Pattern of Residual Submucosal Involvement after Neoadjuvant Therapy for Rectal Cancer: A Rationale for the Utility of Endoscopic Submucosal Resection.

Background and Objectives: Full-thickness trans anal local excision for tumors with favorable response following neoadjuvant therapy for locally advanced rectal cancer (LARC) is a common strategy for organ preservation, but it could be associated with a high rate of postoperative complications. We describe the incidence and pattern of submucosal involvement in surgical specimens following neoadjuvant therapy for LARC and whether limiting local excision of the residual tumor bed to only mucosal/submucosal layers of the rectal wall is sufficient for accurately predicting the ypT status of residual cancer, providing a pathological rationale to replace full-thickness local excision by endoscopic submucosal resection. Materials and Methods: This was a single-institution retrospective study conducted at a teaching community hospital. We reviewed clinical and pathological findings with slides of 82 patients diagnosed with LARC treated at our center between 2006 and 2020. Eligibility criteria mirrored our current organ preservation trials. Results: No tumor was found in surgical specimens in 28 cases (34%). Additionally, 4, 22, 27, and 1 cases were staged as ypT1, ypT2, ypT3, and ypT4, respectively. Residual malignant cells were found in the submucosal layer in 98% of cases with ypT+ stage, with 'skip lesions' in only 2% of cases. Conclusions: A very high incidence of submucosal involvement is noticed in residual tumors after neoadjuvant therapy, providing pathological rationale to study the role of endoscopic submucosal resection as a restaging tool for tumors with favorable response after neoadjuvant therapy when organ preservation strategy is pursued. This study was limited by its retrospective design and relatively small number of patients.

A Case of Esophageal Plasmablastic Lymphoma With a Literature Review.

Plasmablastic lymphoma is a rare B-cell lymphoma that is mainly associated with immunocompromised patients, such as those affected with human-immunodeficiency virus (HIV) or those who have received solid organ transplants; however, it has also been documented in immunocompetent patients. Moreover, there is also a strong association with Epstein-Barr virus (EBV). Although mainly found in the oral cavity, a few cases were documented to affect the gastrointestinal tract, and of those, only three cases were found to involve the esophagus, and we present the fourth case in a 48-year-old HIV-positive male.

Mast cell-induced immunopathology in recurrent pregnancy losses.

PROBLEM: Mast cells (MC) have been known to play an important role in inflammation and angiogenesis by secreting numerous mediators, such as proteases, gelatinases, and proteoglycans. Three different MC subtypes were found in the endometrial layers of the uterus. In this study, we aim to investigate the role of endometrial MCs in recurrent pregnancy losses (RPL). METHOD OF STUDY: Endometrial biopsy was performed 5-7 days post-ovulation (implantation window) in women with a history of two or more RPL (n = 46) and normal fertile women (n = 10). Quantitative RT-PCR was performed to detect the expression of various mast cell mediators. Endometrial samples were evaluated using immunohistochemistry for c-kit receptor (CD117) and tryptase (MC activation marker). RESULTS: Mast cells were present throughout the entire layers of the endometrium; their count was elevated in RPL patients as compared to controls. The gene expression of c-Kit receptor was not different between the study groups. There are significant increases in the mRNA expression of various mediators, that is, stem cell factor (P = 0.029), tryptase (P = 0.024), heparan sulfate (P = 0.0005), and MMP-2 (P < 0.0001) in women with RPL as compared to normal controls. Chymase gene expression was not detected in most of the endometrial samples. CONCLUSION: This study has shown that MCs are overactive in RPL patients by creating a pro-inflammatory milieu, suggesting a novel role in the immunopathology of RPL. Future studies are needed to better understand the role of MC in implantation and placental angiogenesis.

Prevalence of HHV-6 in endometrium from women with recurrent implantation failure.

PROBLEM: To study the prevalence of HHV-6 in endometrial biopsies among women experiencing recurrent implantation failure (RIF) after IVF/ET compared with controls. METHOD OF STUDY: Thirty women experiencing RIF after IVF/ET and 10 fertile women participated in the study. All women had endometrial biopsies taken in the luteal phase of their menstrual cycle for an endometrial immune profile (EIP) and HHV-6 mRNA as well as lymphocyte and granulocyte populations. The prevalence of HHV-6 in endometrial biopsies was determined, and biopsies for positive and negative expression of HHV-6 were compared with the results of their EIP and lymphocyte and granulocyte populations. RESULTS: Thirty-seven percentage of women with a history of RIF and 0% of controls demonstrated the presence of HHV-6 in their endometrial biopsies. No associations were found when the results of the endometrial immune profile were compared with the presence or absence of HHV-6. Significant increase in neutrophil-specific CD16b mRNA was found in HHV-6-positive samples, and the levels of B cells-related CD19 mRNA were lower in biopsies from women with RIF in comparison with normal controls. CONCLUSION: HHV-6 infection is an important factor in RIF.

The link between genetic polymorphism of glutathione-S-transferases, GSTM1, and GSTT1 and diffuse large B-cell lymphoma in Egypt.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma. A number of studies have examined the role of genetic polymorphisms in the risk of DLBCL, and several variants have been identified as potential susceptibility genes, of those glutathione-S-transferases T1 and M1 (GSTT1 and GSTM1). AIM OF THE WORK: The aim of the current study was to investigate the influence of inherited genetic polymorphisms of GSTM1 and GSTT1 genes on the susceptibility to DLBCL in Egypt. METHODS: Genotyping of the candidate genes was performed for 71 Egyptian DLBCL patients and 100 age- and gender-matched healthy controls by multiplex polymerase chain reaction technique. RESULTS: The frequencies of GSTT1 null, GSTM1 null, and dual null genotypes among DLBCL patients were 47.9, 52.1, and 23.9 % respectively. CONCLUSION: GSTT1 null genotype conferred almost fourfold increased risk of DLBCL (OR = 3.9, 95 % CI = 1.97-7.75), and the risk increased when confined to male patients (OR = 4.4, 95 % CI = 1.57-12.63), while GSTM1 null genotype was not associated with DLBCL risk. Further studies on the functional consequences of GSTT1 and GSTM1 genetic polymorphisms would pave the way to declare their role in the pathogenesis of DLBCL or as possible predictors for response to therapy.