Unilateral developmental absence of internal carotid artery with contralateral middle cerebral artery occlusion.

PURPOSE: Developmental absence of the internal carotid artery (ICA) is a rare congenital anomaly that results from an insult to the third aortic arch or dorsal aorta during early embryogenesis. Patients are often asymptomatic and are diagnosed incidentally during imaging to investigate neurological complaints. METHODS: We report a rare finding of an absent ICA during a workup of stroke in a middle-aged patient. RESULTS: CT brain perfusion (CTP) and CT angiography (CTA) revealed the right middle cerebral artery (MCA) thrombotic stroke with the demonstration of contralateral left ICA absence. The patient showed spontaneous recovery, and no thrombolysis or neurointervention was considered. CONCLUSIONS: This article highlights the importance of screening the head CT on bone window settings in case of the non-visualization of ICA to differentiate congenital absence from a steno-occlusive disease. It also illustrates the role of Magnetic resonance imaging (MRI) and MR Angiography (MRA) in demonstrating further possible vascular anomalies, structural brain malformations, and collateral circulation.

Fat-Containing Renal Cell Carcinoma Mimicking Angiomyolipoma: A Radiological and Histopathological Diagnostic Challenge.

A well-marginated fat-containing renal lesion gives strong suspicion of renal angiomyolipoma (RAML) that usually requires no surgical intervention. Radiologically, renal masses with a large amount of fat can rule out renal cell carcinoma (RCC). Calcifications are very infrequent in RAML. However, the presence of calcifications in a fat-containing renal lesion is highly suggestive of RCC. These lesions should undergo surgical resection and histopathological assessment to reach the right diagnosis and avoid poor outcomes if diagnosed late. We present a case of bilateral renal tumors, in which one of them radiologically contained abundant fat with calcifications on CT scan, which was confirmed to be an RCC on histopathological examination.

Heterotopic Pregnancy - A Diagnostic Challenge. Six Case Reports and Literature Review.

Heterotopic pregnancy is defined as the simultaneous presence of intrauterine and ectopic pregnancies. It is a rare condition, but due to the increasing use of artificial reproductive techniques, the incidence of heterotopic pregnancy is increasing. Most of the patients with heterotopic pregnancy have a previous history of infertility or tubal diseases. In this case series, we are presenting six cases of heterotopic pregnancy. Three of them had a history of assisted reproductive technique: one patient had in vitro fertilization with three embryos transferred, and two patients received follicular stimulating hormone therapy. In one of the cases, heterotopic pregnancy was missed on an initial transabdominal scan, and in the following weeks, it was diagnosed on transvaginal ultrasound. Five patients underwent laparoscopic salpingectomy, and one patient had laparotomy and then a salpingectomy was done. Follow-up ultrasound scans for intrauterine pregnancy (IUP) showed abortion of the IUP, except in one patient who delivered a healthy full-term baby via spontaneous vaginal delivery. Therefore, there is a need to develop diagnostic criteria to rule out heterotopic pregnancy if the patient underwent any type of assisted reproductive techniques. We are emphasizing the need for more careful scanning of the adnexa via transvaginal ultrasound, especially in high-risk patients, even if the intrauterine gestation is confirmed.

Sarcomatous Transformation of Recurrent Scapular Osteochondroma in a Patient with the Hereditary Multiple Osteochondromas: A Case Report and Literature Review.

Hereditary multiple osteochondromas (HMO) is an autosomal dominant disease diagnosed by the presence of two or more than two osteochondromas on radiographs. The majority of cases are asymptomatic. The presence of bony growth, pain, and compression of the surrounding structure are the usual presentations. Malignant transformation into chondrosarcoma is the most feared complication. A rapid increase in size, recurrence after the surgical excision, and infiltrating mass may suggest the conversion into chondrosarcoma. Radiological imaging helps in diagnosing malignant transformation. MRI is the investigation of choice to exclude cancer. We hereby present a case of multiple osteochondromas with suspected malignant transformation due to rapidly increasing painful osseous swelling.

A Rare Case Report of Extra-adrenal Pheochromocytoma with Normal Blood Pressure: Is that Possible?

Extra-adrenal pheochromocytoma is uncommon and usually secreting nor-epinephrine. We are presenting a possible case of extra-adrenal pheochromocytoma in a 68-year-old male who was admitted to Queens Hospital Center complaining of shortness of breath for two days. Physical examination was unremarkable except tachycardia. Ventilation/perfusion (V/Q) scan showed the intermediate probability for pulmonary thromboembolism. Computed tomography (CT) chest confirmed the presence of old embolism and showed the 1.1 cm nodule in the left upper lobe. He suddenly collapsed and went into cardio-respiratory failure and attempts to resuscitate were futile. Results for pheochromocytoma workup received after the patient has passed away and it showed elevated levels of 24-hour urine metanephrine, normetanephrine, and Vanillylmandelic acid (VMA). In our patient, CT abdomen did not identify any mass in the adrenal gland or at the bifurcation of the aorta. The extra-adrenal tumor can secrete enough epinephrine to negate the hypertensive effect of norepinephrine. The clinician should be aware of the possibility that tachycardia could be a presenting symptom in pheochromocytoma although the patient is normotensive.

Pheochromocytoma Secreting Large Quantities of Both Epinephrine and Norepinephrine Presenting with Episodes of Hypotension and Severe Electrolyte Imbalance.

Pheochromocytoma is a rare tumor usually arising from the adrenal medulla (strictly speaking, those arising outside the adrenal gland are called paragangliomas). We report a case of pheochromocytoma presenting as orthostatic hypotension and electrolyte imbalance. A 51-year-old woman was admitted because of vomiting and chest pain. She had fluctuating blood pressure (BP) with episodes of orthostatic hypotension. Computed tomography pulmonary angiogram was performed to rule out pulmonary embolism; it showed a clear chest, but an incidental right suprarenal mass. The biochemical analysis supports the diagnosis of pheochromocytoma. Her electrolyte panel revealed persistently low potassium, calcium, and magnesium levels despite aggressive replacement. We speculated that hypotension was mainly due to vasodilatation caused by excess plasma epinephrine and prescribed doxazosin and a nonselective beta-adrenergic blocker which stabilized BP. The right adrenal tumor excised, and postoperatively she remained hemodynamically stable with no hypotensive episode. Laboratory data taken six weeks after surgery show normal 24-hour urine metanephrine and normetanephrine and normal serum magnesium and calcium levels. This case report highlights the variable presentation of pheochromocytoma. We also discuss the probable mechanisms of electrolyte imbalance in our case.

Follicular Variant of Papillary Thyroid Carcinoma Presented as Autonomous Functioning Thyroid Nodule: A Case Report and Review of Literature.

Follicular variant of papillary thyroid carcinoma (FVPTC) presented as an autonomous functioning thyroid nodule is a rare finding. We reported a case of 70-year-old male presented with complaints of palpitation and heat intolerance. On palpation, we found a thyroid nodule of 4 cm in the left lobe. Thyroid function tests revealed hyperthyroidism, and radioactive iodine uptake scan (RAIU) showed increased uptake in the left lobe consistent with a hot nodule. The probability of the benign nature of hyperfunctioning thyroid nodule discussed but patient requested further workup to rule out any remote possibility of thyroid cancer. We performed a fine needle aspiration (FNA), and the cytological examination suggested the possibility of thyroid carcinoma. The patient underwent total thyroidectomy, and histological examination revealed follicular architecture with nuclear features of papillary carcinoma in 1 cm area of the thyroid nodule. In the review of the literature, we identified the following seven cases of FVPTC arising within a hyperfunctioning thyroid nodule.

Characterization of human monoclonal antibodies that neutralize multiple poliovirus serotypes.

Following the eradication of wild poliovirus (PV), achieving and maintaining a polio-free status will require eliminating potentially pathogenic PV strains derived from the oral attenuated vaccine. For this purpose, a combination of non-cross-resistant drugs, such as small molecules and neutralizing monoclonal antibodies (mAbs), may be ideal. We previously isolated chimpanzee and human mAbs capable of neutralizing multiple PV types (cross-neutralization). Here, we describe three additional human mAbs that neutralize types 1 and 2 PV and one mAb that neutralizes all three types. Most bind conformational epitopes and have unusually long heavy chain complementarity determining 3 domains (HC CDR3). We assessed the ability of the mAbs to neutralize A12 escape mutant PV strains, and found that the neutralizing activities of the mAbs were disrupted by different amino acid substitutions. Competitive binding studies further suggested that the specific mAb:PV interactions that enable cross-neutralization differ among mAbs and serotypes. All of the cloned mAbs bind PV in the vicinity of the "canyon", a circular depression around the 5-fold axis of symmetry through which PV recognizes its cellular receptor. We were unable to generate escape mutants to two of the mAbs, suggesting that their epitopes are important for the PV life cycle. These data indicate that PV cross-neutralization involves binding to highly conserved structures within the canyon that binds to the cellular receptor. These may be facilitated by the long HC CDR3 domains, which may adopt alternative binding configurations. We propose that the human and chimpanzee mAbs described here could have potential as anti-PV therapeutics.

AParadigm Shift: The New Novel Oral Anticoagulation Agents.

Atrial fibrillation (AF) is the most common arrhythmia and represents one-third of the arrhythmia-related hospital admissions in the developed countries. Embolic strokes associated with AF are more severe and disabling. Thromboembolic stroke prevention is a major goal in treatment of AF and Warfarin has successfully served this purpose for many years. Drug-drug interaction and regular monitoring with Warfarin pose a significant challenge where health care system has limited resources; and lack of a well-structured health system, hinders regular International Normalized Ratio (INR) monitoring. Novel oral anticoagulants (NOACs) have opened up a new exciting chapter in the field of anticoagulation in non-valvular atrial fibrillation (NVAF). This review discussed the landmark trials that led to the development of NOACs and explored the potentials of these new agents with simultaneous comparison of Warfarin.