Five-year analysis from phase 2 trial of "sandwich" chemoradiotherapy in newly diagnosed, stage IE to IIE, nasal type, extranodal natural killer/T-cell lymphoma.

The "sandwich" protocol, was first proposed by us and comprised of l-asparaginase, vincristine, and prednisone chemotherapy with radiotherapy, results in 2-year overall survival and progression-free survival rates that surpass traditional therapies for patients with newly diagnosed, stage IE-IIE, nasal type, extranodal natural killer/T-cell lymphoma. The results had been published by cancer. These patients were followed up over a median period of 67 months, for which updates and the results of prognostic factors analyses are presented. The 5-year overall survival and progress-free survival rates were both 64%. The highest rates of death occurred during the first 6 months, and between the second and third year after enrollment. The initial therapeutic response (odds ratio = 5.83; P = 0.001) and B symptoms (odds ratio = 6.13; P = 0.043) were significant prognostic factors for overall survival. However, the international prognostic index was not significant for progress-free survival and overall survival. There were no severe long-term side effects. These results indicate that the "sandwich" protocol may benefit the long-term survival of patients with newly diagnosed stage IE-IIE, nasal type, extranodal natural killer/T-cell lymphoma. However, additional studies with larger samples are required to confirm these results. This study is registered at www.Chictr.org (ChicTR-TNC-09000394).

Identification of immunophenotypic subtypes with different prognoses in extranodal natural killer/T-cell lymphoma, nasal type.

To analyze the differentiation characteristics of extranodal natural killer/T-cell lymphoma, nasal type, one nude mouse model, cell lines SNK6 and SNT8, and 16 fresh human samples were analyzed by flow cytometry immunophenotyping and immunohistochemistry staining; and 115 archived cases were used for phenotypic detection and prognostic analysis. We found that CD25 was expressed by most tumor cells in all samples, and CD56(+)CD25(+) cells were the predominant population in the mouse model, the 2 cell lines, and 10 of the 16 fresh tumor samples; in the other 6 fresh tumor samples, the predominant cell population was of the CD16(+)CD25(+) phenotype, and only a minor population showed the CD56(+)CD25(+) phenotype. The phenotype detected by immunohistochemistry staining generally was consistent with the phenotype found by flow cytometry immunophenotyping. According to the expression of CD56 and CD16, 115 cases could be classified into 3 phenotypic subtypes: CD56(-)CD16(-), CD56(+)CD16(-), and CD56(dim/-)CD16(+). Patients with tumors of the CD56(dim/-)CD16(+) phenotype had a poorer prognosis than patients with tumors of the other phenotypes. Differentiation of extranodal natural killer/T-cell lymphoma, nasal type apparently resembles the normal natural killer cell developmental pattern, and these tumors can be classified into 3 phenotypic subtypes of different aggressiveness. Expression of CD56(dim/-)CD16(+) implies a poorer prognosis.

[Effect of doxorubicin on TRAIL resistance and TRAIL receptor expression in lymphoma cell line SNK-6 cells].

OBJECTIVE: To investigate the effect of doxorubicin on TRAIL resistance and TRAIL receptor expression in lymphoma cell line SNK-6 cells. METHODS: SNK-6 cells treated with doxorubicin at different concentrations alone or in combination with tumor necrosis factor related apoptosis inducing ligand (TRAIL). Cell proliferation was evaluated by MTT assay. Apoptosis and the expression of TRAIL receptors were determined by flow cytometry. RESULTS: MTT assay showed that treatment with 100 and 1000 ng/ml doxorubicin for 24 h, the survival rates of SNK-6 cells were (80.9 ± 7.2)% and (53.7 ± 2.8)%, significantly higher than that by treatment combined with 500 ng/ml TRAIL (64.9 ± 1.1)% and (34.0 ± 3.9)%, respectively (P < 0.05). Flow cytometry showed that after treatment with 100 and 1000 ng/ml doxorubicin for 48 h, the survival rates of SNK-6 cells were (69.9 ± 6.1)% and (31.1 ± 1.9)%, while treated in combination with 500 ng/ml TRAIL, the cell survival rates were (37.5 ± 6.4)% and (15.0 ± 1.8)%, respectively. The early apoptosis rate was (14.8 ± 0.6)% and (30.8 ± 1.5)%, significantly lower than that [(28.7 ± 0.6)% and (46.6 ± 2.8)%] after treatment in combination with TRAIL (P < 0.05). The expressions of TRAIL receptors and decoy receptors were increased when SNK-6 cells were treated with 100 ng/ml doxorubicin for 24 hours. CONCLUSIONS: Doxorubicin can overcome to a certain extent the TRAIL resistance of SNK-6 cells and induce upregulation of TRAIL death receptors and decoy receptors on the surface of SNK-6 cells. However, a higher dose is needed.

[Diffuse large B-cell lymphoma of testis: a clinicopathologic and immunophenotypic study of 58 cases].

OBJECTIVE: To investigate the clinicopathologic features, immunophenotype, diagnosis and differential diagnosis, and prognostic factors of testicular diffuse large B-cell lymphoma (DLBCL). METHODS: The clinical and pathologic profiles of 58 cases of testicular DLBCL were investigated.Immunohistochemical stainings and EBER1/2 in situ hybridization were performed on formalin fixed tissues. RESULTS: The average age of the patients was 62.1 years, and the median age was 65 years. The course of disease was short in most of the cases. Clinical stages at diagnosis were mainly stage I or II (87.9%, 51/58). Forty eight patients (82.8%) had unilateral testis involvement. Inguinal lymphadenopathy was observed in 12 (20.7%) patients and the other organs were seldom involved. Morphologically, centroblast-like neoplastic cells infiltrated interstitial tissue of testis diffusely and invaded into seminiferous tubules. Tunica albuginea and vessels were involved in 14 (24.1%) and 10 (17.2%) patients, respectively. Immunophenotype analysis showed predominant non-GCB type of DLBCL (48/58, 82.8%) by Hans classification. No EBV infection was detected. Follow-up data were available in 48 (82.8%) patients. Twenty eight patients (58.3%) died of the disease. One-year, 3-year, and 5-year overall survivals were 55.7%, 31.6% and 27.6%, respectively. Age (older than 60 years), B-symptoms, high serum level of LDH, advanced Ann Arbor stage as well as lack of combination of therapy were associated with a poor prognosis. CONCLUSIONS: This large series of testicular DLBCL mainly present with local disease at diagnosis. Most cases show non-GCB immunophenotype. Despite early clinical stage at presentation, the prognosis is poor. Combined chemotherapy postoperation may prolong survival of the patients.

[CD16 expression is an independent prognostic factor for extranodal NK/T cell lymphoma of nasal type].

OBJECTIVE: To analyze the clinicopathologic features of extranodal NK/T cell lymphoma, nasal type (ENKTCL-N), to explore the expression of NK cell-associated receptors in ENKTCL-N and the relationship with prognosis, and to establish a prognostic model. METHODS: One hundred and twenty-six cases of ENKTCL-N were selected from the files of the Department of Pathology, West China Hospital of Sichuan University. The relevant clinical and follow-up data were collected, and the histopathology was reviewed. All specimens were stained immunohistochemically for CD16, ICAM-1 and LFA-1. RT-PCR was used to detect the expression of CD94, NKG2 and KIR. The relationship between the prognosis of ENKTCL-N, clinical features, histopathological characteristics and expression of these markers were also analyzed. RESULTS: ENKTCL-N mainly occurred in middle-age and young patients (median age, 41 years). The male to female ratio was 3.2:1. Sites more commonly involved were the nose and upper aerodigestive tract whereas those for the non-nasal type were the skin and gut. Only six cases involved two or more extranodal sites. Most (86.5%, 109/126) of the patients were in clinical stages I/II. The tumors showed predominately medium-sized tumor cells and large-sized tumor cells accounted for only 9.5% (12/126). Coagulative necrosis was present in all cases. The expression rates of CD56, CD16, CD94, LFA-1 and ICAM-1 were 82.6% (95/115), 15.1% (19/126), 55.4% (41/74), 40.5% (51/126) and 0, respectively. The expression rate of NKG2 receptor was 90.5% (67/74) overall. NKG2 receptor expression was independent of CD94. The overall expression rate of KIR receptor was 33.8% (25/74) and KIR receptor restriction was not detected in 20.8% (5/24) of the cases. Follow-up data was available in all patients, with median and average survival time being 15 months and 20.2 months, respectively. Survival analysis showed that prognostic factors included the gender, age, disease type, extranodal involvement, stage, the expression of CD16, LFA-1 and CD94. Cox's proportional hazard regression analysis revealed four factors, age, involved site, stage and CD16 expression, were independent prognostic factors. CONCLUSIONS: The age, disease type, stage and CD16 expression are independent prognostic factors. Establishment of a prognostic model based on the above four factors can be more accurate in the prognostication of ENKTCL-N. The differences in the clinical features, prognosis, and expression of NK cell-associated receptors are obvious between nasal NK-cell lymphoma and non-nasal NK-cell lymphoma.

Hydroa vacciniforme-like lymphoma of an adult: a case report with review of the literature.

Hydroa vacciniforme-like lymphoma (HVL) is a rare type of Epstein-Barr virus (EBV)-positive lymphoma of cytotoxic T-cell or natural killer cell origin that mainly affect children, characterized by a vesicopapular skin eruption that clinically resemble hydroa vacciniforme (HV). In current study, we report an adult patient with the tumor. The patient presented similar morphologic, immunophenotypic and genotypic changes of the disease with that occurred in children, whereas clinically, he showed a prolonged clinical course without hepatosplenomegaly or generalized lymphadenopathy. Whether there are some differences in biologic behavior between children and adults still remains unknown and it is necessary to collect more data to observe and to investigate in the future. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7644172219178472.

Aggressive natural killer-cell leukemia with jaundice and spontaneous splenic rupture: a case report and review of the literature.

Aggressive natural killer cell leukemia/lymphoma (ANKL) is a rare aggressive form of NK-cell neoplasm. We report an uncommon case of 36-year-old male who showed jaundice and spontaneous splenic rupture. The diagnosis was established by the biopsy of liver and spleen. The monomorphous medium-size neoplastic cells infiltrated into portal areas and sinus of liver as well as the cords and sinus of the spleen. Necrosis, mitotic figures and significant apoptosis could be seen easily. These neoplastic cells demonstrated a typical immunophenotype of CD3ε+, CD56+, CD16+, Granzyme B+, TIA-1+. T-cell receptor γ (TCR-γ) gene rearrangement analysis showed germline configuration and the result of in situ hybridization for Epstein-Barr virus-encoded RNA (EBER-ISH) was positive. The patient has undergone an aggressive clinical course and died of multi-organ function failure 14 days later after admission. To the best of our knowledge, this is the first case of ANKL with spontaneous splenic rupture, and we should pay more attention to recognize it. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2048154883890867.

Invasion-associated genes identified by gene expression profiling in extranodal natural killer/T-cell lymphoma, nasal type.

To identify invasion-associated genes in extranodal natural killer (NK)/T-cell lymphoma, we performed microarray analysis on seven tumor samples and two control pools (composed of normal NK cells and T cells, tonsil and spleen) using Affymetrix GeneChip. Compared with all control pools, 59 uniquely expressed genes were discovered in the tumor samples. Overexpressed genes related to proteolysis, cell motility and chemotaxis, including CTSL, uPAR, TIMP-1, CXCL9, CXCL11 and DEFB1, were identified. Comparing the gene expression profiles of five upper aerodigestive tract (UAT) cases with two non-UAT cases, we found some overexpressed genes in non-UAT cases related to proteolysis and cell adhesion function, including matrix metalloproteinase 9 (MMP-9). Immunohistochemistry detection was performed on 34 paraffin sections to evaluate the expression of selected genes. A correlation of urokinase-type plasminogen activator receptor (uPAR) expression with MMP-9 expression was revealed. Analysis of prognosis demonstrated that expressions of MMP-2 and MMP-9 were closely correlated with a poor prognosis. These invasion-associated genes may become targets for diagnostic and therapeutic procedures.

Sporadic Burkitt lymphomas of children and adolescents in Chinese: a clinicopathological study of 43 cases.

BACKGROUND: To investigate the clinical and pathologic features as well as the MYC translocations of childhood Burkitt lymphoma (BL) from China. METHODS: Fourty-three cases of childhood BL were retrospectively investigated in morphology, immunophenotype, genotype, treatments and survival analysis. RESULTS: Clinically, there was a marked male predominance in sex distribution (M: F=9.75:1); abdomen was the most frequent extranodal sites of involvement (46.5%), followed by jaws and facial bones (16.3%). Two third of the patients were in stageI ~ II. Morphologically, 69.76% of the cases showed classical histologic features, while 30.24% of them showed greater nuclear pleomorphism in size and shape. Five cases (11.6%) were positive for EBER1/2. Thirty-one of the 40 cases (77.5%) had the aberration of IGH/MYC translocation while 7 (17.5%) had non-IGH/MYC translocation. Thirty patients (69.7%) received operation and/or chemotherapy while 13 patients (30.3%) received no treatment. Twenty-seven patients (62.8%) died of the tumor, 16 alive, with the average survival time 4.9 and 48.7 months respectively. High IPI, advanced clinical stage, increased serum level of LDH and no chemotherapy received as well as tumor size≥10 cm were related to the lower survival rates of the tumor. CONCLUSIONS: Several differences were showed in this group of BL, including a much higher ratio of male patients, more cases in stageII, clinically inconsistent treatment and a very poor outcome. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here http://www.diagnosticpathology.diagnomx.eu/vs/1552295877710135.

[Langerhans cell histiocytosis: a clinicopathologic and immunohistochemical analysis of 258 cases].

OBJECTIVES: To observe the clinicopathologic features of Langerhans cell histiocytosis (LCH), and to evaluate the values of langerin, CD1a and S-100 protein expression in diagnosis of the tumor. METHODS: Total 258 cases of Langerhans cell histiocytosis in the past 18 years (from 1992 to 2008) were collected, morphologic review and immunohistochemical staining were performed. RESULTS: In all 258 cases, the ages of patients older than 16 years or younger than 2 years were 126 (48.8%) and 37 (14.3%), respectively, in the remaining 95 (36.8%) of the cases, the age of the patients ranged from 2 to 16 years. For all of 258 cases, there were 364 diseased sites. Bony lesions accounted for 77.2% (281 cases), especially the skull (112 cases, 39.9%), followed by lymph node (25 cases, 6.9%) and skin (14 cases, 3.8%). Clinically, unisystem or unifocal disease was predominant (201 cases, 77.9%), followed by unisystem and multifocal disease (21 cases, 8.1%), multi-system disease (26 cases, 10.1%), isolated pulmonary LCH (2 cases, 0.8%), and unclassified (8 cases, 3.1%). Histologically, variable number of Langerhans cells was present in 265 samples of 258 cases. Multinucleated giant cells were found in 166 (62.6%) of the samples. Eosinophils were the major infiltrating non-neoplastic cells, and eosinophilic abscess was seen in 57 cases (21.5%). Coagulative necrosis and dead bone were detected in 29 (10.9%) and 124 (46.8%) of the cases, respectively. Immunohistochemically, the expression of S-100 protein, CD1a and langerin was 99.1% (209/211), 100% (206/206) and 98.5% (193/196), respectively, and the sensitivity of them had no statistical difference. CONCLUSIONS: In this group of LCH cases, the ratio of adult patients is high, but the proportion of multi-organ lesion is low. No significant difference of the sensitivity is found among langerin, CD1a and S-100 expression in diagnosis of LCH.

Extranodal nasal type natural killer/T-cell lymphoma of testis: report of seven cases with review of literature.

Seven cases of testicular extranodal natural killer (NK)/T-cell lymphoma, nasal type, are reported, with a literature review. Two patients had a testicular lesion as the initial presentation, four had a history of nasal NK/T-cell lymphoma and the remaining patient had concomitant involvement of an adrenal gland. All patients underwent orchiectomy followed by chemotherapy (CT) and/or radiotherapy (RT). Follow-up data showed that two patients with non-primary tumors died of disease within 6 and 11 months, respectively. Histologically, the tumor had a diffuse growth pattern largely replacing the interstitial tissues. Neoplastic cells showed prominent angiocentric and angioinvasive features with focal coagulative necrosis and apoptotic bodies. Immunohistochemically, all cases were positive for cytoplasmic CD3ε and CD56. Epstein-Barr virus infection was demonstrated in all cases. Testicular NK/T-cell lymphoma, whether primary or secondary, was generally very aggressive with a poor outcome despite multimodality therapy. Novel molecular therapeutic targets and more effective treatments are needed, especially for disseminated or recurrent cases.

Extraosseous (extramedullary) plasmacytomas: a clinicopathologic and immunophenotypic study of 32 Chinese cases.

BACKGROUND: Extraosseous plasmacytoma, so called extramedullary plasmacytoma (EMP) is relatively rare in China. The aim was investigate the clinicopathologic features of EMP and the role of Immunophenotype and genotype detection in diagnosis of EMP. METHODS: Thirty-two cases of EMP were investigated retrospectively by histopathology, immunophenotype, genotype and survival analysis. RESULTS: Clinically, the mean age of the patients was 53.4. Most of the patients received no treatment after the diagnosis was established, and the prognosis was relatively poor. Histologically, in 40% of the cases, the neoplastic cells were grade II or III. The neoplastic cells expressed one or more PC associated antigens. The immunophenotype of EMP and inflammation of sinonasal regions with numerous PC infiltrations were compared and showed some difference in expression of CD45, CD27, CD44v6 and Bcl-2 as well. Ig light chain restriction was detected in 87.5% of the cases. CONCLUSIONS: we described 32 Chinese cases of EMP, compare with that reported in the literature, some differences are presented, including higher percentage of grade II and III cases, clinically inconsistent treatment and management as well as poor outcome of the disease.

Subtype distribution of lymphomas in Southwest China: analysis of 6,382 cases using WHO classification in a single institution.

BACKGROUND: The subtype distribution of lymphoid neoplasms in Southwest China was analyzed according to WHO classifications. This study aims to analyze subtype distribution of lymphomas in southwest China. METHODS: Lymphoid neoplasms diagnosed within 9 years in a single institution in Southwest China were analyzed according to the WHO classification. RESULTS: From January 2000 to December 2008, a total number of 6,382 patients with lymphoma were established, of which mature B-cell neoplasms accounted for 56%, mature T- and NK-cell neoplasms occupied 26%, and precursor lymphoid neoplasms and Hodgkin lymphomas were 5% and 13%, respectively. Mixed cellularity (76%) was the major subtype of classical Hodgkin lymphoma; and the bimodal age distribution was not observed. The top six subtypes of non-Hodgkin lymphoma were as follows: diffuse large B-cell lymphoma, extranodal NK/T-cell lymphoma, nasal type, extranodal marginal zone lymphoma of mucosa associated lymphoid tissue, follicular lymphoma, precursor lymphoid neoplasms, and chronic lymphocytic leukemia/small lymphocytic lymphoma. Extranodal lymphomas comprised about half of all cases, and most frequently involved Waldeyer's ring, gastrointestinal tract, sinonasal region and skin. CONCLUSIONS: The lymphoid neoplasms of Southwest China displayed some epidemiologic features similar to those reported in literature from western and Asian countries, as well as other regions of China, whereas some subtypes showed distinct features. The high frequency of mature T/NK cell neoplasms and extranodal lymphomas, especially for extranodal NK/T-cell lymphoma, nasal type, is the most outstanding characteristic of this series.

Hepatosplenic T-cell lymphoma: clinicopathologic, immunophenotypic, and molecular characterization of 17 Chinese cases.

Hepatosplenic T-cell lymphoma is a highly aggressive tumor with a poor outcome. About 210 cases were identified through PubMed, of which fewer than 20 originated in Asia. We reviewed 17 Chinese cases of hepatosplenic T-cell lymphoma, including an unusual one with cutaneous pink papules, for clinicopathologic, immunophenotypic, and genotypic features; Epstein-Barr virus status; treatment; and outcome. The median age of the patients was 23 years. All patients had splenomegaly, and 88.2% of them had hepatomegaly as well. Bone marrow involvement was present in 53.3%. Eleven patients underwent splenectomy for diagnosis and treatment. Twelve specimens were collected by image-guided liver core biopsy or wedge resection. Histologically, the homogeneous small- to medium-size neoplastic lymphoid cells infiltrated the sinuses or sinusoids of the spleen, bone marrow, and liver. Diagnosis was based on image-guided core-needle biopsy of the liver alone in 41.2% of the cases. Immunohistochemically, 15 of the lesions were hepatosplenic γδ T-cell lymphoma, and the remaining 2 were hepatosplenic αß T-cell lymphoma. Epstein-Barr virus was detected in both cases of hepatosplenic αß T-cell lymphoma and one case of hepatosplenic γδ T-cell lymphoma. Most of the patients received cyclophosphamide, doxorubicin, vincristine, and prednisone therapy or regimens similar to it. Follow-up data were available in 70.6% of the patients; half of them died of the tumor, and the median survival time was 6 months. The frequency of bone marrow involvement was lower than that reported in the literature. Image-guided core-needle biopsy of the liver is recommended for diagnosis.

[Solitary plasmacytoma of bone: a clinicopathologic, immunohistochemical and immunoglobulin gene rearrangement study].

OBJECTIVE: To investigate clinicopathologic features of solitary plasmacytoma of bone (SPB) and the role of immuno-phenotype and immunoglobulin gene rearrangement detection in the diagnosis and differential diagnosis of SPB. METHODS: A total of 21 cases of SPB were selected during a period from 1990 to 2008. A retrospective clinicopathologic study and immunohistochemistry (EnVision or EliVision methods) of 17 antigens were performed. In addition, universal IgH (FR3A/LJH/VLJH) primers and BIOMED-2 PCR multiplex tubes were used for IgK and IgL rearrangement analysis. RESULTS: The age of patients ranged from 36 to 72 years with a media of 50 years. Axial skeleton was the most common site of involvement, accounting for 66.7% of the cases (14 of 21), followed by the extremities of 33.3% (7 cases). Low serum level of M-components was found in 5 cases, including two of IgG type (21.4 g/L) and three of IgA type. Clinical manifestations were closely related to the anatomic sites involved, such as pain due to bone destruction, symptoms and signs caused by compression of spinal cord or nerve root, and pathological fracture. All cases presented as a solitary osteolytic lesion. According to the histological grading criteria, grade I tumor was seen in 12 of 21 cases (57.1%). The remaining were grade II (5 cases, 23.8%) and grade III (4 cases, 19.0%). Immunohistochemically, the neoplastic cells expressed two or more plasma cell antigens, including CD138, CD38 and PC, but no CD19 and CD20. CD79a expression detected in 23.8%(5/21) of the cases. Expression of CD56, CD27 and CD44v6 were 57.1% (12/21), 15.0% (3/20) and 23.8% (5/21), respectively. Follow-up data were available in 12 of the 21 patients (57.1%). Five patients were alive and 7 died. Three patients developed multiple myeloma (MM) and died of the tumor. CONCLUSIONS: SPB is a rare tumor with bone pain as the most common presenting symptom due to bone destruction. The diagnosis of EMP can only be established after exclusion of an extramedullay invasion by MM. Immunophenotype and IgH gene rearrangement analysis play important roles in the diagnosis of SPB.

[Small cell variant of peripheral T-cell lymphoma, not otherwise specified: a clinicopathologic and immunophenotypic analysis].

OBJECTIVE: To study the clinicopathologic features and differential diagnosis of small cell variant of peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS). METHODS: The clinicopathologic features of 5 cases of small cell variant of PTCL, NOS were retrospectively reviewed, with immunohistochemical study, T-cell receptor (TCR) gene rearrangement analysis and evaluation for Epstein-Barr virus (EBV) status. RESULTS: All the 5 patients were males. The mean age was 52.6 years. The median duration before diagnosis was 1 month. Clinically, 3 patients presented in stage IV and 2 in stage III. Four of them had generalized lymphadenopathy and splenomegaly. Hepatomegaly and massive effusion were found in 1 and 2 cases, respectively. Marrow involvement was detected in 3 of the 4 patients with bone marrow biopsy performed and one of them also accompanied by lymphocytosis. Histologically, the involved lymph nodes showed partial or complete effacement of nodal architecture and replacement by a monomorphous population of small lymphoid cells. Scanty large lymphoid cells were also identified in 4 cases. Increase in number of blood vessels was noticed in two of them as well. Immunohistochemically, the lymphoma cells in all cases expressed two or more of the T-cell markers and CD43. The staining for CD20, TdT, CD56 and granzyme B was negative. CD99 expression was noted in 3 of the 4 cases. The Ki-67 index ranged from 5% to 15%. Clonal TCRgamma gene rearrangement was detected in the 4 cases studied and one of them also showed TCRbeta gene rearrangement. In-situ hybridization for EBV-encoded RNA was negative in the 4 cases studied. Follow up information was available in 3 of the 5 cases. All of the 3 patients died of the disease, with an average survival of 21.7 months. CONCLUSION: Small cell variant of PTCL, NOS represents a rare disease entity which often presents in advanced tumor stage and carries a poor prognosis.