Composite lymphoma

Composite lymphoma [CL] is a rare disease that has been identified in recent literature. The term composite lymphoma was first proposed to denote the occurrence of more than one lymphoma in a single patient; however, the present accepted definition is the occurrence of 2 or more distinct lymphoma types in a single anatomic site. The condition could be concurrent or sequential. Unlike disease progression or transformation in lymphoma, CL should include two distinct clones proven by morphological and laboratory tests. No single definite mechanism has been suggested to explain the pathogenesis of the different types of CL. The etiology is variable, complex and differs according to the types of lymphomas involved. Several theories were proposed including clonal selection with additional mutational accumulation, genomic instability with genetic predisposition, common precursor cell and the aid of a viral factor, mostly EBV. The morphologic criteria must be confirmed by one or more tests including immunohistochemistry, flow cytometry, gene rearrangement by PCR, cytogenetics, FISH, in-situ hybridization, DNA sequencing and cDNA microarray. Results are more accurate using the laser capture micro dissection method. Many combinations of CL are reported, including: Multiple B-cell lymphomas; B-cell and T-cell lymphomas; NHL and HL; or complex B-cell, T-cell and HL cases. Due to the great advancement in molecular characterization of lymphoma, CL is being increasingly identified. It must be carefully diagnosed, because the multiple disease entities may have entirely different natural histories, prognosis and treatment modalities. Also, careful study of such cases may clarify the possible pathogenic mechanisms of the interrelationship of clonal evolution in lymphoma

Prognostic value of cyclin Dl and P53 protein in colorectal carcinoma

The multistep carcinogenic process of colorectal cancer involves a series of events as oncogenes, inactivation of suppressor genes and abnormalities in cell cycle regulating proteins. This study concerns altered expression and prognostic role of cyclin Dl and p53 in colorectal cancer patients. We evaluate nuclear accumulation of cyclin Dl and p53 immunohistochemically in archival tissue specimens from 41 primary colorectal adenocarcinomas. They had undergone surgery with a median follow up of 23 months [range 1-85 months]. Survival time was analyzed using Kaplan-Meier survival estimates and Cox proportional hazards model for nuclear accumulation of cyclin Dl and p53 with adjustments for other confounding demographic and clinical variables. The expression of cyclin Dl was identified in 41.5% while p53 was expressed in 58.5% of our cases. Cyclin Dl was statistically associated with p53, Dukes stage, nodal state, histologic grade and vascular invasion, but not with age, gender, location, size, gross picture, tumor type, bilharziasis or stromal reaction. p53 was significantly related to male gender and to mucinous and signet ring tumor types but not to either age, location, size gross picture, Dukes stage, nodal state, histologic grade, bilharziasis, stromal reaction or vascular invasion. Using Kaplan-Meier survival curve, cyclin Dl, p53, size, Dukes stage, nodal state and tumor type were significantly correlated with poor survival. By Cox multivariate regression analysis, p53 [relative risk 3.33, 95%-confidence interval 1.39-7.95; p=0.006], nodal state [relative risk 3.17, 95% confidence interval 1.31-7.68; p=0.01] and Dukes stage [relative risk 1.83, 95% confidence interval 1.06-3.15; p=0.027] were independent prognostic indicators in our colorectal adenocarcinoma cases. Our data suggest that cyclin D1/p53 pathway represent a frequent target of the multistep evolution of colorectal carcinoma. Nuclear p53 accumulation combined with nodal state and Dukes stage can predict the clinical behavior of a tumor and high risk colorectal cancer patients. Hence p53 might help to define, a subset of biologically unfavorable neoplasms and improve the prognostic accuracy for colorectal cancer

Histopathological, immuno-histochemical and electronmicroscopic study [EM] of soft tissue sarcoma

Sixty eight cases of soft tissue sarcoma [STS] selected from the files of Pathology Departments, Benha Faculty of Medicine-Zagazig University and National Cairo Institute- Cairo University, during the period from 1993 to 1997, were examined by light microscopy and class Wed into 44 differentiated cases [64.7%] and 24 undifferentiated cases [35.3%]. The differentiated cases were studied by histochemical and immunohistochemical stains using a panel of Antibodies. We applied the results of histological, histochemical and immunohistochemical reactivity of classified cases -on the 24 undifferentiated cases in trial to classify them. Histochemical and immunohistochemical stains were of most value in classification of 18 [75%] out of 24 undifferentiated cases as: 4 cases liposarcoma, 4 malignant fibrous histiocytoma [MFH], 4 leiomyosarcoma, 2 angiosarcoma, one case of monophasic synovial sarcoma and 3 cases of rhabdomyosarcoma. Combination of electron microscopic [E.M.] with light microscopic examination, [L.M], histochemical and immunohistochemical stains resulted in a specific diagnosis in 4 out of 6 unclassified cases [66.7%], This work supports the view that L.M. readily discriminate between differentiated tumor types. Special histochemical stains could be supportive and confirmation. Immunohistochemical markers together with appropriate clinical and histological features can minimize the number of undifferentiated sarcomas. In problematic cases, immunohistochemical and E.M. have complementary role

Follicular lymphoma: diagnostic value of Kappa/Lambda light chain mRNA restriction by in Situ hybridization

This study was initiated to test the validity of in situ hybridization [ISH] for kappa/lambda light chain mRNA restriction in the diagnosis of FL and compare its value with that of Bcl-2 oncoprotein immunodetection. This work comprised formalin fixed paraffin embedded tissues from 36 lymph node biopsies including 31 cases morphologically consistent with FL and five cases of reactive follicular hyperplasia [RFH] taken as control. Thirty out of 31 FL cases showed a restriction to either kappa or lambda light chain mRNA. Sixteen cases showed kappa restriction, whereas lambda restriction was seen in 14 cases. All lymph nodes with RFH demonstrated a strong hybridization signal with both kappa and lambda oligonucleotide probes. BCL-2 oncoprotein was detected in neoplastic follicles in 20 out of 31 FL cases and was negative in germinal centers of all RFH cases

Immunologic phenotyping of non-Hodgkin's lymphoma in Egyptian patients

Immunologic phenotyping was performed on 117 cases of nodal non- Hodgkin's lymphoma. Both frozen sections and cytopreps were studied. Monoclonal antibodies were used and staining was carried out by the ABC immunoperoxidases technique. The monoclonal antibodies used included OKT11 and LYT3 for pan T lymphocyte, Leu 2a for suppressor T, Leu 3a for helper T, B1 for pan B, kappa and lambda light chains for B subpopulations. Results showed predominance of B cell lymphoma [73.5%], mostly of kappa light chain, T cell lymphomas constituted only 14.5% of cases, while null lymphoma were 12%. There was significant correlation between the different morphologic subtypes of NHL according to the working formulation and their immunologic phenotypes [P <0.001]. The distribution of immunologic subtypes in relation to grades of lymphomas was as follows: Grade 1 [B [83.4%], T [8.3%], null [8.3%]]; grade 2 [B [85.2%], T [9.3%], null [5.5%]]; grade 3 [B [51.3%], T [25.6%], null [23.1%]]; denoting predominance of B cell lymphomas in grades 1 and 2, and T and null lymphomas in grade 3