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Although it is fairly well accepted that pulmonary tuberculosis is a major risk factor of lung cancer, the exact molecular mechanisms involved in its tumorigenesis are unclear. For this purpose, we have examined the relationship between Mycobacterium tuberculosis (M-TB) infection and FHIT gene alteration in lung cancer. Tumors with M-TB infection had a slightly higher abnormal FHIT protein expression compared with tumors without M-TB infection, although not statistically significant (Fisher's exact test, P=0.248). LOH affecting at least one locus of the FHIT gene was significantly more frequent in lung cancer patients with M-TB infection than in patients without M-TB infection whether assessment by univariate testing methods or logistic regression modeling analysis (Fisher's exact test P=0.025, logistic regression analysis P=0.012). These results indicate that M-TB infection is associated with FHIT gene LOH in lung cancer.

To study the clinicopathologic features of various types of mature T-cell and natural killer (NK)/T-cell lymphoma in Guangdong, China, with respect to the 2008 WHO classification of lymphoid neoplasms.Eleven hundred and thirty-seven (1137) cases of mature T-cell or NK/T-cell lymphoma diagnosed during the period from 2002 to 2006 in Guangzhou area were retrieved. The clinical data, histologic features and immunohistochemical findings were reviewed by a panel of experienced hematopathologists. Additional immunostaining was performed if indicated. The cases were re-classified according to the 2008 WHO classification of lymphoid neoplasms.Nine hundred and sixty-three (963) cases fulfilled the diagnostic criteria of mature T-cell or NK/T-cell lymphoma and accounted for 20.1% of all cases of lymphoma encountered during the same period (963/4801). A predominance of extranodal involvement was noted in 644 cases (66.9%), while 319 cases (33.1%) showed mainly nodal disease. The prevalence of various lymphoma subtypes was as follows: peripheral T-cell lymphoma, unspecified (PTCL, NOS) 293 cases (30.4%), extranodal NK/T-cell lymphoma, nasal type 281 cases (29.2%), anaplastic large cell lymphoma (ALCL) 198 cases (20.6%), and angioimmunoblastic T-cell lymphoma (AILT) 46 cases (4.8%). The male-to-female ratio was 1.99. The median age of the patients was 44 years, with the peak age of PTCL, NOS, extranodal NK/T-cell lymphoma, nasal type and AILT being 55 to 64 years, 25 to 54 years and 65 to 74 years, respectively. ALK-positive ALCL occurred more frequently in young age, while the ALK-negative ALCL cases occurred mainly in the elderly.Extranodal lesions predominate in mature T-cell and NK/T-cell lymphomas occurring in Guangzhou area. There is a male predominance and the overall incidence shows no increasing trend with age of the patient. The peak age of various subtypes however varies. The most common subtype was PTCL, NOS, followed by extranodal NK/T-cell lymphoma, nasal type, ALCL and AILT. The relatively frequent occurrence of extranodal NK/T-cell lymphoma, nasal type in Guangdong area is likely associated with the high incidence of Epstein-Barr virus infection there.

To study the origins and clonality of Hodgkin and Reed-Sternberg (H/RS) cells and their relations with the background lymphocytes in classical Hodgkin's lymphoma.IgH gene rearrangement was detected in paffin-embedded tissues from 33 patients with Hodgkin's lymphoma and a further analysis of the gene rearrangement was conducted in 6 of the positive cases identified after immunostaining of the sections with B-cell-specific activator protein (BSAP) followed by microdissection of the positivity labeled H/RS cells and background lymphocytes.IgH gene rearrangement was identified in 16 of the 33 cases. Microdissection of the lymphoma tissues was successfully performed in the 6 positive cases, and of the 19 tubes of H/RS cells obtained, 14 presented clonal bands of the rearrangement, and difference in cell numbers did not significantly influence the positive rate (P=0.290); in the 12 tubes of microdissected background lymphocytes obtained, 2 were positive for the rearrangement, and the positive rates for the rearrangement significantly differed between H/RS cells and the background lymphocytes (P=0.002).The results appear to support the hypothesis that H/RS cells originates from B cells, and a part of the background lymphocytes may possess neoplastic proliferation potentials to function as the precursors of H/RS cells.

To explore the origin and clonality of H/RS cells.Immunohistochemical method was used to detect the expression of B-cell-specific activator protein (BSAP) and CD(20) in 33 paraffin-embedded tissues of classical Hodgkin lymphoma (cHL). IgH gene rearrangement was detected in 33 paraffin-embedded cHL tissue and 6 microsectioned H/RS cell samples. The PCR products of a case of cHL and its microsectioned cells were sequenced.H/RS cells were positive for BSAP in 30 of 33 (90.91%) cHL cases and positive for CD(20) in 10/33 (30.30%) cases. There was a significant difference between the expression of BSAP and CD(20) in H/RS cells (P = 0.000). BSAP and CD(20) were positive in almost all B cells of lymph node reactive hyperplasia and malignant cells in B-cell lymphomas while were negative in all malignant cells of T-cell lymphomas. 16 of 33 cHL were positive for gene rearrangement, and microsectioned H/RS cells in 14 of 19 tubes displayed clonal bands of rearrangement. There was no significant difference among the rearrangement rates in tubes containing different numbers of H/RS cells (P = 0.280). Sequencing analyses of the PCR products from both paraffin-embedded tissue and microsection of the same patient revealed the rearranged V segments, but the sequences were not identical.H/RS cells were originated from B cells of different differentiation stage.

To evaluate significance of immunohistochemistry in Kikuchi's lymphadenitis (KFD).Biopsy specimens were obtained from 42 KFD cases for microscopic examination after the sections were stained with haematoxylin and eosin, and the immunohistochemical features were analyzed by monoclonal antibodies (CD20, CD8, CD45RO, CD57, CD68) and polyclonal antibody (myeloperoxidase, MPO).Morphologically, the lymph node lesions comprised various histiocytes, plasmacytoid monocytes, immunoblasts, small lymphocytes and nuclear fragments. In all the cases, the histiocytes were invariably observed and most of them were positive for CD68 and MPO. Immunoblasts and plasmacytoid monocytes were easily observed in proliferative stage. Immunohistochemical examination revealed strong focal T-cell positivity for the antibodies but with scarce B cell (CD20) and NK cell (CD57) positivity in the lesion area, where few or virtually no neutrophils were seen.Immunohistochemical analysis can be crucial for the differential diagnosis of KFD.