Ipsilateral renal dysgenesis or agenesis with tubulocystic anomalies of the mesonephric duct

Tubulocystic anomalies of the mesonephric duct (MND) are a rare group of related entities with a perplexing clinical presentation. Ultrasound is a useful screening investigation, which can help identify a dysplastic kidney or point to renal agenesis and identify cystic or tubulocystic changes in the structures derived from the ureteric bud or MND. Further evaluation with MRI can help in characterisation and direct management. The presence of a dysplastic kidney or absence of a kidney should prompt further evaluation for associated ureteric abnormalities such as ectopic insertion or ureterocoele, which could lead to a diagnosis of tubulocystic anomaly of the MND.

Contribution

The authors describe two cases, briefly outline the diagnostic approach and summarise the literature on management. Reporting radiologists should be aware of these entities.

Hyperplastic Anterior Choroidal Artery—A Rare Variant Detected on MR Angiography

Introduction  The anterior choroidal artery is a branch of the terminal internal carotid artery (ICA) that is often an incidentally detected anomaly. The hyperplastic variant has been linked with an increased risk of aneurysms. We explore the role of magnetic resonance (MR) angiography in the detection of this variant and its impact of presentation of patients.

Patient Presentation  A 62-year-old diabetic and hypertensive male came to the casualty with complaints of giddiness, left-sided weakness, and loss of coordination for the last 2 to 3 days. He was provisionally diagnosed with a posterior circulation stroke.

Management and Outcome  Magnetic resonance imaging of brain revealed an acute infarct in the right thalamus and the midbrain. Time-of-flight angiography sequences were done that showed hypoplasia of the A1 segment of the left anterior cerebral artery, fetal origin of the right posterior cerebral artery, narrowing of the left ICA, and a hyperplastic left anterior choroidal artery. He was managed conservatively with antiplatelets. He later underwent a digital subtraction angiography that revealed significant narrowing of the left ICA for which he was advised carotid stenting. However, the patient was unwilling for the procedure and was discharged on oral medication with stable vitals.

Conclusion  Anatomical variations in the intracranial vasculature impact ischemia territory and the approach to intracranial pathology. Hyperplastic anterior choroidal artery results from the abnormal persistence of fetal pattern of vascular supply. It is important to recognize the presence of a hyperplastic anterior choroidal artery as it impacts both disease presentation and management of these patients. MR angiography allows for noninvasive and reliable detection of these anomalies in patients without the risks associated with radiation or contrast exposure in conventional/computed tomography angiography.

A study on the frequency and clinicopathological correlates of mismatch repair-deficient colorectal cancer

Introduction

Microsatellite instability is an important pathway of tumorigenesis in colorectal cancer, and there is a need to understand its genetic and phenotypic profile. This study aimed to study the occurrence of deficient mismatch repair (dMMR) in an Indian cohort of patients and document the corresponding clinicopathological correlates.

Materials and Methods

This is a retrospective study of patients admitted between January 2016 and December 2017. dMMR data from immunohistochemistry reports were correlated with histopathological data and demographic details. The data were then analyzed in terms of means and percentages.

Results

About 29% of cases were found to be dMMR and 66.7% of dMMR tumors occurred in males. About 44.4% of dMMR tumors occurred in the ascending colon. MSH2 loss was seen in 44.4% of cases while MLH1 loss was seen in 33.3%, and there were two cases with loss of PMS1.

Conclusions

dMMR tumors in our study were more common in males, presented earlier, were bulky, were less likely to show lymphovascular or perineural invasion, had lower preoperative carcinoembryonic antigen levels, and yielded high number of lymph nodes. Expected differences in age, stage, and grade were not observed. Compared to other studies, a higher proportion of cases in our study had MSH2 and PMS2 loss.

Autoimmunity and pulmonary hypertension: a perspective

The association between autoimmunity and pulmonary arterial hypertension (PAH) has been appreciated for >40 yrs, but how autoimmune injury might contribute to the pathogenesis of this disease has only been examined in a case-specific manner. It is becoming increasingly clear that a variety of diverse clinical diseases, ranging from viral infections to connective tissue disorders, can culminate in pulmonary vascular pathology that is indistinguishable. Is there a hitherto unappreciated biology that unites these seemingly unrelated conditions? The answer to this question may come from the increasing body of evidence concerned with the central importance of regulatory T-cells in preventing inappropriate B-cell activity. Two striking similarities between conditions associated with severe angioproliferative pulmonary hypertension are a defect in the CD4 T-cell compartment and auto-antibody production. Pathogenic auto-antibodies targeting endothelial cells are capable of inducing vascular endothelial apoptosis and may initiate the development of PAH. The present review will focus on what is known about autoimmune phenomena in pulmonary arterial hypertension patients, in order to better consider whether an early loss of self-tolerance followed by autoimmune injury could influence the early development of severe angioproliferative pulmonary hypertension.

Primary pulmonary hypertension, Castleman's disease and human herpesvirus-8

Primary pulmonary hypertension (PPH) and Castleman's disease (CD) are rare conditions infrequently encountered in clinical practice. In this paper, two patients diagnosed with both of these diseases are reported. The authors speculate that rather than being a chance occurrence, these conditions are linked by a common angio-proliferative mechanism. Therefore, an association between infection with the human herpesvirus-8 and the diseases of PPH and CD was sought. Evidence of human herpesvirus-8 infection was found in the lung tissue and, specifically, in the plexiform lesions from one of the patients.