killer (NK)/T-cell lymphoma, nasal type, is a predominantly extranodal lymphoma associated with Epstein-Barr virus occurring most frequently in the upper aerodigestive tract. There are limited reports on cellular origin and prognostic factors. We retrospectively investigated 73 cases with a median age of 54 years and a male-female ratio of 2.0:1. The upper aerodigestive tract (nasal group) was the most common site of involvement (51 cases; 70%). The other organs (n = 22; extranasal group) included the skin (12 cases; 16%) and gastrointestinal tract (5; 7%). Of the 70 cases with complete staging, 71% had stage I/II disease. All cases were positive for Epstein-Barr virus by in situ hybridization. Using immunohistochemistry and clonality assay for T-cell receptor gene rearrangement, these tumors were classified into NK (n = 39; 53%), T (n = 13; 18%), and indeterminate lineage (n = 21; 29%). The only clinicopathological difference among these 3 groups was rare CD5 expression in the NK-cell group. Nasal tumors were more frequently of NK-cell origin, and extranasal tumors were equally of either T- or NK-cell origin. The 5-year overall survival rate was 35.6%. The overall survival time was shorter in the extranasal group, although there was no statistical difference in age, sex, and histologic or immunophenotypic features between the 2 groups. Excluding the cases with indeterminate lineage, 75% of cases were of NK lineage; and 25%, T lineage. Extranasal tumors were more aggressive than their nasal counterparts. A prospective national study is warranted for a better understanding of the clinicopathological and genetic features of this uncommon tumor and the prognostic factors.

Induced pluripotent stem cell reprogramming by integration-free Sendai virus vectors from peripheral blood of patients with craniometaphyseal dysplasia

Studies of rare genetic bone disorders are often limited due to unavailability of tissue specimens and the lack of animal models fully replicating phenotypic features. Craniometaphyseal dysplasia (CMD) is a rare monogenic disorder characterized by hyperostosis of craniofacial bones concurrent with abnormal shape of long bones. Mutations for autosomal dominant CMD have been identified in the ANK gene (ANKH). Here we describe a simple and efficient method to reprogram adherent cells cultured from peripheral blood to human induced pluripotent stem cells (hiPSCs) from eight CMD patients and five healthy controls. Peripheral blood mononuclear cells (PBMCs) were separated from 5-7 mL of whole blood by Ficoll gradient, expanded in the presence of cytokines and transduced with Sendai virus (SeV) vectors encoding OCT3/4, SOX2, KLF4, and c-MYC. SeV vector, a cytoplasmic RNA vector, is lost from host cells after propagation for 10-13 passages. These hiPSCs express stem cell markers, have normal karyotypes, and are capable of forming embryoid bodies in vitro as well as teratomas in vivo. Further differentiation of these patient-specific iPSCs into osteoblasts and osteoclasts can provide a useful tool to study the effects CMD mutations on bone, and this approach can be applied for disease modeling of other rare genetic musculoskeletal disorders.

Immunoglobulin heavy chain gene rearrangement in oral B cell lymphomas

OBJECTIVE

Oral non-Hodgkin lymphomas (NHLs) are an extensive group of malignant lymphoid cell neoplasms that are the second most common group of oral cancers. Subtyping NHL is important to plan for appropriate treatment, and the analysis of clonality is in many instances used for helping in the diagnosis of NHL. Thus, the aim of this study was to analyze immunoglobulin heavy chain (IgH) gene rearrangement in a series of oral B cell lymphomas to investigate the sensitivity of seminested polymerase chain reaction (snPCR).

STUDY DESIGN

Paraffin embedded tissue samples from 16 cases of oral B cell lymphomas were retrieved and subjected to snPCR to investigate the IgH gene rearrangement.

RESULTS

The results showed monoclonal IgH rearrangement in 85.7% of the cases studied, as represented by finding one band within the expected range of amplification.

CONCLUSIONS

This study found that snPCR is a consistent method for the detection of gene rearrangement in paraffin-embedded tissue.

A comparative study of flow cytometric T cell receptor Vβ repertoire and T cell receptor gene rearrangement in the diagnosis of large granular lymphocytic lymphoproliferation

INTRODUCTION

Large granular lymphocytes (LGLs) are medium- to large-sized lymphocytes with azurophilic cytoplasmic granules. Reactive vs. neoplastic LGLs are usually morphologically indistinguishable.

METHODS

We investigated 25 consecutive cases of LGL lymphoproliferation using flow cytometric T cell receptor Vβ (FC-Vβ) repertoire and T cell receptor gene rearrangement (TCR-GR) in detecting clonality.

RESULTS

Seventeen patients (68%) were T-LGL leukemia (T-LGLL) with a male predominance, a median age of 67, and a median absolute LGL count of 2.592 × 10(9) /L. All cases were clonal using the FC-Vβ analysis, and all but one (94%) was clonal by TCR-GR. Eight patients (32%) had reactive LGL lymphoproliferation. Two had EBV-associated infectious mononucleosis; one was clonal by both FC-Vβ and TCR-GR; and the other was clonal only by TCR-GR. The remaining six cases were polyclonal by both assays. Patients with reactive LGL lymphoproliferation were more frequently associated with an underlying/concurrent malignancy than those with T-LGLL (4/8 cases vs. 1/17; P = 0.023, Fisher's exact test). We compared the demographic, hemogram, and clonality data between these two groups and found that the only significant difference was the lower median platelet count in the LGL lymphocytosis group (201 × 10(9) /L vs. 223 × 10(9) /L; P = 0.031; Student's t-test). A literature review including the current study showed a high sensitivity of FC-Vβ analysis for T-LGLL (97.2%; 107/110 cases).

CONCLUSIONS

FC-Vβ analysis was slightly more sensitive than TCR-GR for the detection of clonal T cell lymphoproliferation. However, we must interpret the laboratory findings with clinical context as clonal T cell lymphoproliferation may occur in patients with viral infection.