Thoracic neuroblastoma: what is the best imaging modality for evaluating extent of disease?

BACKGROUND: Thoracic neuroblastoma accounts for 15% of all cases of neuroblastoma. A minority of children with thoracic neuroblastoma will have dumbbell tumors, i.e., intraspinal extension, but only half these patients will have neurologic signs or symptoms. HYPOTHESIS: MR imaging is the single best test to evaluate the extent of thoracic and spinal disease in thoracic neuroblastoma after the diagnosis of a mass is established on plain film. MATERIALS AND METHODS: A retrospective multi-institutional investigation over 7 years of all cases of thoracic neuroblastoma (n = 26) imaged with CT and/or MR were reviewed for detection of the extent of disease. The chest film, nuclear bone scan, and other imaging modalities were also reviewed. The surgical and histologic correlation in each case, as well as the patients' staging and outcome, were tabulated. RESULTS: The chest radiograph was 100% sensitive in suggesting the diagnosis. MR imaging was 100% sensitive in predicting enlarged lymph nodes, intraspinal extension, and chest wall involvement. CT was 88% sensitive for intraspinal extension but only 20% sensitive for lymph node enlargement. CT was 100% sensitive in detecting chest wall involvement. Direct comparison of CT and MR imaging in six cases revealed no difference in detection of enlarged lymph nodes or chest wall involvement. Neither test was able to detect remote disease, as noted by bone scan. CONCLUSION: The chest film is 100% sensitive in suggesting the diagnosis of thoracic neuroblastoma; MR imaging appears to be the single best test for detecting nodal involvement, intraspinal extension, and chest wall involvement.

Pyloric volume: an important factor in the surgeon's ability to palpate the pyloric "olive" in hypertrophic pyloric stenosis.

OBJECTIVE: The objective of this study was to determine whether the size of the pyloric mass is one of the factors in the surgeon's ability to palpate the pyloric "olive". MATERIALS AND METHODS: The ultrasonographic images and medical records of 60 infants with surgically confirmed hypertrophic pyloric stenosis (HPS) were reviewed. The pyloric diameter (PD) and pyloric length (PL) were measured and the pyloric volume (PV) was calculated using the equation PV = 1/4pi x (PD)2 x PL. Based on the pediatric surgeon's physical examination the infants were divided into two groups: those with and those without palpable pyloric masses. RESULTS: Infants with a palpable pyloric mass had an average pyloric volume of 3.33 +/- 1.76 mm3, which was statistically larger than those whose hypertrophied pylorus could not be palpated (average volume 2.59 +/- 2.07 mm3, P < 0.01). There was no statistically significant age difference between the two groups. CONCLUSION: Clinical skill of the examiner and other clinical aspects (patient cooperation, etc.) determine palpability of the pylorus in HPS. The size of the hypertrophied pylorus is also an important factor affecting the clinician's ability to palpate the pyloric mass.

Simultaneous occurrence of osteosarcoma and osteochondroma following treatment of neuroblastoma with chemotherapy, radiotherapy, and bone marrow transplantation.

Radiation-induced bone changes and second malignancies, as well as benign tumors, following bone marrow transplantation are being reported with increasing frequency. An osteosarcoma of the fourth right rib and an osteochondroma of the left scapula developed in a long-term survivor of abdominal neuroblastoma treated with chemotherapy, local radiation, and bone marrow transplantation. All these treatment modalities are known to induce neoplasia.

Sonographic diagnosis of acute appendicitis in children.

The authors performed graded compression abdominal ultrasound (US) examinations in children with suspected acute appendicitis, whose clinical presentation was atypical. Abdominal US examination results were 95% accurate, far exceeding that reported for other imaging modalities. The sensitivity was 86%, the specificity was 98%, and the positive and negative predictive values were 96% and 94%, respectively. A positive sonogram made the likelihood of acute appendicitis 50 times greater compared with the pretest clinical impression. In addition, the use of US permitted identification of other pathological conditions that manifest similar symptoms and signs. The authors conclude that, with proper experience, US can be extremely useful in assisting the surgeon to markedly decrease the number of unnecessary appendectomy procedures, without increasing the risk of perforation.

Marrow space imaging in Hodgkin's disease. MRI prior to biopsy for improved accuracy.

PURPOSE: Accurate staging of Hodgkin's disease is essential for choosing appropriate therapy. PATIENTS AND METHODS: A case of a 13-year-old boy with a history of Hodgkin's disease and negative iliac crest biopsies is presented. RESULTS: MRI-guided biopsy led to the accurate diagnosis of bone marrow involvement and a change in patient management. CONCLUSIONS: Magnetic resonance imaging has the potential to detect focal marrow involvement and therefore direct biopsy site.

Ovarian microcysts in girls with isolated premature thelarche.

We compared the frequency of ovarian microcysts in girls with premature thelarche (n = 27) to that in age-matched control subjects (n = 24). There was an increased prevalence of detectable ovarian microcysts in girls with premature thelarche. The presence or absence of cysts did not correlate with basal gonadotropin or estradiol levels.

Comparison of CT and MRI in the evaluation of therapeutic response in thoracic Hodgkin disease.

Current imaging modalities are accurate in establishing the diagnosis and extent of thoracic Hodgkin disease. After treatment, however, it is extremely difficult to differentiate potential residual active neoplastic disease from scar tissue, or identify early recurrence. We evaluated the contribution of MRI in the assessment of the response to treatment of thoracic Hodgkin disease in the assumption that scar formation would be characterized by low signal intensity in all pulse sequences, whereas active tumor should maintain a degree of high signal intensity on T2-weighted images. In 47 occasions (23 patients) both CT and MRI were able to identify correctly active disease, but had low specificity in confirming remission because of residual tissues masses. High signal intensity on T2-weighted MR images often persisted despite remission, probably because of edema, necrosis, granulation or other factors. MRI was somewhat more specific than CT and may be quite valuable to confirm remission in patients with residual masses that no longer appear hyperintense on T2 after treatment.

Paravertebral muscle metastases from primary tongue and nasopharyngeal carcinomas.

Skeletal muscle metastases most commonly originate from primary lung, breast, genito-urinary and gastro-intestinal tract malignancies. They have been seen to arise from head and neck tumours. However, the only primary tumours reported to metastasize to muscle from this region have been oesophageal and thyroid neoplasms. We present two cases with paravertebral muscle metastases from primary tongue and nasopharyngeal carcinomas.