Search

Aims: An accurate diagnosis of T-cell/histiocyte-rich large B-cell lymphoma needs to take into consideration those forms of Hodgkin's lymphoma also characterized by a predominance of small lymphocytes and histiocytes, i.e. nodular lymphocyte predominance Hodgkin's lymphoma and lymphocyte-rich classical Hodgkin's lymphoma. We have studied the clinical, phenotypic and genetic features of a series of 12 cases of T-cell/histiocyte-rich large B-cell lymphoma along with 18 cases of Hodgkin's lymphoma for comparative purposes. Methods and results: Of the Hodgkin's lymphoma cases, there were 11 lymphocyte predominance type and seven classic type. T-cell/histiocyte-rich large B-cell lymphomas presented usually in advanced stages (III or IV in 11/12 cases), frequently with ‘B’ symptoms (6/9 cases), and followed a more aggressive course than Hodgkin's lymphoma (4/8 patients died due to the tumour in T-cell/histiocyte-rich large B-cell lymphoma versus 0/15 in Hodgkin's lymphoma). T-cell/histiocyte-rich large B-cell lymphoma cases showed diffuse effacement of the nodal architecture by a proliferation of scattered large atypical B-cells obscured by a background of small T-lymphocytes (more CD8+, TIA1+ than CD57+). Five cases showed also a prominent histiocytic component. The large B-cells expressed CD45 and often EMA (6/10 cases). On the other hand, CD30, CD15 and latent infection by Epstein–Barr virus (EBV) were generally lacking. bcl6 and CD10 were, respectively, detected in 6/6 and 1/5 cases. Conventional polymerase chain reaction (PCR) showed monoclonal immunoglobulin heavy chain (IgH) gene rearrangements in all T-cell/histiocyte-rich large B-cell lymphomas studied (5/5), but did not detect any case with t(14;18) involving the major breakpoint region (0/4). Conclusions: The differential diagnosis of T-cell/histiocyte-rich large B-cell lymphoma from Hodgkin's lymphoma is facilitated by the integration of different immunophenotypic, molecular and... [ABSTRACT FROM AUTHOR]

Aims Overexpression of CD44v6 in colon crypt epithelial cells has been suggested to have diagnostic potential in differentiating ulcerative colitis from other forms of colon inflammation, including Crohn's disease. Our aim was to determine the value of CD44v6 expression in inflammatory bowel disease (IBD) and to look for possible associations between CD44v6 expression and activity of this disease. Methods and results CD44v6 expression was studied using immunohistochemical techniques in 100 surgical and endoscopic colon samples of ulcerative colitis (n = 71) and Crohn's disease (n = 29), and in every case disease activity was studied by endoscopy and microscopic examination. Fifty-five of 71 (77.5%) samples of ulcerative colitis showed monoclonal antibody 2F10 stained colon epithelium, as did 16 of 29 (55.2%) samples of Crohn's disease. CD44v6 was detected in 88.2% (15 of 17) of cases of IBD with severe disease activity and in 100% of eight cases of severe ulcerative colitis. Our study showed a strong association between CD44v6 expression and the activity of IBD (P = 0.007). Conclusions CD44v6 expression in IBD is significantly associated with activity detected by means of endoscopy and pathological features. Our data suggest that CD44v6 expression may have some usefulness in conjunction with other factors as a means of evaluating the disease activity. Moreover, CD44v6 expression was higher in ulcerative colitis than Crohn's disease (P = 0.02), although this does not confirm the utility of monoclonal antibody 2F10 in differential diagnosis between ulcerative colitis and Crohn's disease, as there was a notable percentage of positive samples of Crohn's disease. [ABSTRACT FROM AUTHOR]