Neurofibromatosis type 2 discordance in monozygous twins

Neurofibromatosis type 2 (NF2) is an autosomal dominant condition caused by pathogenic variants in the NF2 gene. The pathogenic variant is either inherited or obtained by de novo mutation, characterised by the presence of schwannomas, meningiomas and ependymomas. Here we report the presence of NF2 in one twin, with bilateral vestibular schwannomas and a pathogenic variant of the NF2 gene identified in both tumour and lymphocytes, while his monozygous brother remains asymptomatic. Imaging of the unaffected twin showed no tumour load and genetic testing via Sanger sequencing and Amplification Refractory Mutation System assay demonstrated low levels of expression of the NF2 variant in lymphocytes. Further testing on non-haemopoietic tissue showed little expression or absence of the pathogenic variant. Given there is no family history and the low level of the variant, we assume the pathogenic variant is a de novo mutation during embryogenesis. De novo mutations have been described as occurring at three possible time points in the creation of monozygous twins with different genetic make-up; prior to the twinning event, as a cause of the event, or after the twinning event. Of these options, we hypothesise that the discordance in the expression of the NF2 variant between these twins is likely due to a mutational event that occurred as a result of either of the latter two possibilities, between which we cannot determine. The pathogenic variant in lymphocytes was likely transferred between the twins through a shared blood supply in utero, and the non-haemopoietic samples that showed low levels of expression, were likely due to the presence of lymphocytic cells. Therefore, we have a discordance between monozygous twins at the NF2 gene.

Euglycemic diabetic ketoacidosis in type 2 diabetes mellitus treated with sodium-glucose cotransporter 2 inhibitors. A report on two cases

Sodium-glucose cotransporter 2 inhibitors are a new second-line medication in the management of hyperglycemia in type 2 diabetes. These drugs can be associated with the development of diabetic ketoacidosis (DKA) with normal or moderately increased blood glucose levels. This is a life-threatening clinical condition termed euglycemic DKA (euDKA), of which the diagnosis can be delayed due to the relative euglycemia. We report on two patients with type 2 diabetes who presented to the Emergency Department with malaise, nausea and vomiting. Both patients had been taking dapagliflozin for at least six months. A risk factor for the development of ketoacidosis, namely heavy alcohol consumption, was found in one of the patients. Arterial blood gas analysis showed severe metabolic acidosis with increased anion gap, positive serum and urine ketones and normal arterial lactate. The patients were treated in Internal Medicine with intravenous fluids, insulin, sodium bicarbonate and potassium. Dapagliflozin was stopped. Both patients recovered uneventfully. Even in the absence of significant hyperglycemia, accurate interpretation of arterial blood gas analysis and serum ketones should lead to correct diagnosis of euDKA.

Early repolarization syndrome and Brugada syndrome: is there any linkage?

Early repolarization syndrome (ERS) is characterized by the presence, in most cases in mid-to-lateral precordial leads, of a J wave on the downsloping portion of the QRS complex, followed by an elevation of the ST-segment with upward concavity. ERS is considered a benign electrocardiographic pattern of ventricular repolarization and, thus far, clinical interest in this syndrome has been confined to its differential diagnosis from myocardial infarction and pericarditis. Brugada syndrome (BS), an inherited cardiac disease first described in 1992, exhibits a characteristic electrocardiographic pattern consisting of a J wave mimicking a right bundle branch block with typical ST-segment elevation in the right precordial leads. Believed to be a normal repolarization variant for more than three decades, the syndrome is now known instead to be associated with a high incidence of life-threatening ventricular tachyarrhythmias and is responsible for a number of sudden deaths in young adults worldwide. Although clinical findings seem to differentiate the two syndromes, similarities between BS and ERS in terms of response to heart rate, pharmacologic agents, and neuromodulation could suggest a linkage in their pathophysiological mechanism. The authors review the clinical and experimental data in order to test this hypothesis.

Submassive acute pulmonary thromboembolism with normal D-dimer. A case report

Pulmonary thromboembolism is a relatively common disease in an Emergency Department. Diagnosis, often difficult, is based on careful evaluation of risk factors, clinical examination, radiological and laboratory investigations. Plasma D-dimer, a degradation product of cross-linked fibrin with low specificity and very high sensibility, is considered extremely useful as screening to rule out a pulmonary thromboembolism. We report the case of a 74 year old woman who presented in the Emergency Department suffering from the sudden onset of dyspnea 4 hours before. Plasma D-dimer (automated latex-enhanced turbidimetric test) was normal (253 ng/mL; normal value: 278 ng/mL), but spiral CT angiography showed a sub-massive thromboembolism of the principal branch of the right pulmonary artery, also involving the middle and the inferior lobar branches. A cardiac echo-color-Doppler demonstrated an enlargement of the right cardiac section with telediastolic pressure in the pulmonary artery of 74 mmHg (normal value 4-12 mmHg). A second measurement of plasma D-dimer, 12 hours later, remained in the normal range (274 ng/mL) and only after four days was there a significant increase (1017 ng/mL). The authors, taking the case as a starting point, stigmatize the difficulties that such diagnosis involves, despite indications of guidelines.

Brugada-like electrocardiographic pattern: a challenge for the clinician

A right bundle branch block with ST-segment elevation in the V1-V3 leads in characteristic coved or saddleback configuration may be encountered as an incidental finding. However, not all patients with a Brugada-like electrocardiographic pattern are affected by the Brugada syndrome; in fact, this pattern may also be found in healthy individuals. Whether symptomatic patients affected by the syndrome are at a high risk of developing life-threatening ventricular arrhythmias and should immediately receive an automatic, implantable defibrillator is open to debate, as is the clinical management of asymptomatic patients, because data from the scientific literature are controversial. Implications of the diagnosis and the treatment of this category of patients are discussed.

Anticholinergic toxicity associated with lupin seed ingestion: case report

We describe a case of acute poisoning in a 51-year-old female patient who presented to the Emergency Department with weakness, anxiety, dry mouth, bilateral mydriasis and lid drop. In differential diagnosis, botulism, Guillain-Barré syndrome and myasthenia gravis were considered, as well as cerebral haematoma because of a cranial injury a week before. Symptoms, which resolved within 12 h without any therapy, were instead related to the ingestion of lupin seeds.

Phosphatase isoenzymes as bone metastasis markers in prostatic carcinoma

Bone alkaline phosphatase (b-ALP) and tartrate resistant acid phosphatase (tr-ACP) are markers of the activity of osteoblasts and osteoclasts, respectively. We have already shown that the serum activity of these isoenzymes was elevated in breast cancer patients with bone metastasis (BM); we show here that the serum activity of b-ALP and tr-ACP were also elevated in prostate cancer patients with BM. Specificity and sensitivity of b-ALP for BM were 0.90 and 0.75, respectively; and for tr-ACP, 0.60 and 0.60, respectively. The accuracy of b-ALP as a BM marker was higher than the accuracy of usual markers of prostatic carcinoma (tartrate labile ACP [tl-ACP], prostatic acid phosphatase [PAP] and prostate specific antigen [PSA]). The highest value predictive of a positive bone scan was obtained with b-ALP (0.88); this increased to 0.97 when b-ALP was coupled with PAP.

Comparison of phosphatase isoenzymes PAP and PSA with bone scan in patients with prostate carcinoma

The aim of this study was to assess the diagnostic value of five biological markers--prostate acid phosphatase (PAP), prostate specific antigen (PSA), tartrate resistant (Tr-ACP), and tartrate labile (TI-ACP) acid phosphatases, and alkaline phosphatase bone isoenzyme (B-ALP)--for the detection of bone metastases in patients with prostate carcinoma. Using the Tc-99m HMDP bone scans of 80 patients scored from 0 (normal) to 2 (diffuse bone involvement) as the "gold standard," a receiver operating characteristic (ROC) analysis was performed. This method allows the determination of different threshold values (corresponding to different couples of sensitivity and specificity) for the assays. An ROC curve comparison was also performed. Results show that B-ALP is the best test for such detection (area under the ROC curve = 0.93; Spearman Rank correlation with bone scan r' = 0.81). Among the other markers, PSA was found to be the best (area under the ROC curve = 0.81; Spearman Rank correlation with bone scan r' = 0.58). In addition to the prostatic tumor markers (PSA and PAP), we suggest the use of the low-cost B-ALP assay in the follow-up of prostate carcinoma patients to determine the optimum moment to perform a bone scan. A normal result of this assay indicates a very low probability of bone metastasis; conversely, raising of B-ALP concentration must lead to a bone scan.

Bone scan and chemonucleolysis

This study is based on 20 patients who underwent bone scanning before and after chemonucleolysis (CN) for a herniated lumbar disk. It shows that chymopapain, the proteolytic enzyme used for CN, does not induce early or late bone lesions of the adjacent vertebral plates. Abnormal uptake by one of the vertebral plates indicates a "chemical discitis." The pattern observed on the bone scan is different from the one presented by patients with bacterial spondylitis.

Unusual site of extraosseous uptake of Tc 99m-HMDP due to subcutaneous heparin injections. Report of two cases

The soft tissue uptake of 99mTc-hydroxymethylene diphosphonate (99mTc-HMDP) due to subcutaneous injections of heparin calcium is reported in two patients with osteosarcoma. This uptake occurs in an unusual site, i.e. the shoulders and the anterior and posterior compartments of the upper arms.

Improvement of parathyroid Tl-Tc scintigraphy by using a new image subtraction method

Forty five thallium-technetium parathyroid scans were performed preoperatively in patients with a high suspicion of parathyroid adenoma or hyperplasia. The patients were imaged after sequential IV injection of 201Tl-thallous chloride (74 MBq) and 99mTc-pertechnetate (222 MBq) using a gamma camera with a pinhole collimator. According to surgical findings, the prevalence of parathyroid abnormalities was 42/45: single (34 patients) and double (1 patient) adenomas, hyperplasia (7 patients, 16 hyperplastic glands). Three methods of analysis of scintigraphic images were compared. Method one was the visual comparison of the thallium and the technetium images. Method two used the subtraction image obtained after normalisation. Method three used a new image comparison method which performs the geometric and gray level registrations of the two images and generates the image of the significant differences. Three observers were involved in the evaluation procedures. Surgery and histological examinations were taken as the gold standard. Results show that the sensitivity is increased by applying method three. The interobserver reproducibility of the results is also higher for method three. We conclude that an adequate image subtraction technique significantly increases the diagnostic value of parathyroid scintigraphy.

[Hemorrhagic Meckel's diverticulum. The place of abdominal scintigraphy with technetium 99m. Apropos of a case with gastric and pancreatic heterotopia]

A 12 year old child presented with a hemorrhagic Meckel's diverticulum, gastric heterotopia without identifiable ulceration and a totally aberrant pancreas. The diagnostic value of 99m-technetium abdominal scintigraphy in patients with Meckel's diverticula and gastric heterotopia, as well as the limits of this investigation, are discussed.

Metastatic calcification in the thyroid gland demonstrated on bone scan in a patient with primary hyperparathyroidism

Bone scanning agents are known to accumulate in extraskeletal sites. We report the case of a patient with primary hyperparathyroidism whose bone scan performed with [99mTc]HMDP revealed not only the classic pattern described in hyperparathyroidism, but also a striking visceral uptake in the lungs, heart, stomach, and thyroid gland. Metastatic calcification was found on histologic examination of the thyroid.

A new method for objective evaluation of cardiac parametric images

A new method for analyzing cardiac parametric images is introduced. Its original feature is the representation of local heart motion in a polar coordinate plane which makes the integration of the information contained in three parametric images possible. These images are calculated using first harmonic Fourier filtering and are the maximum volume image, the local ejection fraction image, and the phase image. The last two parametric images are considered as the complex ejection fraction parametric image which is described by a 2D distribution in the complex plane. This method is a generalized 2D version of the well-known phase histogram method. By segmenting the complex plane in which this representation is made, four indexes are defined called the index of hypokinesia, the index of asynergy, the mean phase shift in asynergic regions, and the mean ejection fraction in asynergic regions. The values of those indexes are used to assess the degree and extent of regional wall motion abnormalities. An automated classification as normal, hypokinetic, akinetic, slightly dyskinetic, and strongly dyskinetic made on the basis of the values of those indexes has been compared with a visual classification made by three observers in 219 studies. ROC curves show a good agreement between the automated and visual methods. This new method provides an efficient means of automatically classifying cardiac studies.