Natural killer cell malignancy associated with Epstein-Barr virus and hemophagocytic syndrome.

Natural killer cell malignancy is a rare and aggressive lymphoid neoplasm encompassing extra-nodal NK/T-cell lymphoma, nasal-type (ENKLN) and aggressive NK-cell lymphoma/leukemia (ANKL). A case of cutaneous ENKLN and a case of ANKL in Thai patients are reported Both patients developed hemophagocytic syndrome and shortly succumbed to death. The cells in cutaneous ENKLN are small to medium in size with minimal cytoplasm, round nuclei, irregular nuclear membrane, andfine chromatin with inconspicuous nucleoli. While that of ANKL are medium to large-sized mononuclear cells with moderate cytoplasm. Their nuclei are elongated to embryo-like with irregularly thickened nuclear membrane, fine chromatin, and small to occasional prominent nucleolus. Ancillary techniques studied on paraffin embedded tissues of both cases demonstrated that the neoplastic cells exhibit cytoplasmic CD3+, CD56+ and cytotoxic granules + by immunohistochemistry, absence of T cell receptor gene rearrangement by PCR, and presence of Epstein-Barr virus mRNA (EBER) transcripts by in situ hybridization. The authors reviewed the literature on natural killer cell neoplasm and compared the clinical characteristics, natural history, and association of Epstein-Barr virus infection with hemophagocytic syndrome.

Overexpression of c-Myc in primary central nervous system lymphoma of Thais.

BACKGROUND: c-Myc protooncogenes have been implicated in the tumourigenesis of extracerebral lymphomas, however only afew studies on this oncogenic molecule have been available for primary central nervous system lymphoma (PCNSL). OBJECTIVE: To determine the prevalence ofprotein overexpression and gene amplification of c-Myc in PCNSL and to correlate with histological and immunophenotypic subtypes of malignant lymphoma according to WHO classification of tumors of haematopoietic and lymphoid tissue 2001. SETTING: King Chulalongkorn Memorial Hospital, Thailand. DESIGN: Descriptive study. MATERIAL: 25 Thai patients presented between 2001 and 2005. METHOD: The overexpression and amplification of c-Myc in malignant lymphoma were studied by means of immunohistochemistry and chromogenic in situ hybridization (CISH), respectively, in formalin-fixed, paraffin-embedded specimens. The histomorphology and immunohistochemistry were used to subclassify PCNSLs according to WHO classification 2001. RESULTS: Fourteen males and eleven females were recruited. They were between the ages of 21 and 86 years with the mean of 53 years. Eight had documented human immune deficiency virus (HIV) infection. Four of 17 immunocompetent cases overexpressed c-Myc protein without c-Myc gene amplification. No immunocompromised cases showed overexpression of c-Myc protein. All PCNSLs were classified as diffuse large B-cell lymphoma. CONCLUSION: In PCNSL, c-Myc overexpression is notfound immunocompromised (HIV-infected) patients and is found in 23.5% of the immunocompetent individuals without c-Myc gene amplification. All PCNSLs are diffuse large B-cell lymphoma according to WHO classification 2001.

RET proto-oncogene expression of papillary thyroid carcinomas in Thai patients.

BACKGROUND: Ret proto-oncogene activation has been found in papillary thyroid carcinoma with different frequencies according to geographic location. The rate of expression ranges from 0-100 percent in the literature. This gene expression has also been studied in many Asian countries but it has never been studied in Thailand. OBJECTIVE: To study the frequency of the RET expression and their roles in predicting prognosis of papillary thyroid carcinoma among Thai patients treated at King Chulalongkorn Memorial Hospital, Bangkok, Thailand. MATERIAL AND METHOD: One hundred and one cases of papillary carcinomas were studied with immunohistochemistry for RET antibodies. All slides with routine staining were reviewed to classify cell variants and record other prognostic parameters such as size, multicentricity, extrathyroid invasion. The clinical data such as age and sex were also included for analyses. RESULTS: Forty-seven of the total 101 cases (46.5%) showed positive RET protein staining. The mean age among patients with RET negative neoplasms was 43.9 years compared with 39.8 years in RET positive group (p = 0.16). The average size of the tumors without RET expression was 2.5 cm, slightly larger than the RET positive tumors (2.1 cm)(p = 0.26). Extrathyroid invasion of the RET-positive tumors was found to be 33.2 percent while the RET negative neoplasms had 38.8 percent of this feature (p = 1). According to AMES score, the RET positive cases had only 11 percent of high-risk tumors, whereas the RET negative group comprised 23.1 percent of high-risk malignancies (p = 0.20). There was no significant difference in RET expression among cell variants (p = 1). CONCLUSION: The study of 101 papillary thyroid carcinomas at the King Chulalongkorn Memorial Hospital disclosed high frequency of RET expression (46.5%) and this is the only data among Thai patients that has ever been documented in the literature. Although, the gene expression in the tumor tends to be associated with good prognostic features but it was not distinct enough to be statistically significant.

Polymerase chain reaction for detection of Mycobacterium tuberculosis in papanicolaou-stained fine needle aspirated smears for diagnosis of cervical tuberculous lymphadenitis.

A polymerase chain reaction (PCR) protocol for detecting IS6110 repetitive insertion sequence of Mycobacterium tuberculosis (MTB) was tested on archival Papanicolaou (Pap)-stained fine needle aspirated (FNA) smears from 24 patients with cervical tuberculous lymphadenopathy and 30 negative controls. The protocol involved protease digestion or phenolchloroform extraction, and simple or nested PCR, with PCR amplification of human beta-globin gene for internal control of DNA quality. Sensitivity of 50% and specificity of 100% were obtained. Sensitivity in smears showing necrosis without granuloma was 70% (7/10), whereas it was 36% (5/14) in smears with presence of granuloma. On the other hand, sensitivity of 18% (4/22) was obtained using FNA acid-fast stain, 25% (1/4) for acid-fast stain in histological section, 50% (2/4) for culture, and 100% (8/8) for PCR of fresh specimens. PCR for MTB detection in Papanicolaou-stained slides is a practical and valuable method when no fresh specimen but only Pap-stained smear is available.

Necrotizing non-granulomatous lymphadenitis: a clinicopathologic study of 40 Thai patients.

The purpose of this study was to describe the clinicopathological features of 40 cases of necrotizing non-granulomatous lymphadenitis in Thai patients. The clinical features, histomorphology and special stains were evaluated in 40 Thai patients from the pathology records of King Chulalongkorn Memorial Hospital from January 2001 to December 2003 in those diagnosed as having necrotizing non-granulomatous lymphadenitis. Of the 40 patients, 17 cases (42.5%) had Kikuchi-Fujimoto disease (KFD), 8 cases (20%) had tuberculosis (TB) lymphadenitis and 1 case (2.5%) had systemic lupus erythematosus (SLE) with associated lymphadenitis. Fourteen cases (35%) did not have a specific diagnosis due to a lack of follow-up data. KFD most commonly occurs in young women, and is characterized by the presence of coagulative necrosis and karyorrhexis often centered in the paracortex, an absence of neutrophils and plasma cells, proliferation of various cells composed of lymphocytes, histiocytes, immunoblasts and plasmacytoid monocytes and the absence of a granuloma. Tuberculous lymphadenitis usually occurs in women with a mean age of 34.25 years. The lymph nodes reveal extensive coagulative necrosis involving the cortex, paracortex and medulla, proliferation of mixed inflammatory cells, including neutrophils, lymphocytes and plasma cells in the necrotic area and the presence of proliferating histiocytes at the periphery of the necrotic area. The lymph nodes of SLE-associated lymphadenitis reveal large numbers of plasma cells and hematoxylin bodies. We suggest that necrotizing non-granulomatous lymphadenitis is not specific for any disease, but rather a common histologic change found in diseases, such as TB, SLE, and KFD. Further investigation to obtain a definite diagnosis should be done for appropriate treatment.

Extranodal malignant lymphoma of the upper aerodigestive tract: prevalence of Epstien-Barr virus (EBV) infection in King Chulalongkorn Memorial Hospital.

BACKGROUND: High frequency of Epstein-Barr virus (EBV) in the normal mucosa of the upper aerodigestive tract suggests that it may serve as a reservoir for the virus. Malignant lymphomas arising in this site may be associated with EBV. OBJECTIVES: To determine the prevalence of EBV infection in extranodal malignant lymphomas of the upper aerodigestive tract. SETTING: King Chulalongkorn Memorial Hospital, Thailand. DESIGN: Descriptive study. PATIENTS: 42 Thai patients who presented between 1998 and 2003. MATERIAL AND METHOD: The expression of EBV mRNAs (EBERs) of malignant lymphoma was studied by means of in situ hybridization in formalin-fixed, paraffin-embedded specimens. RESULTS: The recruited subjects were 26 males and 16 females, and their age ranged from 3 to 85 years with the mean of 51.43 years, in 4 of them human immune deficiency virus (HIV) infection was documented. Ten of 42 cases (23.81%) expressed EBER transcripts and were extranodal NK/T-cell lymphomas, nasal type (7 cases), plasmablastic lymphomas (2 cases) and diffuse large B-cell lymphoma (1 case). Three of 4 cases (75%) of known HIV-seropositive cases were EBV-positive (2 plasmablastic lymphomas and 1 diffuse large B-cell lymphoma). CONCLUSION: In the upper aerodigestive tract, EBV was present in some but not all malignant lymphoma. It was associated with extranodal NK/T-cell lymphoma, nasal type and B-cell lymphoma arising in HIV-infected patients, but it was not found in B-cell lymphoma arising in immunocompetent patients.

Parvovirus b19 infection in HIV patient with pure red cell aplasia.

Anemia in HIV-infected patients is a common clinical manifestation. We report on a 31-year-old Thai male, who had been HIV positive for 6 years, did not harbor any opportunistic infection, and had been receiving Highly Active Anti Retroviral Therapy (HAART) for one month, and who developed severe anemia. Investigation revealed pure red cell aplasia, suspected secondary to parvovirus B19 infection. This diagnosis was confirmed by the detection of parvovirus B19 DNA in his serum. He received blood transfusions for supportive treatment and continued on HAART to improve his immune status and to resolve the anemia. This case suggests that parvovirus B19 infection should be considered as a possible cause of anemia in HIV-infected individuals.

Extranodal malignant lymphoma of the upperaerodigestive tract in King Chulalongkorn Memorial Hospital according to WHO classification.

BACKGROUND: The Working Formulation commonly used to classify NHL in Thailand has been recognized as imperfect for primary extranodal lymphoma, especially in head and neck regions. OBJECTIVE: To study the clinicopathological and immunohistochemical features of extranodal malignant lymphoma of the upper aerodigestive tract according to WHO classification. SETTING: King Chulalongkorn Memorial Hospital. DESIGN: Descriptive study. PATIENTS: 77 Thai patients who presented between 1998 and 2003. METHODS: Routine histology was performed and stained with H&E and immunohistochemistry, and clinical characteristics were recorded. RESULTS: The patients included 42 males and 35 females, with an average age of 53.87 years. Tumor sites were as follows: Waldeyer ring (n = 42, 54.55%), sinonasal areas (n = 19, 24.67%), oral cavity (n = 9, 11.69%), hypopharynx (n = 4, 5.19%), and larynx (n = 3, 3.90%). Immunohistochemically, 57 tumors (74.02%) were of B-cell phenotype and 19 tumors (24.68%) were of T-cell phenotype. According to the WHO classification, 45 cases (58.43%) were large B-cell, 3 (3.90%) were Burkitt, 3 (3.90%) were marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT), 4 (5.19%) were follicular lymphoma, 1 (1.30%) was precursor B-lymphoblastic lymphoma, and 1 (1.30%) were mantle cell lymphoma. Among the T-cell lymphomas, 9 (11.69%) were of peripheral T-cell lymphoma, unspecified, 9 (11.69%) were extranodal NK/T cell lymphoma, nasal type, and 1 (1.30%) were anaplastic large-cell lymphomas. In nasal cavity, 8 tumors (42.11%) were extranodal NK/T-cell lymphoma, nasal type, 5 (26.32%) were diffuse large B-cell lymphoma, 4 (21.05%) were peripheral T-cell lymphoma, unclassified, and 1 (5.26%) was Burkitt lymphoma. CONCLUSION: Our data correspond with series from Japan, Hong Kong, and Korea, but there is a significant difference from Western population in T-cell lymphomas of sinonasal area especially extranodal NK/T cell lymphoma of nasal type and peripheral T-cell lymphoma, unspecified which had a higher frequency in Thailand, Japan, Hong Kong, and Korea.