HIV-associated (non-thymic) intrathoracic lymphoepithelial cyst in a child.

An unusual case of a juxtabronchial lymphoepithelial cyst in an HIV-positive child with post-obstructive pneumonia is presented. The pathogenesis and similarity with parotid lymphoepithelial cysts is discussed.

Cystic dysplasia of the testis: sonographic diagnosis and differentiation from testicular microlithiasis.

Cystic dysplasia of the testis is an uncommon benign cause of an intratesticular mass in children. It is often associated with renal abnormalities, which reflects the close developmental association between the kidneys and testes. The diagnosis is usually suspected based on sonographic findings. We present a case of cystic dysplasia of the testis occurring in a boy with a multicystic dysplastic kidney, in whom the sonographic findings were initially misinterpreted as testicular microlithiasis.

Iron overload in reticuloendothelial systems of pediatric oncology patients who have undergone transfusions: MR observations.

OBJECTIVE: Pediatric oncology patients who undergo intensive chemotherapy develop anemia caused by myeloid suppression that necessitates transfusions that, in turn, cause iron deposition in the reticuloendothelial system. We describe MR imaging of iron overload in pediatric patients who underwent such chemotherapy and who have solid and hematologic tumors. MATERIALS AND METHODS: The MR appearance of the liver, spleen, and bone marrow was evaluated in 13 children with both solid (n = 10) and hematologic (n = 3) malignant lesions using known criteria for the presence of iron deposition. Findings were correlated with transfusional history, chemotherapeutic regimens, and ferritin levels. RESULTS: MR imaging obtained after chemotherapy and transfusional therapy revealed signs of iron deposition in the liver and spleen, particularly on T2-weighted images. Bone marrow signal intensity varied among patients. Pancreatic signal intensity was normal. Ferritin levels were elevated in all patients. CONCLUSION: Reticuloendothelial system iron deposition present in follow-up MR imaging of pediatric solid and hematologic malignant lesions reflected the intensity of the chemotherapeutic regimen, the degree of myeloid suppression, and the resultant transfusional requirements. Such iron deposition appeared to have no effect on cardiac, liver, or pancreatic function.

Lumbar gibbus in storage diseases and bone dysplasias.

OBJECTIVE: The objective of this study was to review the problem of lumbar gibbus in children with storage diseases and bone dysplasias utilizing plain films and MR imaging. MATERIALS AND METHODS: Clinical histories and radiographic images in five patients with storage diseases [four mucopolysaccharidosis (MPS) and one mucolipidosis] and two with achondroplasia were reviewed. The International Skeletal Dysplasia Registry (Los Angeles, Calif.), surveyed for all patients with lumbar gibbus and skeletal dysplasias, provided 12 additional cases. RESULTS: All patients had localized gibbus of the upper lumbar spine, characterized by anterior wedging and posterior displacement of the vertebrae at the apex of the curve, producing a beaked appearance. The curve, exaggerated in the sitting or standing position, was most severe in the two patients with MPS-IV (one of whom died). Both developed severe neurologic signs and symptoms requiring surgical intervention. In four patients, MR images demonstrated the apex of the curve to be at or below the conus. Two patients demonstrated anterior herniation of the intervertebral discs at the apex of the curve, though the signal intensity of the intervertebral discs was normal. CONCLUSION: Lumbar gibbus has important neurologic and orthopedic implications, and is most severe in patients with MPS. The etiology of the gibbus with vertebral beaking is multifactorial and includes poor truncal muscle tone, weight-bearing forces, growth disturbance and anterior disc herniation. The curve is generally at or below the conus. Neurologic complications are unusual, although orthopedic problems can arise. Due to their longer survival, patients with achondroplasia or Morquio's disease are more vulnerable to eventual gibbus-related musculoskeletal complications.

Dideoxyinosine-induced pancreatitis in human immunodeficiency virus-infected children.

Dideoxyinosine (ddI) is a widely used antiretroviral agent in treatment of HIV infection. Pancreatitis is a serious side effect. Two cases are reported, one with rapid development of a pseudocyst.

MR imaging of Baker cysts: association with internal derangement, effusion, and degenerative arthropathy.

PURPOSE: To determine the prevalence of Baker cyst in a general orthopedic population and its association with effusion, internal derangement, and degenerative arthropathy. MATERIALS AND METHODS: Reports of 400 knee magnetic resonance imaging examinations were reviewed. Presence of Baker cyst, effusion, internal derangement (meniscal and/or anterior cruciate ligament tears), medial collateral ligament injury, and degenerative arthropathy was recorded. Uni- and multivariate logistic regressions were used to evaluate associations between Baker cyst and these conditions. Probabilities of having a Baker cyst given these conditions were also calculated. RESULTS: No association was found between Baker cyst and anterior cruciate ligament tear or medial collateral ligament injury. There were significant associations (P < .001) with effusion, meniscal tear, and degenerative arthropathy. There were also significant associations (P < .01) for effusion, meniscal tear, and degenerative arthropathy, independent of one another. Probability of having Baker cyst given the presence of any one variable was .08-.10; any two variables, .19-.21; and all three variables, .38. CONCLUSION: The association between Baker cyst and joint effusion was confirmed. A relationship with meniscal tear and degenerative joint disease independent of effusion was also demonstrated. The probability of having a Baker cyst increases as the number of these associated conditions increases.

Intrasplenic masses of "preserved" functioning splenic tissue in sickle cell disease: correlation of imaging findings (CT, ultrasound, MRI, and nuclear scintigraphy).

PURPOSE: We studied six patients with sickle cell disease (SSD), five homozygous for sickle cell anemia and one with sickle beta-thalassemia, in whom rounded intrasplenic masses proved to be preserved functioning splenic tissue. MATERIALS AND METHODS: Available images including computed tomography, ultrasonography, bone scans (Tc-99m MDP), liver spleen scans (Tc-99m sulfur colloid), and MRI were evaluated. RESULTS: The masses were low density on CT (in an otherwise calcified spleen), hypoechoic relative to the echogenic spleen on US, and had the imaging characteristics of normal spleen on MRI. They failed to accumulate Tc-99m MDP but did demonstrate uptake of Tc-99m sulfur colloid. CONCLUSION: In a patient with SSD and intrasplenic masses, proper correlation of multiple imaging modalities will establish the diagnosis of functioning splenic tissue and avoid mistaken diagnosis of splenic abscess or infarction.

Benign adenomatous kidney neoplasms in children with polycythemia: imaging findings.

PURPOSE: To correlate pathologic, computed tomographic (CT), and ultrasound (US) characteristics of nephrogenic adenofibromas and embryonal adenomas (uncommon pediatric renal tumors) in children. MATERIALS AND METHODS: Medical records and imaging and pathologic findings were reviewed in three children (aged 6 1/2, 7, and 11 years) with adenomatous renal tumors and polycythemia. Specimens were reviewed at the National Wilms Tumor Study Pathology Center (Loma Linda, Calif). RESULTS: All tumors were smaller than 3 cm in greatest dimension. They were hyperechoic on US scans and had high attenuation on unenhanced CT scans. Two patients underwent nephrectomy for initial diagnosis of Wilms tumor. The third underwent local excision. At pathologic examination, embryonal-appearing adenomatous epithelial cells were found to form tubules and papillae with abundant psammomatous calcifications. Two masses were classified as embryonal adenomas and one as nephrogenic adenofibroma. CONCLUSION: Increased attenuation on CT scans and increased echogenicity on US scans of renal adenomatous tumors are distinctive findings that may reflect the presence of tubulopapillary structures and psammomatous calcifications.

Pneumothorax as the presenting sign of Pneumocystis carinii infection in an HIV-positive child with prior lymphocytic interstitial pneumonitis.

An HIV-positive child presented with a pneumothorax secondary to cavitary Pneumocystis carinii pneumonia (PCP). Lymphocytic interstitial pneumonitis had been evident on earlier radiographs but had resolved, concurrent with a decrease in her CD4 counts, before the radiographic changes of PCP became evident. As immune function declines in HIV-positive children, the chest radiograph may paradoxically clear. In such a setting, development of focal lung disease, including pneumothorax, may herald Pneumocystis carinii infection.

Deferoxamine-induced platyspondyly in hypertransfused thalassemic patients.

Deferoxamine chelation therapy (widely used to reduce iron overload in hypertransfused thalassemic patients) has been implicated in causing skeletal growth abnormalities (rachitic-like changes in the long bones and vertebral body flattening), particularly when used in early infancy and at high dose levels. Radiographs of seven hypertransfused and well-chelated patients with thalassemia were reviewed. For two patients, serial films of the spine from the early 1970s to the present revealed a sequence of changes in the vertebral bodies, beginning with normal bodies that became bulbous and subsequently flattened. These two patients had begun deferoxamine chelation therapy early in infancy. The bone changes, though slightly reminiscent of post-radiation changes, are milder and result in a final Scheuermann-like picture.

Congenitally short trachea and high carina with left mainstem bronchus compression by the ligamentum arteriosum.

We report a patient with congenitally short trachea (CST), defined as a decreased number of tracheal rings and high carina, who had respiratory distress and overaeration of the left lung secondary to extrinsic narrowing of the distal mainstem bronchus by ligamentum arteriosum compression.

Soft-tissue sarcomas: MR imaging findings after treatment in three pediatric patients.

PURPOSE: To characterize the skeletal and bone marrow magnetic resonance (MR) imaging changes during and after treatment of childhood soft-tissue tumors. MATERIALS AND METHODS: Three boys with soft-tissue sarcomas of the popliteal fossa underwent surgery, radiation therapy, and chemotherapy. Plain radiographic and MR imaging findings were correlated with the effect of treatment. RESULTS: After radiation therapy, MR images revealed findings that resembled those of rickets at sites of irradiation in the three patients. These findings included metaphyseal sclerosis, metaphyseal fraying, and epiphyseal plate widening. Bone marrow imaging changes were temporally related to therapy. During chemotherapy, reconversion to hematopoietic marrow was noted in nonirradiated areas in two patients, but after cessation of all treatment, these areas converted back to fatty marrow. Irradiated areas of bone marrow remained fatty throughout therapy in the three patients. CONCLUSION: Awareness of the MR imaging findings related to antineoplastic treatment of soft-tissue tumors is important to distinguish these changes from progression of primary disease.

MRI marrow observations in thalassemia: the effects of the primary disease, transfusional therapy, and chelation.

The magnetic resonance bone marrow patterns in thalassemia were evaluated to determine changes produced by transfusion and chelation therapy. Thirteen patients had T1- and T2-weighted images of the spine, pelvis and femurs. Three received no therapy (age range 2.5-3 years). Three were hypertransfused (transfused to maintain a hemoglobin greater than 10 g/dl) and not chelated because of age (age range 6 months-8 years). Seven were hypertransfused and chelated (age range 12-35 years). Signal characteristics of marrow were compared with those of surrounding muscle and fat. Fatty marrow (isointense with subcutaneous fat) was compared with red marrow (hypointense to fat and slightly hyperintense to muscle). Marrow hypointense to muscle was identified as iron deposition within red marrow. The untreated group demonstrated signal consistent with red marrow throughout the central and peripheral skeleton. Hypertransfused but not chelated patients demonstrated marked iron deposition in the central and peripheral skeleton. Hypertransfused and chelated patients demonstrated iron deposition in the central skeleton and a mixed appearance of marrow in the peripheral skeleton. The MR appearance of marrow in thalassemia is a reflection of the patient s transfusion and chelation therapy. Iron deposition occurs despite chelation therapy in sites of active red marrow. As red marrow retreats centrally with age, so does the pattern of iron deposition. The long-term biological effects of this iron deposition are unknown.

MR marrow signs of iron overload in transfusion-dependent patients with sickle cell disease.

Magnetic resonance (MR) marrow signal in the axial and appendicular skeleton of 13 transfusion-dependent and chelated pediatric patients with sickle cell anemia (SSD) was compared with marrow signal in six non-transfusion-dependent patients with SSD. Hepatic, pancreatic, and renal MR signal were also evaluated. Indication for hypertransfusion therapy was primarily prior history of stroke. Transfusion-dependent patients had evidence of iron deposition throughout the imaged marrow and the liver, despite deferoxamine chelation therapy. Non-transfusion-dependent patients did not demonstrate grossly apparent signs of iron overload. Red marrow restoration was present in the spine, pelvis, and long bones and, in some patients, within the epiphyses. Marrow edema secondary to vaso-occlusive crises was evident in the metaphyses and diaphyses of long bones in areas of both red and fatty marrow and was best seen using fat-saturated T2-weighted imaging techniques.

Midgut malfixation in patients with congenital diaphragmatic hernia: what is the risk of midgut volvulus?

Twenty-four patients with repaired diaphragmatic hernia had upper gastrointestinal series to assess the rotation and fixation of the bowel. A spectrum of rotational abnormalities was present in almost all patients, although those with repaired right-sided hernias demonstrated a more obvious anomaly of rotation than those with repaired left-sided hernias. No patient developed a midgut volvulus despite the presence of malfixation. Postoperative adhesions likely limit the occurrence of volvulus.

Systemic arterial collateral esophageal indentations in pseudotruncus arteriosus.

Barium esophagrams were obtained in two patients with respiratory problems whose underlying congenital heart disease was pseudotruncus arteriosus type I. The esophagrams revealed vascular indentations on the esophagus, one posteriorly, and the other anteriorly. Both types of indentations were secondary to aorto-pulmonary communicating arteries from the descending aorta.

Absence of lower extremity ossification centers in term infants with congenital syphilis.

Radiologic evaluation is valuable for confirmation of congenital syphilis. Bony abnormalities are thought to be secondary to active disease or a growth response of bone to systemic illness. Anteroposterior lower extremity radiographs of 85 euthyroid term infants (> or = 38 weeks' gestation; mean weight, 3244 gm; range, 1940-4380 gm) with presumptive congenital syphilis were evaluated for the presence of the distal femoral and proximal tibial secondary ossification centers and other bony abnormalities. Both proximal tibial and distal femoral ossification centers were absent in only 9 of 85 infants with syphilis; the proximal tibial center was absent in 26 of 85 (total 30.6%; 95% confidence limits 0.2 to 0.4). This observation is significant at the p < 0.01 level by chi-square analysis with use of historical controls. Periosteal new bone formation was seen in 2 of 85 infants. Metaphyseal lucent bands were present in 21 of 85 infants, 8 of whom also had absent lower extremity ossification centers. For comparison we reviewed lower extremity radiographs from 12 term infants without congenital syphilis. Ossification centers were absent in one growth-retarded infant, and metaphyseal lucent bands were found in one infant. Although standard texts report nearly universal ossification of the distal femoral epiphysis at term, we observed delayed skeletal maturation in 30.1% of term infants with congenital syphilis. We speculate that this delay may be reflective of systemic infection.