High prevalence of Wilms tumor 1 expression in multiple myeloma and plasmacytoma: A cohort of 142 Asian patients' samples.

Wilms tumor 1 (WT1) is a promising target antigen for cancer immunotherapy. However, WT1 protein expression and its clinical correlation in multiple myeloma (MM) patients are still limited. We, therefore, investigated WT1 expression in 142 bone marrow and plasmacytoma samples of MM patients at different stages of the disease by immunohistochemistry. The correlations between WT1 expression and clinical parameters or treatment outcomes were evaluated. The overall positive rate of WT1 expression was 91.5%; this high prevalence was found in both bone marrow and plasmacytoma samples, regardless of the disease status. Cytoplasmic WT1 expression was correlated with high serum free light chain ratio at presentation. However, no significant association between WT1 expression and treatment outcome was observed. This study confirms the high prevalence of WT1 expression in an Asian cohort of MM, encouraging the development of immunotherapy targeting WT1 in MM patients, particularly in those with extramedullary plasmacytoma or relapsed disease.

A Rare Case of Blastic Plasmacytoid Dendritic Cell Neoplasm in a Child Mimicking Lymphoma/Leukemia Cutis.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare tumor that affects elderly individuals and presents a poor prognosis. Skin is the most common site of involvement, accounting for 89% of the cases. Extracutaneous organs, especially bone marrow, lymph nodes, and peripheral blood, can be involved at the time of diagnosis. We report a case of BPDCN in a child, presenting with a cutaneous lesion mimicking lymphoma or leukemia cutis. The histologic findings revealed a dense diffuse infiltration by monomorphic agranular medium-sized blast cells with sparing of the grenz zone, whose first immunophenotypic profile raised the possibility of diagnosing B lymphoblastic lymphoma or leukemia. However, the absence of CD10 expression and strongly positive expression for CD4, CD56, CD45RA, and the plasmacytoid dendritic cell-associated antigens, including CD123, supported the definite diagnosis of BPDCN. The patient responded well to a systemic combination chemotherapy regimen, modified from the Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) protocol for anaplastic large cell lymphoma (ALCL), that differed from the established recommendation using ALL protocol. Owing to the patient's excellent treatment outcome, this regimen could represent an effective alternative regimen for BPDCN in children.

Cutaneous Involvement of Extranodal NK/T Cell Lymphoma, Nasal Type, a Clinical and Histopathological Mimicker of Various Skin Diseases.

BACKGROUND: Extranodal NK/T cell lymphoma, nasal type (ENK/T) with cutaneous involvement has various histopathological findings and diverse clinical manifestations. METHODS: A retrospective study of cutaneous involvement of ENK/T lymphoma between 2006 and 2018 was conducted. RESULTS: Twenty-two cases were eligible for this study. Twelve cases could be proven as secondary cutaneous involvement by ENK/T lymphoma, while the remaining could not be confirmed as primary cutaneous ENK/T lymphoma. The histopathological patterns included dermal and subcutaneous nodular infiltration pattern in 11/22 cases (50%), lobular panniculitis pattern in 6/22 cases (27.3%), interface dermatitis pattern in 4/22 cases (18.2%), and granulomatous dermatitis pattern in 1/22 case (4.5%). The median follow-up was 18.3 months. Overall, the one-year and five-year survival rates were 31.3% and 13.3%, respectively. CONCLUSIONS: A variety of histopathological patterns of cutaneous involvement by ENK/T lymphoma should be differentiated from other cutaneous lymphomas, dermatitis, and infection. When atypical medium or large-sized lymphoid cells are encountered within skin lesions, pathologists should realize these lesions can be ENK/T lymphoma, especially in cases with coexisting tumor necrosis or angioinvasion. A complete evaluation of the upper aerodigestive tract is mandatory to identify the occult primary site of ENK/T lymphoma before establishing primary cutaneous ENK/T lymphoma.

Concurrent myasthenia gravis-related cervical thymoma in a patient with diffuse large B-cell lymphoma: a case report.

BACKGROUND: Cervical thymoma is a rare thymic epithelial neoplasm. Evidence supports an increased risk of second primary malignancies in patients with thymoma. We report a rare case of a patient with synchronous cervical thymoma and diffuse large B-cell lymphoma. CASE PRESENTATION: An 81-year-old Thai woman was referred for further treatment of diffuse large B-cell lymphoma at Siriraj Hospital, Bangkok, Thailand. While waiting for a review of the original pathological examination of a mass in the left neck and a mass in the left arm, the attending physician noticed ptosis of the upper eyelids, which was proven to be caused by myasthenia gravis. The final pathology review confirmed that the arm mass was diffuse large B-cell lymphoma, but the neck mass was cervical thymoma, type B1, not diffuse large B-cell lymphoma. Interestingly, the patient reported that the arm mass had been present for 2 years, while the neck mass had grown rapidly in the past month. A diagnostic challenge had arisen when the initial morphological evaluation was not performed with care, causing the first pathologist to misinterpret that the neoplastic cells in both masses were the same. CONCLUSION: Concurrent cervical thymoma and diffuse large B-cell lymphoma were proven after a careful pathology review, leading to better clinical management.

Human herpesvirus 8-associated multicentric Castleman disease in a patient with advanced HIV infection: A case report.

RATIONAL: Multicentric Castleman disease (MCD) is a nonclonal lymphoproliferative disorder that is rarely reported from Southeast Asian countries. Here, we report a case of human herpesvirus 8 (HHV-8)-associated MCD in a patient with advanced human immunodeficiency virus (HIV) infection who presented with prolonged intermittent fever, urticarial rash, hepatosplenomegaly, and generalized lymphadenopathy. PATIENT CONCERNS: A 34-year-old man with advanced HIV infection who was in good compliance with his antiretroviral treatment regimen presented with intermittent fever, weight loss, marked hepatosplenomegaly, and generalized lymphadenopathy. Recurrent symptoms of high-grade fever, abdominal discomfort, pancytopenia, and high C-reactive protein level occurred for 16 months. DIAGNOSES: Histopathological findings of left inguinal lymph node revealed diffuse effacement of lymph node architecture with coexpression of HHV-8 latency-associated nuclear antigen 1 from immunohistochemical staining. The HHV-8 viral load was 335,391 copies/mL. INTERVENTIONS: The patient was treated initially with one dose of intravenous rituximab (375 mg/m2) followed by subcutaneous rituximab (1400 mg) weekly for 5 weeks. OUTCOMES: The patient's recurrent systemic symptoms subsided dramatically, and he has now been in remission for almost two years. LESSONS: HHV8-associated MCD remains a diagnostic challenge in advanced HIV disease and should be suspected in those with recurrent flares of systemic inflammatory symptoms. Lymph node histopathology is essential for diagnosis and for excluding clonal malignancy. HHV-8 viral load is also useful for diagnosis and for monitoring disease activity.

Disseminated histoplasmosis in a kidney transplant patient.

Patients with impaired cell-mediated immunity have a higher risk of developing histoplasmosis; however, histoplasmosis after solid organ transplantation is rare. In Thailand, histoplasmosis cases are sporadic, and most cases are associated with human immunodeficiency virus (HIV) infection. Herein, we report a case of disseminated histoplasmosis in a kidney transplant Thai recipient diagnosed by fungal staining of fungal culture from bronchoalveolar lavage and bone marrow biopsy. Liposomal amphotericin B was given followed by oral itraconazole. The patient's clinical condition was improved; however, his graft function was irreversibly declined. The majority of histoplasmosis cases after solid organ transplant presented with disseminated disease with pulmonary involvement. Even in a non-endemic area of histoplasmosis, suspected cases should be early diagnosed and promptly managed in order to reduce morbidity and mortality, especially in cell-mediated immunity defect patients like solid organ transplant recipients.

Subcutaneous Panniculitis-Like T-Cell Lymphoma Versus Lupus Erythematosus Panniculitis: Distinction by Means of the Periadipocytic Cell Proliferation Index.

The distinction between subcutaneous panniculitis-like T-cell lymphoma (SPTCL) and lupus erythematosus (LE) panniculitis is remarkably challenging. Rimming by lymphocytes with an elevated Ki-67 cell proliferation index has been forwarded as a potential diagnostic finding in biopsies of SPTCL but has not been rigorously compared with biopsies from patients with LE panniculitis. Nineteen and 17 examples of SPTCL and LE panniculitis, respectively, were evaluated for periadipocytic rimming by lymphocytes expressing Ki-67, CD8, and ßF1 and for attributes associated with LE, including clusters of CD123-positive cells. The identification of periadiopocytic rimming using Ki-67, CD8, and ßF1 held sensitivity of 79%, 100%, and 89.5% and specificity of 100%, 52.9%, and 88.2%, respectively (P < 0.01). CD123-positive cells were in both disorders. LE-like histopathology was commonly encountered in SPTCL. In conclusion, an elevated Ki-67 cell proliferation index with rimming is useful for distinguishing SPTCL from LE panniculitis. Notably, many features of LE panniculitis can also be encountered in SPTCL.

Non-Hodgkin lymphoma in South East Asia: An analysis of the histopathology, clinical features, and survival from Thailand.

Systemic reports on the descriptive epidemiology of non-Hodgkin lymphoma (NHL) from Southeast Asia are scarce. A nationwide multi-institutional registry was conducted to compare the histopathology, clinical features, and survival of Thai adult patients with NHL using large registries, especially those from Far East Asia (FEA). Using a web-based registry system, 13 major medical centers from the 4 geographic regions of Thailand prospectively collected, from 2007 to 2014, the diagnostic pathology, according to the World Health Organization classification, 2008, clinical features and survival of 4056 patients who were newly diagnosed with NHL. The median age of the patients was 56 years (range, 16-99 years). The male-to-female ratio was 1.3:1. From the total of 4056 patients, T/NK-cell lymphoma (TNKCL) accounted for 12.6% of cases, and 5.1% had human immunodeficiency virus-associated lymphoma. The four leading histological subtypes were diffuse large B-cell lymphoma, not otherwise specified (58.1%); follicular lymphoma (5.6%); extranodal mucosa-associated lymphoid tissue lymphoma (5.2%); and peripheral T-cell lymphoma, not otherwise specified (4.0%). With a median follow-up duration of 46.1 months, the median overall survival of B-cell NHL was significantly longer than that of patients with TNKCL (76.5 vs 28.8 months, P = .0001). Compared to FEA, the Thai registry had an approximately one-half lower relative frequency of TNKCL; the prevalence of extranodal mucosa-associated lymphoid tissue lymphoma was much lower than in Korea, and the frequency of extranodal TNKCL, nasal type, was strikingly low compared to China. It is concluded that while the median age of Thai patients with NHL was approximately a decade younger than for Caucasians, the long-term survival rates for most histological subtypes were comparable. While the histological distribution generally complied with the characteristic Asian features, some differences from FEA were observed.

Random skin biopsy in the diagnosis of intravascular lymphoma.

BACKGROUND: Random skin biopsy (RSB) is a method for diagnosis of intravascular lymphoma (IVL). However, the indications for RSB to diagnose IVL have not yet been established. The aim of this study was to determine the appropriate indications for RSB to diagnose IVL. METHODS: Thirty-two patients with fever of unknown origin (FUO) and without skin lesion underwent RSB for diagnosis of IVL. Clinical data, including fever, neurological symptoms, hematologic disorders, organomegaly, bone marrow (BM) study, hypoxemia and serum level of lactate dehydrogenase (LDH), were evaluated. RESULTS: Seven of 32 patients were definitively diagnosed with IVL. In addition to FUO, 2 IVL patients also suffered from dyspnea and neurological disorders. Patients who had FUO with accompanying hematologic disorders, high LDH, negative BM study and no lymphadenopathy or hepatosplenomegaly had a significant tendency to have IVL by RSB (P = .03). FUO with hypoxemia was also identified as a significant indication for RSB (P = .02). CONCLUSIONS: RSB is a reliable method for diagnosis of IVL, especially in patients with FUO and any 1 or more of the 4 following abnormalities: (1) hematologic abnormalities; (2) high serum LDH; (3) hypoxemia; and/or, (4) unusual neurological symptoms with co-existing hematologic abnormalities and without lymphadenopathy, hepatosplenomegaly or BM abnormality.

ALK-positive anaplastic large cell lymphoma undiagnosed in a patient with tuberculosis: a case report and review of the literature.

BACKGROUND: Due to a similarity between the features of lymphoma and the features of tuberculosis, lymphoma may go unrecognized and undiagnosed in patients with tuberculosis. CASE PRESENTATION: A 33-year-old Thai man presented to our center with typical clinical manifestations of tuberculous lymphadenitis, with negative tests for both acid-fast bacilli and fungi, and negative polymerase chain reaction for Mycobacterial tuberculosis complex. The disease was not responding to anti-tuberculosis treatment and he developed both pericardial effusion and progressive lymphadenopathy. Large lymphoma cells were evident in the pericardial effusion, and a review of the previous lymph node biopsies confirmed the existence of ALK-positive anaplastic large cell lymphoma and tuberculous lymphadenitis. Moreover, when the tests were repeated, he was found to be positive for both acid-fast bacilli and Mycobacterial tuberculosis complex. The presence of typical morphology of tuberculous lymphadenitis and inattentional blindness may explain why the presence of large lymphoma cells was overlooked in one of the previous lymph node biopsies. Our patient developed severe pneumonia with profound septic shock due to carbapenem-resistant Enterobacteriaceae and died within days. CONCLUSIONS: Given that tuberculosis and lymphoma can share common features, this case highlights the importance of thoroughly reviewing all foregoing relevant patient data (most notably pathology samples) in order to rule out the presence of lymphoma that may exist within the shadow of typical morphology of tuberculous lymphadenitis.

Clinical Significance of Bone Marrow Involvement as Confirmed by Bone Marrow Aspiration vs. Bone Marrow Biopsy in Diffuse Large B-cell Lymphoma.

BACKGROUND: In diffuse large B-cell lymphoma (DLBCL), bone marrow (BM) involvement confirmed by BM biopsy confers a poor prognosis. However, in clinical practice, there may be disagreement in results between BM biopsy and BM aspiration in determination of BM involvement. It is unknown which of BM biopsy or BM aspiration better correlates with clinical outcome. OBJECTIVE: To evaluate clinical outcome of BM involvement as confirmed by BM aspiration vs. confirmation by BM biopsy in patients with DLBCL. MATERIAL AND METHOD: Clinical data, treatment, and outcome of 126 DLBCL patients with available BM aspirate slides who attended the Hematology Clinic at Siriraj Hospital between January 1, 2007 and December 31, 2009 were reviewed. BM aspirate slides were revised and interpreted by hematologists. RESULTS: BM involvement was found in 12.7% (16/126) by BM biopsy and 24.6% (31/126) by BM aspiration. Regarding BM biopsy results, rates of complete remission (CR) among patients with unequivocal involvement, equivocal involvement, and without involvement were 75.0%, 57.1%, and 77.7%, respectively (p = 0.464). Two-year overall survival (OS) rates among the three groups were not significantly different (p = 0.663). Regarding BM aspiration results, CR rates among patients with unequivocal involvement, equivocal involvement, and without involvement were 80.6%, 75.8%, and 72.7% (p = 0.755). Two-year OS rates among the three groups were not significantly different (p = 0.118). In multivariate analysis, BM involvement as determined by either BM biopsy or BM aspiration was not associated with CR rate or 2-year OS rates. However, the International Prognostic Index (PI) and use of rituximab were found to be signifcantly associated with CR rate and OS. CONCLUSION: In patients with DLBCL, BM involvement confirmed by either BM biopsy or BM aspiration appears not to influence the rate of complete remission or 2-year overall survival.

Effects of Power and Time on Ablation Size Produced by Radiofrequency Ablation: In vitro Study in Fresh Human Placenta.

INTRODUCTION: Radiofrequency (RF) current has been clinically used to coagulate some solid tumors. We investigated the effects of RF on fresh placenta to determine the possibility of its prenatal application in placental tumors. MATERIALS AND METHODS: Total 196 fresh placentae were interstitially coagulated with a 2-cm RF needle at 14 power-duration combinations. We compared the horizontal length of coagulated area using ultrasound and microscopic measurements. Histological changes were also described. RESULTS: We did not observe any significant change in lesion size from different power levels (p = 0.104 and 0.242 for ultrasound and microscopic measurements, respectively). Mean ± SD lesion length after 5 and 10 min of exposure measured by microscopy are 16.00 ± 2.22 and 17.00 ± 1.82 mm, respectively (p < 0.001). Ultrasound consistently over-measured lesion size by 2.87 ± 3.45 mm. We also observed a collapse of large vessels on chorionic plate adjacent to the RF site. CONCLUSION: Our in vitro experiment demonstrated placental tissue coagulation and collapse of chorionic vessels from RF. Projecting the area of placental coagulation should be based on duration of RF exposure, and not on the power level. An in vivo animal study is needed before these data are translated into clinical practice.

Primary cutaneous NK/T-cell lymphoma, nasal type and CD56-positive peripheral T-cell lymphoma: a cellular lineage and clinicopathologic study of 60 patients from Asia.

Primary cutaneous, extranodal natural killer/T-cell lymphoma, nasal type (PC-ENKTL), is a rare Epstein-Barr virus (EBV)-associated neoplasm with poorly defined clinicopathologic features. We performed a multinational retrospective study of PC-ENKTL and CD56-positive EBV-negative peripheral T-cell lymphoma (PC-CD56+PTCL) in Asia in an attempt to elucidate their clinicopathologic features. Using immunohistochemistry for T-cell receptors (TCRs), in situ hybridization for EBV, and TCR gene rearrangement, we classified 60 tumors into 51 with PC-ENKTL (20 of NK-cell, 17 T-cell, and 14 indeterminate lineages) and 9 with PC-CD56+PTCL. Tumors of T-cell origin accounted for 46% of PC-ENKTLs with half of these cases being TCR-silent. As compared with T-lineage tumors, PC-ENKTLs of NK-cell lineage had more frequent involvement of regional lymph nodes and more frequently CD8-negative and CD56-positive. Cases of PC-ENKTL showed more frequent tumor necrosis, younger age, and a higher frequency of CD16 and CD30 expression than cases of PC-CD56+PTCL. CD56-positive T-lineage PC-ENKTL tumors (n=8) had more localized disease in the TNM (tumor-node-metastasis) staging and were more often of γδ T-cell origin compared with cases of PC-CD56+PTCL (n=9). PC-ENKTLs and PC-CD56+PTCLs were equally aggressive, with a 5-year overall survival rate of 25%. Tumor necrosis and CD16 expression may serve as useful surrogates for differentiating PC-ENKTL from PC-CD56+PTCL. A single lesion, an elevated lactate dehydrogenase level, and the presence of B symptoms were independent poor prognostic factors for PC-ENKTL in multivariate analysis. Further studies with more cases are warranted to delineate the clinicopathologic features and significance of EBV in these rare lymphomas.

Interobserver variation in classifying lymphomas among hematopathologists.

BACKGROUND: Lymphomas are common malignancies that have various subtypes with many overlapping histologic, immunophenotypic and genetic features. Therefore, discordance in classifying lymphoma among pathologists may be encountered. But this issue is not well characterized. We conducted the present study to demonstrate discordances among Thai hematopathologists as well as to highlight common arguing points for classifying lymphomas. METHODS: The 117 lymphoma cases were randomly retrieved and individually reviewed by 7 hematopathologists, members of the "Thai Hematopathologist Group," without knowing the original diagnoses. The consensus diagnoses were given from a discussion by all members. In each case, the diagnosis from each participant was compared with the consensus diagnosis and classified into 4 categories as follow: 1) concordance, 2) minor discordance, 3) major discordance and 4) serious discordance. RESULTS: There were approximately 11% discordances between original and consensus diagnoses. The average discordances among all pathologists according to minor, major and serious discordances were 10%, 3.5% and 0.3%, respectively. Diffuse large B-cell lymphoma had the least discordance (7%). Small biopsies had been found to increase discordances in some lymphoma subtypes. CONCLUSIONS: The present study reveals some degrees of interobserver variation in classifying of lymphoma by using the 2008 WHO classification among hematopathologists. Some types of lymphomas on small biopsies were found to have a significant higher discordance rate. This study also described some common diagnostic discordances regarded as potential pitfalls in classifying lymphomas. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_162.

Pathologic highlights of dengue hemorrhagic fever in 13 autopsy cases from Myanmar.

Vascular permeability, thrombocytopenia, liver pathology, complement activation, and altered hemostasis accompanying a febrile disease are the hallmarks of the dengue hemorrhagic fever/dengue shock syndrome, a major arthropod-borne viral disease that causes significant morbidity and mortality throughout tropical countries. We studied tissues from 13 children who died of acute dengue hemorrhagic fever/dengue shock syndrome at the Childrens' Hospital, Yangon, Myanmar. Dengue viral RNA from each of the 4 dengue viruses (DENVs) was detected by reverse transcriptase polymerase chain reaction in 11 cases, and dengue viral proteins (envelope, NS1, or NS3) were detected in 1 or more tissues from all 13 cases. Formalin-fixed and frozen tissues were studied for evidence of virus infection using monoclonal antibodies against DENV structural and nonstructural antigens (E, NS1, and nonsecreting NS3). In the liver, DENV infection occurred in hepatocytes and Kupffer cells but not in endothelial cells. Liver damage was associated with deposition on hepatocytes of complement components of both classical and alternative pathways. Evidence of dengue viral replication was observed in macrophage-like cells in spleens and lymph nodes. No dengue antigens were detected in endothelial cells in any organ. Germinal centers of the spleen and lymph nodes showed a marked reduction in the number of lymphocytes that were replaced by eosinophilic deposits, which contained dengue antigens as well as immunoglobulins, and complement components (C3, C1q, and C9). The latter findings had previously been reported but overlooked as a diagnostic feature.

Extranodal NK/T-cell lymphoma, nasal type, includes cases of natural killer cell and αß, γδ, and αß/γδ T-cell origin: a comprehensive clinicopathologic and phenotypic study.

Extranodal NK/T-cell lymphoma (ENKTL), nasal type, may be of NK or T-cell origin; however, the proportion of T-ENKTLs and whether they are of αß or γδ type remains uncertain. To elucidate the cell of origin and detailed phenotype of ENKTL and assess any clinicopathologic associations, 67 cases of ENKTL from Thailand were investigated, together with 5 γδ enteropathy-associated T-cell lymphomas (EATLs) for comparison. In all, 70% of the ENKTL were T-cell receptor (TCR) ß,γ and, in cases tested, δ negative (presumptive NK origin); 5% were TCR γδ, 3% were TCR αß, 1% were TCR αß/γδ, and 21% were indeterminate. Out of 17 presumptive NK-ENKTLs tested, 3 had clonal TCR rearrangements. All cases were EBV and TIA-1; >85% were positive for CD3, CD2, granzyme B, pSTAT3, and Lsk/MATK; and all were CD16. Presumptive NK-ENKTLs had significantly more frequent CD56 (83% vs. 33%) and CXCL13 (59% vs. 0%) but less frequent PD-1 (0% vs. 40%) compared with T-ENKTLs. Of the NK-ENKTLs, 38% were Oct-2 compared with 0% of T-ENKTLs, and 54% were IRF4/MUM1 compared with 20% of T-ENKTLs. Only αß T-ENKTLs were CD5. Intestinal ENKTLs were EBV and had significantly more frequent CD30, pSTAT3, and IRF4/MUM1 expression but less frequent CD16 compared with γδ EATL. Significant adverse prognostic indicators included a primary non-upper aerodigestive tract site, high stage, bone marrow involvement, International Prognostic Index ≥2, lack of radiotherapy, Ki67 >40%, and CD25 expression. The upper aerodigestive tract ENKTLs of T-cell origin compared with those of presumptive NK origin showed a trend for better survival. Thus, at least 11% of evaluable ENKTLs are of T-cell origin. Although T-ENKTLs have phenotypic and some possible clinical differences, they share many similarities with ENKTLs that lack TCR expression and are distinct from intestinal γδ EATL.

Cutaneous involvement by colonic extranodal NK/T-cell lymphoma mimicking mycosis fungoides: a case report*.

We report a 51-year-old woman with cutaneous involvement by extranodal NK/T-cell lymphoma (TCL) of the colon that microscopically mimicked mycosis fungoides (MF). She had a history of fever of unknown origin for 2 months and then developed multiple erythematous papules on her trunk and extremities. A skin biopsy revealed superficial infiltration by atypical small to medium-sized lymphocytes with epidermotropism and Pautrier collections. Immunohistochemical studies showed expression of CD3 and TIA-1 with lack of expression (double negative) of CD4 and CD8. Initially, we reported the diagnosis as MF, cytotoxic variant. Thereafter, computerized tomography scan incidentally identified a colonic mass. A colonic biopsy revealed infiltration of atypical lymphoid cells with the same morphology and immunophenotype as those found in the skin. Additionally, CD56 and Epstein-Barr virus-encoded RNA in situ hybridization in both skin and colonic biopsies were diffusely positive. Thus, extranodal NK/TCL was diagnosed. Delta T-cell receptor (TCR) gene rearrangement was documented in the skin biopsy by polyacrylamide gel electrophoresis and fluorescence capillary gel electrophoresis methods. There was no TCR gene rearrangement detected in the colonic biopsy. Unfortunately, the patient died within 2 months of diagnosis.

Aberrant antigenic expression in extranodal NK/T-cell lymphoma: a multi-parameter study from Thailand.

BACKGROUND: Extranodal NK/T-cell lymphoma, nasal type (ENKTL) is not common worldwide, but it is the most common T- and NK-cell lymphomas in many Asian countries. Immunophenotypic profiles were studied based on limited series. The authors, therefore, studied on ENKTL according to characterize immunophenotypic profiles as well as the distribution of EBV subtype and LMP-1 gene deletion. METHODS: By using tissue microarray (TMA), immunohistochemical study and EBV encoded RNA (EBER) in situ hybridization were performed. T-cell receptor (TCR) gene rearrangement, EBV subtyping, and LMP-1 gene deletion were studied on the available cases. RESULTS: There were 22 cases eligible for TMA. ENKTL were positive for CD3 (91%), CD5 (9%), CD7 (32%), CD4 (14%), CD56 (82%), TIA-1 (100%), granzyme B (95%), perforin (86%), CD45 (83%), CD30 (75%), Oct2 (25%), and IRF4/MUM1 (33%). None of them was positive for ßF1, CD8, or CD57. TCR gene rearrangement was negative in all 18 tested cases. EBV was subtype A in all 15 tested cases, with 87% deleted LMP-1 gene. Cases lacking perforin expression demonstrated a significantly poorer survival outcome (p = 0.008). CONCLUSIONS: The present study demonstrated TIA-1 and EBER as the two most sensitive markers. There were a few CD3 and/or CD56 negative cases noted. Interestingly, losses of CD45 and/or CD7 were not uncommon while Oct2 and IRF4/MUM1 could be positive in a subset of cases. Based on the present study in conjunction with the literature review, determination of PCR-based TCR gene rearrangement analysis might not be a useful technique for making diagnosis of ENKTL.