Mediastinal masses in infants and children

In a group of 93 pediatric patients with mediastinal masses, three quarters of them were diagnosed because they were symptomatic. Approximately one half of the masses were malignant, and of neurogenic or lymphomatous origin. Neurogenic tumors predominated before the age of 4 years, while lymphomas were most common beyond age 4. Two thirds of the malignancies were potentially curable by surgery, irradiation, and chemotherapy; 54% of the patients were salvaged. Enteric duplications, ganglioneuromas, bronchogenic cysts, hemangiolymphangiomas, thymic cyst, and teratomas were the most frequently occurring benign masses. Simple excision was uniformly effective in these lesions.     

Paresthesias: a practical diagnostic approach

Filarial nematodes are a cause of chronic debilitating diseases in the tropics. A hallmark of filariasis is the marked down-regulation and polarization of host immune responses, yet molecular constituents of parasites causing this state have remained undefined. We describe a 17-kDa antigen (Av17) of the rodent filarial parasite Acanthocheilonema viteae, which shows amino acid homologies to cystatin C, a major cysteine protease inhibitor belonging to family 2 of the cystatin superfamily. Av17 is released by filariae in vitro. Exported molecules of A. viteae worms are shown to markedly suppress mitogen-induced T cell proliferation of mice and jirds. Av17 accounts for 45.5% of this suppressive activity in the murine system. Recombinant Av17 (rAv17), expressed in Escherichia coli, exhibits biological activity as a cysteine protease inhibitor and was used to examine the immunomodulatory effects, rAv17 induces down-regulation of murine T cell responses to mitogens, to T cell receptor cross-linking by anti-CD3 antibodies and to specific antigens, and at the same time up-regulation of interleukin-10. Hence, this filarial cystatin is a likely effector molecule of immunomodulation and a potential target for antifilarial intervention.     

Transthoracic approach for removing adrenal masses

Early results with the transthoracic approach for removing adrenal tumors were evaluated. Between May 1994 and December 1995, 8 women and 5 men (aged 18-74) with adrenal masses underwent transthoracic adrenalectomy. All were excised successfully with short operation times (mean: 86 min), minimal blood loss (151 ml), limited use of parenteral analgesics (1.3 days), early ambulation (1.7 days post operation) and a short period of parenteral nutrition (1.7 days), resulting in reduced hospital stay (mean 6.7 days). With the transthoracic approach procedures are quick and safe even for large, malignant, and hormone-producing tumors. Recovery is easy with brief hospitalization. It provides excellent exposure of the adrenals, enables good control of bleeding vessels and is therefore our preferred method for removing adrenal masses.     

Secondary hypertension: a practical diagnostic approach

Secondary hypertension is a relatively uncommon, potentially reversible condition for which physicians should maintain a high index of suspicion. When a patient is found to have elevated blood pressure, a through history should be obtained and a complete physical examination should be performed. Depending on the findings, additional screening and diagnostic studies may be necessary. The most common causes of secondary hypertension are renal parenchymal disease, renovascular disease, coarctation of the aorta, pheochromocytoma, primary hyperaldosteronism, thyroid dysfunction and Cushing's syndrome.     

Recurrent anaphylaxis: diagnostic approach and management

The purpose of this study was to examine the effect of cycle rate (CR) variations on the metabolic cost and upper body forces during roller skiing with the V2-alternate technique on flat terrain. Nine highly skilled cross-country skiers roller skied at a paced speed of 18.0+/-0.1 km x h(-1) using their chosen CR, and CRs that were 10% slower and 20% faster. Oxygen uptake (VO2) was determined through collection of expired gases into a meterological balloon and poling forces were measured with piezoelectric transducers during the last 30 s of each four minute trial of roller skiing. One-way repeated measures ANOVA revealed that VO2 varied significantly with CR (p=0.02) with the chosen CR being significantly lower than the higher CR (p < 0.05). Poling forces and poling time were not significantly different among the CR conditions. The present results demonstrate that 1) an alteration in cycle rate affects metabolic cost of roller ski skating, 2) skiers tend to naturally select the most economical cycle rate, and 3) moderate variations in cycle rate do not appear to affect propulsive force generation through the poles in roller skiing.     

The thoracoscope as diagnostic tool for solid mediastinal masses

BACKGROUND: Despite the accuracy of percutaneous biopsy of mediastinal masses under CT scan or sonographic control, there is still a need for surgical biopsy because of difficult location or because of insufficiency of the percutaneous biopsy, especially for those tumors requiring an immunological classification. METHODS: The thoracoscopic approach to mediastinal masses is an alternative to the usual surgical biopsies performed through thoracotomy, sternotomy, or anterior mediastinotomy. The procedure is performed under general anesthesia and one-lung ventilation. RESULTS: In a series of 47 cases, a histological diagnosis was obtained in 44 cases (93.6%). There was one hemorrhagic complication requiring thoracotomy (2.1%). The mean postoperative duration of stay was 3.2 days. CONCLUSIONS: Thoracoscopy is the method of choice in case of failure or contraindication of percutaneous biopsy. There is still a role for mediastinoscopy in treating paratracheal lymph nodes.     

Pulmonary parenchymal manifestations surrounding small peripheral masses: pathologic correlation with chest radiographs and diagnostic value

The corrosion of aluminium (Al) in several brands of soft drinks (cola- and citrate-based drinks) has been studied, using an electrochemical method, namely potentiodynamic polarization. The results show that the corrosion of Al in soft drinks is a very slow, time-dependent and complex process, strongly influenced by the passivation, complexation and adsorption processes. The corrosion of Al in these drinks occurs principally due to the presence of acids: citric acid in citrate-based drinks and orthophosphoric acid in cola-based drinks. The corrosion rate of Al rose with an increase in the acidity of soft drinks, i.e. with increase of the content of total acids. The corrosion rates are much higher in the cola-based drinks than those in citrate-based drinks, due to the facts that: (1) orthophosphoric acid is more corrosive to Al than is citric acid, (2) a quite different passive oxide layer (with different properties) is formed on Al, depending on whether the drink is cola or citrate based. The method of potentiodynamic polarization was shown as being very suitable for the study of corrosion of Al in soft drinks, especially if it is combined with some non-electrochemical method, e.g. graphite furnace atomic absorption spectrometry (GFAAS).     

Mediastinal paraganglioma: a surgical experience

Between October 1960 and January 1991, 5 male and 9 female patients (mean age, 44 +/- 19 years) were seen at the Mayo Clinic because of mediastinal paraganglioma. Nine patients presented with hypertension. In these and an additional patient, the tumors were biochemically active. In 13 patients, the mediastinal mass was localized preoperatively. All patients with functioning tumors received alpha-adrenergic and beta-adrenergic blockade preoperatively. Total resection was performed in 11 patients and partial resection in 2. In 1 patient, the tumor was found at postmortem examination. Five lesions were grossly invasive and nine were noninvasive. Blood pressure returned to normal in 6 of the 8 hypertensive patients whose tumors were totally removed. In 4, catecholamine excretion normalized as well. Tumor multicentricity occurred in 6 patients. In 7 patients, the disease took a malignant course (metastases in 5 and progression of unresectable lesions in 2). The probability of 10-year survival after resection was 50% in the group with malignant tumors, and there were no deaths in the group with benign lesions. Analysis of the DNA cellular content showed no correlation between the ploidy pattern and the behavior of the disease.     

Mediastinal pseudotumor

A case of mediastinum vascular abnormality is presented consisting in the right side location of the aortic crutch and descending aorta. Besides an abnormality of brachiocephalic trunk issue and position is described. The possible diagnosis errors are discussed.     

Mediastinal lipomatosis

Mediastinal lipomatosis is a benign condition characterized by a large amount of mature adipose tissue within the mediastinum. It widens the mediastinum and may simulate mass lesions, thus leading to diagnostic errors. We describe a new case of a huge mediastinal lipomatosis and review 36 cases previously reported in the literature. Computed tomography has an important role in the diagnosis of this disease. To avoid invasive and unnecessary procedures, this diagnosis should be considered in any patient with Cushing's syndrome.     

Mediastinal mesenchymoma

An observation of a rare mediastinal tumor, malignant mesenchymoma, removed at thoracotomy in a woman of 30 is described. The cellular atypism of the tumor increased in the course of two relapses.     

Mediastinal bronchogenic cyst: diagnosis and follow-up

A 5-year-old girl with an asymptomatic posterior mediastinal cyst from birth was followed with repeated echocardiograms. The cyst developed communication with the bronchus spontaneously around 8 months of age without clinical symptoms. This was detected from the sudden disappearance of the mass on echocardiogram, and an unusual air-pocket on chest roentgenogram. Computed tomography (CT) of the chest confirmed the diagnosis of communicating bronchogenic cyst (BC). She was treated successfully with complete surgical excision of the cyst and closure of the defect in the bronchus. We emphasize that surgery is indicated in all mediastinal BCs because of potential complications.     

Pediatricians' diagnostic approach to pharyngitis and impact of CLIA 1988 on office diagnostic tests

OBJECTIVE: To determine the factors associated with an optimal diagnostic approach to a child with pharyngitis, characterize office laboratory methods for throat swab culture and group A streptococcal rapid antigen testing, and assess the potential impact of the Clinical Laboratory Improvement Amendments (CLIA) of 1988 on the performance of these tests. DESIGN AND SETTING: Mailed survey to all board-certified primary care pediatricians from seven western states with telephone follow-up for nonrespondents. OUTCOME MEASURES: Differences in practice characteristics and use of office laboratory tests for physicians who usually (> 80%) diagnose pharyngitis using a recommended approach vs those who follow this approach less often (< 50%); characteristics of physicians who indicate that they intend to discontinue office throat culture because of CLIA and those who will continue to perform this test also are compared. RESULTS: Responses from 531 pediatricians were analyzed. Forty-four percent diagnosed pharyngitis appropriately for more than 80% of patients, and 17% did so for fewer than 50%. Optimal diagnosis was significantly more common among physicians who cultured throat swabs in their office (relative risk, 1.40; 95% confidence interval, 1.19 to 1.66) and less common among solo practitioners (relative risk, 0.71; 95% confidence interval, 0.56 to 0.88). Factors that may decrease the sensitivity of office throat culture include short duration of incubation (59%), lack of quality control (51%), and limited education of the persons reading results (6%). With implementation of CLIA, 24% of pediatricians reported that they already have discontinued or will discontinue office throat culture, and 23% have discontinued or will discontinue antigen detection testing for group A streptococci. Those most likely to stop office culture include solo practitioners and practitioners who do not currently perform quality control of culture methods. CONCLUSIONS: Office culture for group A streptococci is strongly associated with an optimal diagnostic approach. Implementation of CLIA regulations may substantially decrease the number of physicians who perform this test. The balance between potential improvements in the quality of office culture with CLIA implementation and the decreased availability of this test needs to be assessed.     

Mediastinal teratomas: review of 15 pediatric cases

One hundred fifty-three children with a teratoma presented to one hospital between 1970 and March 1992. The clinical and pathological features of 15 patients with mediastinal teratomas are reviewed; six were newborn and nine aged from infancy to 13 years. Thirteen patients including the six newborns presented with respiratory distress and all 15 patients had a mass on chest radiograph. A definite diagnosis of teratoma was not made preoperatively in any of these patients. At operation, a median sternotomy was used to approach seven anterior tumors and a lateral thoracotomy performed in the other eight patients. Histologically two were mature, 10 had immature elements, and three were malignant teratomas. The patients with malignant tumors were all over 12 years of age and died within 6 months of treatment. All six neonates had immature teratomas. Raised serum alpha-fetoprotein levels provided useful markers in two patients with recurrent tumors. Three conclusions can be drawn: (1) mediastinal teratomas are rare in children and frequently are not diagnosed before operation; (2) in newborns these tumors may be immature and present with respiratory distress; and (3) a median sternotomy gives excellent exposure for anterior mediastinal tumors.     

Mediastinal cystic lymphangioma: report of two cases

Cystic lymphangioma is an extremely rare mediastinal benign tumor characterized by congenitally enlarged lymphatic vessels. It is often diagnosed incidentally because it is only symptomatic when it grows to be very large. We present two cases of mediastinal cystic lymphangioma and review the literature.