Gastric Ewing Sarcoma identified on a Meckel's scan.

Ewing Sarcoma is a malignant small round blue cell tumor most commonly found in bones and soft tissues of the axial skeleton and extremities. The Ewing family of tumors, including peripheral neuroectodermal tumor, represent the second most common malignancy in the pediatric population and second most common primary bone tumor after osteosarcoma. In a majority of Ewing Sarcoma cases, there is a translocation between chromosomes 11 and 22. Extraskeletal Ewing Sarcoma of the stomach is exceptionally rare, with only a handful of case reports. Here we report a case of primary Ewing Sarcoma of the stomach found initially as a filling defect in the stomach on technetium-99m pertechnetate scintigraphy to evaluate for gastrointestinal bleeding.

Gastric Gastrointestinal Stromal Tumor Incidentally Detected With Meckel Scintigraphy.

A 17-year-old boy presented with fatigue, hypoxia, palpitations, and anemia (hemoglobin 3.5 g/dL). The search for the etiology of the bleeding began with a Meckel scan. A photopenic region in the gastric body and a region of abnormal tracer uptake in the right midabdomen were unexpected findings. Further investigation with ultrasound and computed tomography revealed a gastric mass, which proved to be a gastrointestinal stromal tumor at pathology. The right-sided tracer uptake resulted from stasis in the collecting system of a malpositioned right kidney, a cause of false uptake in a Meckel scan.

Bone Scintigraphic Findings in MRSA Osteomyelitis.

Methicillin-resistant Staphylococcus aureus osteomyelitis is a severe form of infection characterized by multifocal or multiple segmental osseous involvement and subperiosteal abscess formation with increased frequency of extraosseous complications including pyomyositis, septic thrombus, and septic arthritis. Bone scan showed long segment and/or multifocal involvement in 4 of 5 patients with areas of abnormal increased and decreased uptake. The clinical presentations included limp and/or pain. Joint involvement was seen in 4 cases. Bone scan abnormalities correlated well with MRI findings of severe and extensive bone disease, abscess formation, muscle, as well as joint and soft tissue involvement.

Comparison of PET-CT and conventional imaging in staging pediatric rhabdomyosarcoma.

BACKGROUND: Over the past decade, PET-CT has been used to assess rhabdomyosarcoma (RMS) in children. However, the role of PET-CT in staging RMS is unknown. PROCEDURE: Thirty subjects with RMS, median age 7.3 years, underwent PET-CT before therapy. PET-CTs and conventional imaging (CI) were independently reviewed by two radiologists and two nuclear medicine physicians to determine the presence of metastases. Accuracy, sensitivity, and specificity of PET-CT for detecting metastases were compared to CI using biopsy and clinical follow-up as reference standards. Maximum standardized uptake values (SUV(max)) of primary tumors, lymph nodes, and pulmonary nodules were measured. RESULTS: Primary tumors had an average SUV(max) of 7.2 (range, 2.5-19.2). Accuracy rates for 17 subjects with nodal disease were 95% for PET-CT and 49% for CI. PET-CT had 94% sensitivity and 100% specificity for nodal disease. Of seven pulmonary nodules detected by CI, three were not identified by PET-CT, two were indeterminate, and one was malignant with a SUV(max) (3.4) > twice that of benign nodules. Two subjects had bone disease; both were identified by PET-CT but only one by CI. Four subjects had bone marrow disease, two had positive PET-CTs but none had positive CI. Two subjects had soft tissue metastases detected by PET-CT but not CI. CONCLUSIONS: PET-CT performed better than CI in identifying nodal, bone, bone marrow, and soft tissue disease in children with RMS. CI remains essential for detection of pulmonary nodules. We recommend PET-CT for staging of children with RMS. CI with Tc(99m) bone scan can be eliminated.

Thoraco-abdominal enteric duplication cyst in association with neurenteric cyst, axial skeletal anomalies, and malrotation.

We report a case of a 2-year old boy with cervicothoracic deformity with vertebral rib anomalies, neurenteric cyst, separate thoracoabominal enteric duplication cyst, concurrent intestinal malrotation, and dextroposition of the heart. This combination of abnormalities is very rare. When these lesions are suspected, the patient must be investigated carefully. This case is presented to show the importance of cross-sectional imaging (MR and CT) for surgical planning.

Intussusception: clinical presentations and imaging characteristics.

OBJECTIVE: The objectives of this study were to determine the prevalence of clinical findings associated with intussusception based on age and to evaluate the test characteristics of the presence of air in the ascending colon on abdominal radiographs and the effectiveness of ultrasound in diagnosing intussusception. METHODS: This was a retrospective cohort study via chart review at a tertiary care center from January 2002 to December 2008. All children, aged 0 to 17 years, were identified with intussusception by International Classification of Diseases, Ninth Revision diagnostic coding. Charts were reviewed for clinical signs and symptoms at presentation, and all diagnostic studies were retrieved. A pediatric radiologist reviewed all films and ultrasounds. RESULTS: A total of 219 patients were identified with intussusception. One hundred thirty-two (60%) of patients were male; 127 (60%) were younger than 1 year (median, 7 months), 59 (27%) were 13 to 35 months (median, 23 months), and 33 (15%) were 3 years or older (median, 5 years). Children younger than 12 months were more likely to present with emesis, irritability, and guaiac-positive or grossly bloody stools compared with children older than 12 months (P < 0.05). In children older than 12 months, abdominal pain was the most common symptom (>96%). Plain films were performed in 192 children, and of these, 163 (85%) had no air present in the ascending colon. Abdominal ultrasound was performed on 63 patients, with 58 (92%) having findings consistent with intussusception. CONCLUSIONS: Abdominal pain is the most common complaint in all ages for children presenting with intussusception. In children younger than 12 months, the strongest clinical predictors are emesis, irritability, and blood in the stool. For diagnosing intussusceptions, radiographs of the abdomen performed well, but ultrasound performed better, diagnosing intussusception in 92% of the cases.

Recurrent idiopathic tumoral calcinosis in a child postoperatively.

Tumoral calcinosis is an uncommon disease characterized by the deposition of calcium salts and crystals in the periarticular soft tissues. It is almost entirely a disease of adults. Histological and radiologically, however, features of this condition are identical regardless of age. Lesions in adults usually involve the hip joint and tend to recur following surgery, whereas in children surgery is often curative. We report a case of recurrent tumoral calcinosis of the sternum of a Hispanic identical-twin female infant.

Uptake, transport, delivery, and intracellular activity of antimicrobial agents.

Antibiotic interactions with cells, including polymorphonuclear neutrophils, may influence therapeutic outcomes. Selected microbes (e.g., Legionella pneumophila) may survive ingestion by polymorphonuclear neutrophils and are thus protected from the action of antimicrobial agents that remain extracellular. Antibiotics that penetrate the cell can kill these microbes. Certain antibiotics are concentrated inside phagocytes, and when the phagocyte migrates toward the site of infection, the antibiotic-loaded cell carries the active agent to the infecting microbes. Active antibiotic may be released when the short-lived phagocyte dies. Even microbes considered to be extracellular pathogens, such as pneumococci, may survive high concentrations of antibiotic by entering cells. Antibiotics that penetrate and are active in cells may aid in enhancing therapeutic outcomes and in eliminating the carrier state for some pathogens.

Clostridium difficile toxin A alters in vitro-adherent neutrophil morphology and function.

The effects of purified toxin A in vitro on the shape and function of polymorphonuclear leukocytes (PMNL) were examined. Toxin A induced changes in adherent PMNL shape from a compact spherical or pyramidal shape to a thin and rope-like shape. This change in shape was accompanied by rearrangement of the F-actin cytoskeleton into aggregates. Toxin A-treated PMNL exhibited increased adherence and expressed less L-selectin and more Mac-1, compared with untreated PMNL. In contrast to these proinflammatory actions, toxin A impaired both directed and non-directed PMNL migration in response to N-formylmethionylleucylphenylalanine. In addition, toxin A decreased the oxidative activity of adherent PMNL stimulated by recombinant human tumor necrosis factor-alpha. These effects could be explained by toxin A-induced glucosylation of the signaling small-size guanine 5'-triphosphate-binding proteins of the Rho family in human PMNL.

Effect of antipyretic agents on uptake, transport, and release of antimicrobial agents by human polymorphonuclear leukocytes.

Polymorphonuclear leukocytes (PMNL) concentrate, transport, and release certain antimicrobial agents as they move in a chemotactic gradient. Antipyretic agents are frequently used in febrile patients receiving antimicrobial agents. Thus, the influence of ibuprofen, acetaminophen, and acetylsalicylic acid on uptake, transport, and release of azithromycin and moxifloxacin was studied. Uptake of the antimicrobial agents by human PMNL and the effect of the antipyretics were quantitated by bioassay of released antimicrobial agent. Transport and release were determined in chemotactic plates overlaid with sentinel bacteria that could detect transported and released antimicrobial agent. None of the antipyretics altered PMNL directed or non-directed movement. Uptake of azithromycin was significantly inhibited by acetylsalicylic acid but not by the other antipyretics. All of the antipyretic agents studied at therapeutic levels inhibited transport and release of both azithromycin and moxifloxacin. Administration of any of these antipyretic agents with antimicrobial agents that are transported and released by PMNL could compromise the efficacy of therapy.