Neonatal alveolar rhabdomyosarcoma with skin and brain metastases.

BACKGROUND: Approximately 5-10% of patients with rhabdomyosarcomas (RMS) are diagnosed during the first year of life, and their clinical characteristics have been well documented. However, because RMS rarely occurs during the neonatal period, little is known about neonatal RMS. METHODS: Four patients with neonatal RMS were treated at St. Jude Children's Research Hospital between 1962 and 1999. The authors report the results of a review of these patients and of cases described in the literature. Clinical, radiologic, and pathologic features of these patients and their outcomes were evaluated. RESULTS: One patient with embryonal RMS was treated successfully with a combination of systemic chemotherapy and local control measures. The other three patients had alveolar RMS. Two of them had multiple skin and subcutaneous metastatic nodules at the time of diagnosis and developed brain metastases early in their course. In one of these patients, the PAX3-FKHR fusion transcript was detected. Three other similar cases of neonatal alveolar RMS with metastases to the skin and brain have been reported in the literature. CONCLUSIONS: A distinct syndrome of neonatal RMS is described. This syndrome is characterized by alveolar histology, multiple skin and subcutaneous metastases, and fatal outcome as the result of early brain metastasis.

Malignant and benign bone tumors.

The authors have intentionally included some confusing examples to demonstrate that the imaging findings of benign and malignant pediatric bone lesions are not always pathognomonic. The radiologist's role is to recognize malignant bone lesions and encourage the prompt referral of these patients to an appropriate institution for biopsy and treatment. The radiologist must also be able to identify benign lesions and help determine whether these lesions require biopsy and intervention or simply observation.

Tumor volume or dynamic contrast-enhanced MRI for prediction of clinical outcome of Ewing sarcoma family of tumors.

BACKGROUND: The identification of risk factors that predict poor clinical outcome at the time of diagnosis could lead to intensified early therapy and improved outcome for pediatric patients with Ewing sarcoma family of tumors (ESFT). OBJECTIVE: To compare the effectiveness of static magnetic resonance (MR) imaging measurements of tumor volume with variables obtained by dynamic contrast-enhanced MR imaging (DEMRI) in predicting ESFT outcome. METHODS: MR examinations that included DEMRI were retrospectively reviewed. The analyses included 45 examinations of 21 patients with ESFT (performed from 1992 to 1996). Tumor volumes were measured on the static MR images, and the regions of interest were selected for DEMRI analysis. The relationships of static MR imaging and DEMRI variables with the probability of progression-free survival (PFS) and disease-free survival (DFS) were determined. RESULTS: Larger tumor volume at the time of diagnosis predicted poorer PFS and DFS estimates. No DEMRI variable predicted outcome. CONCLUSION: Determination of tumor volume by static MR imaging at the time of diagnosis is a simple and reliable method of predicting the clinical outcome of patients with ESFT. DEMRI is not as reliable a technique as static MR imaging for predicting the outcome of these patients.

Accuracy of percutaneous lung biopsy for invasive pulmonary aspergillosis.

BACKGROUND: Invasive pulmonary aspergillosis is fulminant and often fatal in immunosuppressed patients. Percutaneous biopsy may select patients who could benefit from surgical resection. OBJECTIVE: We sought to determine the accuracy of percutaneous biopsy for pediatric invasive pulmonary aspergillosis. MATERIALS AND METHODS: We retrospectively reviewed 28 imaging-guided percutaneous biopsies of the lungs of 24 children with suspected pulmonary aspergillosis. Twenty-two were being treated for malignancy and two for congenital immunodeficiency; 15 had received bone-marrow transplants. The accuracy of the percutaneous lung biopsy was determined by subsequent surgical resection, autopsy, or clinical course. RESULTS: Histopathological studies showed ten biopsy specimens with septate hyphae, indicating a mold, and seven with Aspergillus flavus colonies in culture. The remaining 18 biopsies revealed no fungi. No patient had progressive aspergillosis after negative biopsy. Invasive pulmonary mold was detected by percutaneous biopsy with 100% (10/10) sensitivity and 100% (18/18) specificity. Percutaneous biopsy results influenced the surgical decision in 86% (24 of 28) of the cases. Bleeding complicated the biopsy in 46% (13/28) and hastened one death. CONCLUSION: Percutaneous biopsy of the lung is an accurate technique for the diagnosis of invasive pulmonary aspergillosis and correctly determines which immunosuppressed pediatric patients would benefit from therapeutic pulmonary resection.

Hepatic veno-occlusive disease in children undergoing bone-marrow transplantation: usefulness of sonographic findings.

BACKGROUND: Reports of the usefulness of ultrasonography in the diagnosis of hepatic veno-occlusive disease (HVOD) have presented conflicting results. OBJECTIVE: To determine the usefulness of gray-scale or Doppler ultrasonographic measurements in the diagnosis of HVOD in pediatric patients undergoing BMT. MATERIALS AND METHODS: We prospectively obtained 202 serial sonograms on 48 patients and examined the association between the clinical diagnosis of HVOD (McDonald criteria) and eight ultrasound parameters, including the hepatic artery resistive index (HARI), direction and velocity of portal venous flow, and thickness of the gall bladder wall. RESULTS: HVOD developed in 29 of the 48 patients. The portal venous velocity increased after BMT in the group without HVOD and decreased in the group with HVOD; this difference was significant (P = 0.01). However, there was a great deal of variability in velocity measurements for individual patients. The mean HARI was 0.64 in the group with HVOD and 0.63 in the group without HVOD, and there was no difference between the two groups in the pattern of change in HARI relative to the day of BMT (P = 0.4). There was also no significant difference in thickness of the gallbladder wall between the two groups (P = 0.6). CONCLUSION: No ultrasound parameter studied was as useful as the McDonald criteria for diagnosing HVOD.

Liver biopsy methods for pediatric oncology patients.

BACKGROUND: Liver biopsy is a high-risk procedure in oncology patients, and optimal methods for children have not been established. OBJECTIVE: To assess the effectiveness and safety of two methods of performing liver biopsy in pediatric oncology patients. MATERIALS AND METHODS: Between May 1997 and July 1999, 51 liver biopsies (22 percutaneous and 29 transjugular) were performed. The 22 percutaneous biopsies (13 focal hepatic lesions and 9 general liver biopsies) were performed under sonographic guidance; 21 used a spring-loaded needle (usually 18 G). In 21 patients, a coaxial sheath was used to inject a slurry of microfibrillar collagen into the needle track. The 29 transjugular general liver biopsies were performed with a 19-G spring-loaded needle, under sonographic and fluoroscopic guidance. The transjugular technique was used for children with thrombocytopenia, coagulopathy, ascites, or recent bone-marrow transplantation. RESULTS: All biopsies yielded sufficient tissue for diagnostic studies. Bleeding occurred after 3 of 21 percutaneous biopsies, despite coaxial track embolization. No bleeding or other major complication occurred after transjugular biopsy. CONCLUSION: Coaxial percutaneous biopsy with track embolization was effective, but was not complication-free; it should be reserved for focal lesions or for patients at low risk of bleeding. Transjugular liver biopsy is safe and effective for use in high-risk pediatric oncology patients.

Accuracy of MR imaging for detecting epiphyseal extension of osteosarcoma.

BACKGROUND: Too few patients are receiving epiphyseal-sparing limb salvage procedures for osteosarcoma. OBJECTIVE: To determine how magnetic resonance (MR) imaging can best predict the epiphyseal extension of osteosarcoma. MATERIALS AND METHODS: Forty children underwent complete pretreatment static and dynamic contrast-enhanced MR imaging (DEMRI). Static MR images [T1-weighted and short tau inversion recovery (STIR)] of the epiphyses were read in three ways: (1) for suspicion of any abnormality (tumor or edema), (2) for suspicion of tumor, excluding suspected edema, and (3) validating the second method by using a scale to rate the likelihood of tumor. Presentation imaging was compared to histopathologic findings after chemotherapy and resection. The receiver operating characteristic (ROC) method was used to analyze the scaled ratings of static MR and DEMRI values. RESULTS: At delayed resection, 20 of 40 children with osteosarcoma had confirmed epiphyseal tumor; however, 32 epiphyses were abnormal on STIR and 28 abnormal on T1. Differentiating suspected tumor from edema increased the accuracy to an Az (area under the ROC curve) of 0.94 for both T1-weighted and STIR static sequences. T1-weighted MR had better specificity and STIR better sensitivity at any given rating. DEMRI was slightly less accurate (Az = 0.90). CONCLUSION: Static MR imaging most accurately detected epiphyseal extension of osteosarcoma when readers distinguished suspected tumor from edematous or normal tissue.

Needle localization of small pediatric tumors for surgical biopsy.

BACKGROUND: Small pediatric tumors may be difficult to biopsy or resect. OBJECTIVE: To examine the benefits of needle localization of a variety of small pediatric tumors before surgical biopsy or excision. MATERIALS AND METHODS: Seven patients aged 1-19 years underwent 12 procedures for needle localization of suspected tumor. Two patients had undergone previous biopsies without needle localization with negative results. Computed tomography (four patients) or ultrasonography (three patients) guided needle placement. Each patient had suspected tumor(s) in 1-3 anatomical sites, including thigh (7), lung (2), parasacral region (2), and iliac bone (1). RESULTS: All 12 lesions (9 less than 1 cm3 in volume) were successfully localized for excision or biopsy. Three small (<1 cm3) soft-tissue lesions (two ganglioneuroblastomas and one ganglioneuroma) were excised from one patient, a 0.65-cm3 residual soft-tissue sarcoma from another; and recurrent bilateral teratomas from a third. Two peripheral primitive neuroectodermal tumors were excised with positive margins from a fourth patient. Two lesions contained only fibrosis, as determined by histopathology. Two other patients underwent thoracoscopic removal of lung metastases that were less than 0.1 cm3. CONCLUSION: Needle localization allows effective and less invasive excision or biopsy of a variety of small pediatric soft-tissue lesions.

The use of oral pentobarbital sodium (Nembutal) versus oral chloral hydrate in infants undergoing CT and MR imaging--a pilot study.

BACKGROUND: Chloral hydrate, a commonly used oral sedative for infants undergoing imaging examinations, has a bitter taste and requires relatively large volume, provoking unpleasant reactions from the infants. Experience with an alternative sedative, oral pentobarbital (Nembutal), has not been reported for infants. OBJECTIVE: To compare patient acceptance of oral Nembutal and oral chloral hydrate for sedation of infants up to 12 months of age. METHODS AND MATERIALS: Fifty-four infants (mean age: 7 months) were prospectively enrolled. Parents chose Nembutal, chloral hydrate, or no preference. Thirty-eight infants received Nembutal (4-6 mg/kg) mixed with cherry syrup and 16 received chloral hydrate (50-100 mg/ kg). We recorded infant's acceptance of sedative, parental impression of infant's acceptance, time to sedation, time to discharge, adverse effects, parental preference of future sedative. RESULTS: Infant acceptance and parental impression were better for Nembutal (P < 0.0001). Fewer parents in the Nembutal group preferred another sedative (P = 0.05). There was a trend toward shorter time to discharge with Nembutal (P = 0.03). There were no adverse effects in either group. One infant failed to sedate with Nembutal. CONCLUSIONS: Compared with chloral hydrate, oral Nembutal has significantly better acceptance by infants and parents, equal effectiveness, and may result in a shorter time to discharge.

Malignant peritoneal mesothelioma in two pediatric patients: MR imaging findings.

Malignant mesothelioma is a rare tumor in childhood. We present two cases of malignant peritoneal mesothelioma in which contrast-enhanced, fat-saturated magnetic resonance (MR) imaging was used advantageously to detect peritoneal tumor involvement.

Improved MR imaging for patients with metallic implants.

Pediatric oncology patients with large metallic prostheses were imaged with one of two MR imaging techniques: 1) the "tilted view-angle" technique, 2) or a higher readout bandwidth technique. The tilted view-angle method uses an additional gradient in the slice selection direction during readout. The high bandwidth technique increases the readout bandwidth and shortens the echo time (TE). High bandwidth and short echo times were implemented in both T(1)-weighted (T(1)W) turbo spin echo and turbo short tau inversion recovery (STIR) sequences. Both imaging techniques reduced the size of metal-induced image artifacts. The tilted view-angle method reduced the artifact to a greater degree but had inherent shortcomings. The reformatted images were blurred and shifted. The area of interest was often moved outside of the field of view, unless parameters were adjusted on the basis of a pre-scan calculation. The high readout bandwidth, short echo technique required no special preparation and reduced metal artifacts without image blurring. The combination of high-bandwidth, shorter echo turbo STIR and T(1)W turbo spin echo sequences with subtraction of pre- from post-contrast images allowed effective fat suppression without local field inhomogeneity affects. This greatly improved our ability to evaluate suspected disease near metallic implants in pediatric cancer patients.

3D gadolinium-enhanced MRA: evaluation of hepatic vasculature in children with hepatoblastoma.

We used contrast-enhanced three-dimensional magnetic resonance angiography (3D MRA) modified for pediatric use to evaluate the hepatic vasculature prior to partial hepatectomy in five consecutive children with hepatoblastoma. Modifications included non-breath-hold technique in four of the five children who were sedated. The single breath-hold technique was performed in only one awake child. Scan delay times were based on contrast infusion time rather than total infusion time. The hepatic artery, portal vein, and inferior vena cava were identified in all patients. MRA findings were confirmed by conventional angiography in one patient and by surgery in all. Contrast-enhanced 3D MRA is a useful and rapid technique prior to partial hepatectomy in patients with hepatoblastoma.

Imaging findings of hemorrhagic cystitis in pediatric oncology patients.

In pediatric oncology patients, hemorrhagic cystitis may be a life-threatening complication of bone-marrow transplantation, chemotherapy, and/or radiation therapy. The inciting agent in urine can affect the entire urothelium from the renal collecting system to the bladder, and the severity of disease can vary. The radiologist often plays a key role in the diagnosis, follow-up, and occasionally the treatment of hemorrhagic cystitis and its complications. This review discusses the imaging findings in the kidneys and bladder in patients with hemorrhagic cystitis both before and after treatment for this disease. Findings on two-dimensional sonography, color Doppler and power Doppler sonography, computed tomography, magnetic resonance imaging, antegrade pyleography, and cystography are presented.

Budd-Chiari syndrome caused by Gaucher's disease.

We present a unique case of Budd-Chiari syndrome caused by Gaucher's disease. The diagnosis was based on Doppler sonography, magnetic resonance imaging, contrast-enhanced three-dimensional magnetic resonance angiography, standard venography, and venous pressure measurements and was confirmed histologically.

Direct translation of a protracted irinotecan schedule from a xenograft model to a phase I trial in children.

PURPOSE: In a preclinical model of neuroblastoma, administration of irinotecan daily 5 days per week for 2 consecutive weeks ([qd x 5] x 2) resulted in greater antitumor activity than did a single 5-day course with the same total dose. We evaluated this protracted schedule in children. PATIENTS AND METHODS: Twenty-three children with refractory solid tumors were enrolled onto a phase I study. Cohorts received irinotecan by 1-hour intravenous infusion at 20, 24, or 29 mg/m(2) (qd x 5) x 2 every 21 days. RESULTS: The 23 children (median age, 14.1 years; median prior regimens, two) received 84 courses. Predominant diagnoses were neuroblastoma (n = 5), osteosarcoma (n = 5), and rhabdomyosarcoma (n = 4). The dose-limiting toxicity was grade 3/4 diarrhea and/or abdominal cramps in six of 12 patients treated at 24 mg/m(2), despite aggressive use of loperamide. The maximum-tolerated dose (MTD) on this schedule was 20 mg/m(2)/d. Five patients had partial responses and 16 had disease stabilization. On day 1, the median systemic exposure to SN-38 (the active metabolite of irinotecan) at the MTD was 106 ng-h/mL (range, 41 to 421 ng-h/mL). CONCLUSION: This protracted schedule is well tolerated in children. The absence of significant myelosuppression and encouraging clinical responses suggest compellingly that irinotecan be further evaluated in children using the (qd x 5) x 2 schedule, beginning at a dose of 20 mg/m(2). These results imply that data obtained from xenograft models can be effectively integrated into the design of clinical trials.

Applications of 3D contrast-enhanced MR angiograpy in pediatric oncology.

Contrast-enhanced 3D MR angiography can be used for imaging of children. This technique can improve the delineation of the vasculature that is more anatomically familiar to surgeons. Here we illustrate the usefulness of contrast-enhanced 3D MR angiography in the diagnosis and follow-up of pediatric oncology patients.

Pilot study of noninvasive detection of venous occlusions from central venous access devices in children treated for acute lymphoblastic leukemia.

BACKGROUND: Survivors of childhood acute lymphocytic leukemia (ALL) are at risk of venous occlusion induced by central venous access devices (CVADs). A sensitive, noninvasive screening technique to identify the magnitude of this problem is needed. Ultrasound (US) cannot always adequately image the innominate veins or the superior vena cava. Magnetic resonance angiography (MRA) can be noninvasive and may be useful for screening these patients. OBJECTIVE: We examined the suitability of US and MRA to identify venous occlusion. MATERIALS AND METHODS: We used MRA and ultrasound to examine 11 pediatric patients previously treated for ALL. CVADs had been in place a median of 2.5 years (range, 0.4-2.8 years) and removed a median of 2.1 years (range, 0.6-2.9 years) previously. We also performed 2D time-of-flight magnetic resonance angiography (TOF MRA) on two healthy young adult women with no history of venous abnormality or CVAD use. RESULTS: MRA suggested central venous abnormalities in 8 of the 11 ALL survivors and in both healthy control subjects. US results were negative in all 11 survivors. CONCLUSION: Further investigation is warranted to develop a sensitive and specific noninvasive method for identifying venous occlusion caused by prior CVAD use. Such a method would allow prospective studies of this complication in pediatric ALL survivors.

Ewing's sarcoma recurrence vs radiation necrosis in dynamic contrast-enhanced MR imaging: a case report.

PURPOSE: We report a case of Ewing's sarcoma in the right distal femur in a 6-year-old male to demonstrate how dynamic contrast-enhanced magnetic resonance imaging (DEMRI) findings predicted histopathology. MATERIALS AND METHODS: DEMRI was performed at presentation and during and after completion of chemotherapy and radiation therapy. Histopathologic studies were done at presentation, at 77 weeks (20 weeks after a pathological fracture), and from the en bloc resection at 104 weeks. RESULTS: DEMRI predicted the early tumor response, absence of tumor recurrence, presence of necrosis and lack of fracture healing, confirmed by histopathology. CONCLUSION: DEMRI is a clinically useful tool in managing Ewing's sarcoma.

Lung abscess versus necrotizing pneumonia: implications for interventional therapy.

OBJECTIVE: To assess and contrast the role of interventional therapy for two types of cavitating pneumonias: lung abscess and necrotizing pneumonia. MATERIALS AND METHODS: We retrospectively reviewed the imaging, interventional therapy, and outcome of 14 children seen between February 1987 and January 1996 with lung abscess and 9 with necrotizing pneumonia. All children were treated with antibiotics prior to intervention. Pulmonary parenchymal fluid was percutaneously aspirated from ten lung abscesses and three necrotizing pneumonias. Percutaneous catheters drained five lung abscesses. Pleural drainage was performed for three lung abscesses and eight necrotizing pneumonias. RESULTS: All 14 children with lung abscesses had positive Gram stains of the pulmonary fluid; 13 cultures were positive. All 14 defervesced within 48 h of intervention. None developed a bronchopleural fistula. All nine necrotizing pneumonias were presumed to be sequelae of prior pneumonia. Streptococcus pneumoniae was the only organism as documented by pleural fluid latex fixation in three patients, gram stain in two, and culture in only one. Seven of these children developed pneumatoceles, five developed bronchopleural fistulae, and three required long-term chest tubes for persistent pneumothoraces. CONCLUSION: Aggressive interventional therapy can be diagnostic and therapeutic in the infected lung abscess. Interventional therapy can be harmful in postinfectious necrotizing pneumonia.