Several studies have reported on the use of antibodies to monoclonal carcinoembryonic antigen (CEA) and vimentin (VIM) to distinguish between adenocarcinomas of endometrial (EM) and endocervical (EC) origin, with variably enthusiastic results. It is still unclear whether site of origin or pathway of differentiation (endometrioid [em] versus mucinous [m]) is more important in predicting immunohistochemical differences. In the present study, paraffin blocks from adenocarcinomas of known origin were retrieved and immunostained with monoclonal antibodies to VIM and CEA, as well as cytokeratins (CK) 4, 18, and 20, estrogen receptor (ER), and progesterone receptor (PR). Positivity was scored on a scale from 0 to 12, with emphasis on the pattern of differentiation (tumors with mixed patterns received separate scores for the em and m foci). Mean CEA scores for emEM (n = 27), mEM (17), mEC (10), and emEC (6) were 0.4, 0.9, 5.1, and 1.2, respectively. VIM scores were 6.9, 1.3, 0, 4.4; ER, 5.7, 4.2, 0, 1.6; PR, 7.6, 2.8, 0.1, 6.0; CK4, 9.2, 4.4, 8.5, 10.6; CK18, 6.4, 3.4, 5.5, 8.4; CK20, 0.7, 0, 0.5, 0.4. Both site and differentiation influenced these results, with the latter more important for VIM and PR, the former for ER, both for CEA (only mEC was frequently strongly positive), and neither for the CKs studied. No one stain or combination reliably distinguished endometrial from endocervical origin. The only immunostaining pattern that might identify a site of origin with more accuracy than hematoxylin & eosin evaluation alone is the combination of high VIM and ER scores in an endometrioid carcinoma, suggesting with about 95% accuracy in this series an endometrial origin of the tumor.

Our ability to identify germline variants in hereditary cancer cases remains challenged by the incomplete cataloging of relevant genes and lack of consensus on who should be tested. We designed a panel [hereditary oncogenesis predisposition evaluation (HOPE)] that encompasses most of the genes known to be associated with cancer development and tested its yield on more than 1300 samples of cancer patients. Pathogenic or likely pathogenic variants in high and intermediate risk genes were identified in 16, 23.9, 9.7 and 2.7%, respectively, of peripheral blood or normal tissue samples taken from patients with breast, ovarian, colorectal and thyroid cancer. To confirm specificity of these findings, we tested an ethnically matched cohort of 816 individuals and only identified pathogenic or likely pathogenic variants in 1.59% (0.98% in high risk and 0.61% in intermediate risk). Remarkably, pathogenic or likely pathogenic alleles in DNA repair/genomic instability genes (other than BRCA2, ATM and PALB2) accounted for at least 16.8, 11.1, 50 and 45.5% of mutation-positive breast, ovarian, thyroid and colorectal cancer patients, respectively. Family history was noticeably lacking in a substantial fraction of mutation-positive cases (63.7, 81.5, 42.4 and 87.5% in breast, ovarian, colorectal and thyroid, respectively). Our results show high contribution of germline mutations to cancer predisposition that extends beyond "classical" hereditary cancer genes. Family history was lacking in 63.5% mutation-positive cases, shows that hereditary cancer need not appear familial and suggests that relaxed selection of cancer patients for hereditary cancer panels should be considered.

Background: Plasmablastic lymphoma (PBL) is a rare subtype of non-Hodgkin's lymphoma. Characterized by its aggressive nature and plasmacytic differentiation, PBL remains a therapeutic and diagnostic challenge; it generally has a poor prognosis with very few long-term survivors and most patients dying within 2 years from initial presentation. PBL has been reported in several other countries; however, there have been no reported cases from Saudi Arabia. Here, we report 8 cases of PBL depicting the clinical presentation, immunocompetency, immunphenotypic characterization, diagnostic challenges and treatment outcome. Methods: The medical records were reviewed for clinical presentation, staging, laboratory data, radiological studies, treatments, and outcomes. A broad immunohistochemical panel consisting of CD45, CD3, CD20, CD79a, Pax5, CD38, CD138, MUM1, EMA, Kappa, Lambda, CD 56, CD30, Bcl-2, Bcl-6, Alk-1, Ki-67, EBV-LMP-1, and HHV8 was performed. Results: The tumors predominantly exhibited immunoblastic/plasmablastic or plasmacytic morphologic features and had a plasma cell-like immunophenotype. All cases were immunoreactive for CD38, CD138 and MUM1 confirming plasma cell differentiation of the tumor cells. CD20 was negative for all cases; whereas CD79a and Pax5 were weakly positive in 2cases. All 8 cases were EBV-LMP-1/EBER-1 negative, and 1 case was HHV8 positive. Similar to previously published studies, PBL in Saudi Arabia is characterized by male predominance (6/8), median age 51.5 years (mean age 46 years), associated with early dissemination, poor response to therapy, and limited survival (average survival time, 6.4 months, median overall survival 5.5 months). However, it does have some unique features. It occurs more commonly in immunocompetent persons (6/8, 75 %), is not associated with EBV infection (0/8), and nodal involvement (either primary or secondary) is common among patients (6/8). In addition, extra-oral sites are more common than oral/nasal cavities (7/8) and the c-myc gene is not common (1/8, 12.5 %).