Pancreatic tumors in children and young adults with tuberous sclerosis complex

BACKGROUND

Pancreatic neuroendocrine tumors are not included in the diagnostic criteria for tuberous sclerosis complex, although an association has been described.

OBJECTIVE

To investigate the association of pancreatic neuroendocrine tumor in children and young adults with tuberous sclerosis complex and define MRI characteristics of the tumor.

MATERIALS AND METHODS

We retrospectively evaluated the abdominal MRI scans of 55 children and young adults with tuberous sclerosis complex for the presence of a pancreatic mass. The scans were performed over a period of 7 years to monitor renal pathology. We obtained each patient's clinical history and treatment protocol from the hospital's electronic medical records.

RESULTS

A solid pancreatic mass was identified in 5/55 (9%, 95% confidence interval [CI] 3-20%) patients (4 male) with a mean age of 12.6 years. Four of the lesions were located in the pancreatic tail and one in the pancreatic body. All of the lesions were solid, ovoid and well demarcated, with a mean diameter of 3.1 cm. The masses uniformly demonstrated T1 and T2 prolongation, but their diffusion behavior and post-contrast enhancement varied. The two surgically resected lesions were synaptophysin (+) non-functional pancreatic neuroendocrine tumors on pathology. Two of the patients who did not have surgery were treated with everolimus; one of the lesions has shown interval decrease in size and the other has remained stable.

CONCLUSION

Pancreatic tumor is relatively common in children and young adults with tuberous sclerosis complex.

An unusual presentation of subcutaneous granuloma annulare in association with juvenile-onset diabetes: case report and literature review

Subcutaneous granuloma annulare (SGA) is a rarely reported subtype of granuloma annulare that occurs almost exclusively in children. The etiology of these lesions is unknown, although a possible relationship to insulin-dependent diabetes mellitus (IDDM) has been proposed in the literature. Here we present an unusual case of SGA on the right forearm in a 3-year-old girl. Unlike the typical lesions noted on the extremities, on magnetic resonance imaging her lesions involved the subcutaneous tissue and adjacent muscles in multiple locations. Histopathologically, the case was consistent with SGA but was unusual in its distribution involving multiple muscles, a finding that has not been previously reported. Weeks after incisional biopsy, she was readmitted with diabetic ketoacidosis (DKA) secondary to IDDM. After treatment of her DKA and control of her glycemia, the forearm SGA vanished, which supported the pathologic diagnosis and alleviated our concerns secondary to the unusual distribution.

Bilateral renal masses in a 10-year-old girl with renal failure and urinary tract infection: the importance of functional imaging

Renal sonography is a routine step in the evaluation of new onset renal failure. When renal masses are discovered in this setting, functional imaging may be critical. We report a case of bilateral renal masses in a girl with urinary tract infection and renal insufficiency found to have vesicoureteral reflux. Renal scintigraphy revealed these masses to be the only remaining functional renal tissue, preventing potentially harmful resection.

Physical therapy alone compared with core decompression and physical therapy for femoral head osteonecrosis in sickle cell disease. Results of a multicenter study at a mean of three years after treatment

BACKGROUND

Osteonecrosis of the femoral head is a common complication in patients with sickle cell disease, and collapse of the femoral head occurs in 90% of patients within five years after the diagnosis of the osteonecrosis. However, the efficacy of hip core decompression to prevent the progression of osteonecrosis in these patients is still controversial.

METHODS

In a prospective multicenter study, we evaluated the safety of hip core decompression and compared the results of decompression and physical therapy with those of physical therapy alone for the treatment of osteonecrosis of the femoral head in patients with sickle cell disease. Forty-six patients (forty-six hips) with sickle cell disease and Steinberg Stage-I, II, or III osteonecrosis of the femoral head were randomized to one of two treatment arms: (1) hip core decompression followed by a physical therapy program or (2) a physical therapy program alone. Eight patients withdrew from the study, leaving thirty-eight who participated.

RESULTS

Seventeen patients (seventeen hips) underwent decompression combined with physical therapy, and no intraoperative or immediate postoperative complications occurred. Twenty-one patients (twenty-one hips) were treated with physical therapy alone. After a mean of three years, the hip survival rate was 82% in the group treated with decompression and physical therapy and 86% in the group treated with physical therapy alone. According to a modification of the Harris hip score, the mean clinical improvement was 18.1 points for the patients treated with hip core decompression and physical therapy compared with 15.7 points for those treated with physical therapy alone. With the numbers studied, the differences were not significant.

CONCLUSIONS

In this randomized prospective study, physical therapy alone appeared to be as effective as hip core decompression followed by physical therapy in improving hip function and postponing the need for additional surgical intervention at a mean of three years after treatment.

Are chest radiographs routinely necessary following thoracostomy tube removal?

OBJECTIVE

Chest radiographs (CXRs) are routinely obtained at many institutions in all pediatric patients following thoracostomy tube removal to search for pneumothorax (PTX). To aid in evaluating the necessity of this practice, this study investigates whether clinical signs and symptoms may be a sensitive predictor of PTX in such patients.

MATERIALS AND METHODS

Reports from CXRs obtained following chest tube removal in all pediatric patients (374 patients) who underwent cardiac surgery with chest tube placement over 1 year were reviewed. For cases with reported PTX, the PTX was quantified and chart review was performed to assess whether signs and symptoms of PTX preceded the CXR result.

RESULTS

Fifty-one of 374 children (13.6%) had a radiographically defined PTX within 6 h after thoracostomy tube removal. The PTX was large (>40%) in 2 children, moderate (20-40%) in 5 children, and small (<20%) in 44 children. Symptoms (dyspnea, tachypnea, respiratory distress) or signs (increased oxygen requirement, worsening arterial blood gas and/or hypotension) of respiratory distress were present at the time of the initial CXR in six of seven patients, who later underwent a major clinical intervention, and in one patient who did not. Major clinical interventions were performed in all patients with a large PTX, four of five patients with a moderate PTX, and one patient with a small PTX that later enlarged.

CONCLUSIONS

Clinical signs and symptoms identified nearly all patients with significant pneumothoraces. Future prospective investigations may examine reserving chest radiography following chest tube removal for select groups, such as symptomatic patients or those with tenuous cardiovascular status.

The "diaphanous" diaphragm: a radiographic sign seen after patch repair of congenital diaphragmatic hernia in neonates

OBJECTIVE

The purpose of this study was to describe the radiographic features and etiology of the "diaphanous" (translucent) diaphragm. This sign, which, to our knowledge, has not previously been described, is a transient phenomenon seen on chest radiographs, after surgical patch repair of congenital diaphragmatic hernia.

CONCLUSION

The diaphanous diaphragm is a consequence of air trapped in the porous polytetrafluoroethylene graft that creates an intragraft radiolucency apparent on postoperative chest radiographs obtained within the first 24 hr. This radiolucency is transient and gradually disappears over the first few postoperative days as the air is replaced by granulation tissue. This sign should be recognized and not mistaken for a persistent pneumothorax after repair of a congenital diaphragmatic hernia.

Focal fatty infiltration of the liver: analysis of prevalence and CT findings in children and young adults

OBJECTIVE

Focal fatty infiltration of the liver, a benign entity that can be confused with a malignant lesion, is well characterized in adults but not in children. The goal of this study was to determine by CT the prevalence and characteristics of focal fatty infiltration in children and young adults.

MATERIALS AND METHODS

We retrospectively analyzed 305 consecutive contrast-enhanced abdominal CT examinations of 218 children and young adults with no known liver disease, performed during 2 years at our institution, to identify focal fatty infiltration of the liver. The imaging criterion for focal fatty infiltration of the liver on helical CT was a geometric or ovoid low-attenuation area adjacent to the falciform ligament, gallbladder fossa, or porta hepatis. If a patient's findings met the CT criterion for focal fatty infiltration of the liver, all previous abdominal CT and MR imaging examinations performed for that patient were reviewed to assess the evolution of focal fatty infiltration of the liver.

RESULTS

Of 218 children and young adults, 20 (9.2%) met the CT criterion for focal fatty infiltration of the liver. In our population, focal fatty infiltration of the liver was identified only adjacent to the falciform ligament. The prevalence of focal fatty infiltration of the liver increased significantly with advancing age: 0% for ages 1 month-4 years; 7.3% for 5-9 years; 10.2% for 10-14 years, and 25.6% for 15-19 years (p < 0.0001).

CONCLUSION

Focal fatty infiltration of the liver was identified in 9.2% of patients in our population, and occurrence of this lesion in children increases significantly with advancing age. However, focal fatty infiltration of the liver is uncommon in infants and young children and should be a diagnosis of exclusion.

Pulmonary metastases at diagnosis of neuroblastoma in pediatric patients: CT findings and prognosis

OBJECTIVE

We undertook this study to determine the frequency, CT appearance, and clinical implications of the rare occurrence of pulmonary metastases among children presenting with neuroblastoma.

MATERIALS AND METHODS

A search of the Children's Cancer Group database revealed 21 of 567 children with reported lung metastases at original diagnosis of neuroblastoma. CT examinations available for 17 of these patients were analyzed retrospectively to determine if lung metastases were present, and if so, to characterize their radiographic features.

RESULTS

Seventeen (3%) of 567 patients presenting with Evans stage IV neuroblastoma had confirmed pulmonary metastases at diagnosis. All had metastases to at least one site other than the lungs. The most common CT appearance of pulmonary lesions was of up to five, small, bilateral, noncalcified nodules. In nine patients (53%), the pulmonary nodules initially resolved with treatment. In this cohort, six children developed progressive disease and died, and three are still alive. All eight children whose lung lesion did not completely respond to treatment died. Overall, children with pulmonary metastases had unfavorable Shimada histology, a higher association with amplification of the MYCN oncogene (p = 0.0002), and a decreased event-free survival (p < 0.001) when compared with all children with stage IV neuroblastoma without pulmonary metastases.

CONCLUSION

The search for neuroblastoma lung metastases, which occur more frequently than previously reported, is clinically important because their presence portends a poor prognosis.

Adynamic ileus after caesarean section mimicking intestinal obstruction: findings on abdominal radiographs

The purpose of this study was to determine the spectrum of findings and the frequency of apparent distal colonic obstruction on abdominal radiographs in women with obstructive symptoms following Caesarean section. A search of radiology files yielded 21 patients who had abdominal radiographs because of obstructive symptoms during the early post-operative period. The radiographs were reviewed retrospectively to characterize the bowel gas patterns in these patients. Medical records were also reviewed to determine the treatment and patient course. Abdominal radiographs showed findings suggestive of distal colonic obstruction in 15 patients (71%), small bowel obstruction in 2 (10%), adynamic ileus in 3 (14%) and a normal bowel gas pattern in 1 (5%). In all 15 patients with apparent distal colonic obstruction, there was minimal or no gas in the rectosigmoid, with an associated pelvic mass representing the enlarged post-partum uterus, which compressed the rectosigmoid and prevented it from filling with gas. All 21 patients had rapid clinical or radiographic improvement on conservative management, indicating a transient post-operative ileus. Radiologists should be aware of the limitations of abdominal plain radiographs following Caesarean section so that a post-operative ileus is not mistaken for a distal colonic obstruction and conservative measures can be undertaken to decompress the bowel until the ileus resolves.

Cartilaginous path of physeal fracture-separations: evaluation with MR imaging--an experimental study with histologic correlation in rabbits

PURPOSE

To define the transverse levels of intracartilaginous fractures by using magnetic resonance (MR) imaging and histologic analysis in experimental physeal fracture-separations.

MATERIALS AND METHODS

Physeal fracture-separations were evaluated with MR imaging in 28 distal femurs and 28 proximal tibias of 22 immature rabbits. The intraphyseal transverse level of injury was graded as juxtaepiphyseal (germinal or proliferative zones) or juxtametaphyseal (hypertrophic zone or zone of provisional calcification). Histologic sections from 23 specimens were studied to assess correlations. We assessed nonenhanced and gadolinium-enhanced T1-weighted, intermediate-weighted, T2-weighted, and spoiled gradient-recalled-echo T1-weighted images.

RESULTS

In all MR studies, the injury was visible as a cleft of signal intensity lower than the signal intensity of the physeal cartilage. Juxtaepiphyseal extension, seen in 18 (64%) of 28 fractures, was more frequent in the undulating central part of the distal femoral physis than in the flatter proximal tibial physis (P =.008). In 20 of 23 specimens, MR imaging and histologic findings had excellent correlation for the detection of fracture level and morphology.

CONCLUSION

The course and level of injury within the cartilage in physeal fracture-separations can be defined with MR imaging. Extension into the juxtaepiphyseal physis, a potential risk factor for growth arrest, is detectable with MR imaging; MR imaging and histologic findings correlate well.

Gating charge differences between two voltage-gated K+ channels are due to the specific charge content of their respective S4 regions

Voltage-gated ion channels that differ in their primary amino acid sequence in the putative voltage sensor, the S4 region, show distinct voltage-sensing characteristics. In this study, we directly compared two voltage-gated K+ channels, the mammalian RCK1 with the Drosophila Shab11, and correlated the specific amino acid content of their respective S4 regions with the distinct voltage-sensing properties they exhibit. We find that specific differences in the charge content of the S4 region are sufficient to account for the distinct gating valence of each channel. However, differences in residues inside the S4 region are not sufficient to account for each channel's characteristic voltage range of activation.