Role of CT in left-sided acute appendicitis: case report.

We present the computed tomographic findings in a case of left-sided acute appendicitis associated with midgut malrotation, which is a rare anomaly. The inflamed appendix was visualized as a tubular, fluid-filled, enhancing structure in the left lower quadrant. The entire colon was located in the left abdomen. The presence of a superior mesenteric vein rotation sign ascertained the presence of midgut malrotation. Computed tomography is useful not only in providing accurate diagnosis of left-sided appendicitis but also in detecting associated rotational anomalies, which may require separate surgical correction.

A case of head and neck kaposiform hemangioendothelioma simulating a malignancy on imaging.

Kaposiform hemangioendothelioma (KH) is an endothelial-derived spindle cell neoplasm often associated with Kasabach-Merritt syndrome. Most cases arise in infancy and childhood and are soft-tissue tumors. The tumor displays an appearance between capillary hemangioma and Kaposi's sarcoma. We report a case of KH in a 1-year-old girl involving a mass that showed abnormal enhancement of soft tissue superficial to the right temporal bone with partial destruction of the temporal bone, the temporomandibular joint, mandibular condyle, and occipital bone. The physical finding of a discolored mass led clinicians to consider a hemangiomatous lesion, whereas the radiological picture suggested a more aggressive diagnosis of rhabdomyosarcoma and aggressive fibromatosis.

Vertebral osteoid osteoma masquerading as a malignant bone or soft-tissue tumor on MRI.

PURPOSE: Four pediatric patients were sent to our institution with the diagnosis of soft-tissue/malignant bone tumor. In all cases an MRI was the initial study performed for neck or back pain. All were surgically proven to have an osteoid osteoma/osteoblastoma (OO) as a final diagnosis. The MRI findings are reviewed. METHODS: Four patients, three boys and one girl, ranging in age from 5 to 17 years, presented with symptoms of neck or back pain for 2 months to 2 years. Two had neurological findings. All patients underwent MRI. RESULTS: All MRIs demonstrated decreased T1 signal and increased T2 signal in the soft tissues and bone surrounding the lesions consistent with edema. Enhancement was observed in the adjacent soft tissues and in the lesion nidus retrospectively. CONCLUSION: Investigating neck or back pain with an initial MRI may lead to misleading diagnoses unless the radiologist is aware of the typical MRI appearance of vertebral osteoid osteoma.

Imaging of the brain in the HIV-positive child.

The prevalence of human immune-deficiency virus (HIV) infection around the world, coupled with increasing population movement, make it likely that many physicians will treat HIV-infected patients. New treatment protocols for the specific manifestations of acquired immune-deficiency syndrome (AIDS) make distinguishing the different neurological diseases of great importance. The pattern of disease in children differs from those of adults both in its distribution and etiology. This article encapsulates the salient aspects relating to the imaging of the brain in HIV-positive children, paying particular attention to recent advances and the different features of the various pathological conditions affecting the HIV-infected brain in children.

Radiologic features of pediatric thalamic and hypothalamic tumors.

A variety of histologic subtypes of tumor may affect the thalamus and the hypothalamus in the pediatric population. These tumors have radiologic features that are useful in predicting pathology. We discuss the radiologic findings of childhood thalamic and hypothalamic tumors and provide imaging examples.

Iatrogenic vertebral body compression fracture in a premature infant caused by extreme flexion during positioning for a lumbar puncture.

We present a case of vertebral body compression fracture that resulted from manual flexion of the spine of a premature infant in preparation for a lumbar puncture. Vertebral body fractures due to abnormal flexion in child abuse have been described. However, such fractures due to lumbar puncture-related positioning have not been reported. We present a pre-term infant who developed an L3 vertebral body compression fracture immediately after lumbar puncture.

Imaging features of Mycobacterium avium-intracellulare complex (MAC) in children with AIDS.

PURPOSE: The purpose of this paper was to review the imaging features of Mycobacterium avium-intracellulare complex (MAC) in 16 pediatric patients with human immunodeficiency virus (HIV). MATERIALS AND METHODS: We reviewed the pertinent clinical records of 16 children diagnosed with MAC between January 1990 and June 1998. These 16 cases were blood- or biopsy-proven to have MAC infection. Their plain films, abdominal, and chest CT scans were then reviewed and the findings were analyzed with reference to the few reported cases of children with MAC. RESULTS: Abdominal findings: all but one had retroperitoneal adenopathy, mesenteric adenopathy or both. Ten patients had hepatomegaly, while nine patients were found to have splenomegaly. Four patients had nonspecific thickened gallbladder wall, while intestinal wall thickening and thickened stomach folds were identified in six of ten patients. Necrotic, fluid-filled nodes were also found. Chest findings included mediastinal adenopathy, cystic/cavitary lesions and bronchiectasis. One patient developed a fistula between the mediastinal lymph nodes, esophagus, and bronchial tree. CONCLUSION: Pediatric patients with HIV who develop MAC infection may present with massive lymph node enlargement. This can occur not only in mesenteric and retroperitoneal nodes but also in hilar and posterior mediastinal nodes as well. As in MTB infection, these nodes can break down with development of fistulous tracts to both esophagus and adjacent lung. The major differential diagnostic consideration besides MTB is lymphoma.

Sialoblastoma and hepatoblastoma in a neonate.

We report a case of salivary gland neoplasm and associated hepatoblastoma. The sialoblastoma was diagnosed by prenatal sonography; however, the hepatoblastoma was imaged post-operatively. Prior knowledge could have prevented a subsequent operation, including the additional risks of repeat anesthesia. We suggest that if a sialoblastoma is in the differential diagnosis, then additional imaging may be indicated because of the possibility of associated lesions.

Histiocytosis presenting as a nasal mass.

The authors present a 1-year-old child who presented with an expansile enhancing mass of the nasal cavity that proved to be histiocytosis.

Punctate thymic calcification in infants with untreated Langerhans' cell histiocytosis: report of four new cases.

Four new cases of punctate thymic calcification in infants with untreated Langerhans' cell histiocytosis (LCH) are added to the four previously reported cases. All cases were shown on CT scans; plain films were rarely diagnostic. Pathologic correlation remains elusive since the usual biopsies of the LCH have been on skin or bone biopsies. A single prior pathologic study of the thymus in untreated LCH showed microscopic calcospherites. The thymic punctate calcific densities in patients with LCH may represent further accretion so that the calcospherites become macroscopic. The finding of such punctate calcific densities in an enlarged thymus of an infant with skin or bone or lung disease is strongly suggestive of LCH.

Renal manifestations of AIDS in children.

Renal abnormalities in pediatric AIDS patients are common. The most common renal abnormality is HIV nephropathy, which usually progresses to end-stage renal disease. Other disorders discussed are related to infection, malignancy, and medications. This review illustrates several of the imaging findings seen in the kidneys of these patients.

Macromastia in a newborn with Alagille syndrome.

We present a case of macromastia in a newborn with Alagille syndrome. A review of the literature failed to find any prior reports of this findings in Alagille syndrome patients. We propose that this patient's macromastia may be related to her liver failure and abnormal estrogen metabolism.

Ultrasonography of pylorospasm: findings may simulate hypertrophic pyloric stenosis.

We compared sonographic images and measurements of patients diagnosed as having hypertrophic pyloric stenosis and pylorospasm among infants with projectile vomiting. Thirty-seven patients with hypertrophic pyloric stenosis had an unchanged pyloric length (mean, 22.5 mm) and muscle wall thickness (mean, 5.3 mm). Thirty-four pylorospasm patients had considerable variability in measurement or image appearance during their studies. Means of their longest or largest measurements were 14.4 mm for pylorus length and 3.8 mm for muscle wall thickness. Among these, 53% had muscle wall thickness of 4 mm or greater and 18% had pyloric length of 18 mm or greater during some portion of their study. We concluded (after clinical follow-up study confirmed our ultrasonographic diagnoses) that pylorospasm may mimic hypertrophic pyloric stenosis for at least a portion of a sonographic study. Muscle wall thickness or pyloric length measurements may overlap those accepted as positive for hypertrophic pyloric stenosis. Image or measurement variability is an important clue for diagnosing pylorospasm.

Prenatal sonographic diagnosis of posterior urethral valves: identification of valves and thickening of the posterior urethral wall.

This report describes 2 heretofore unreported sonographic findings that may aid in the antenatal diagnosis of posterior urethral valves. Each of 2 fetuses showed a prominent or thickened posterior urethra and one or more bright echogenic lines representing valve tissue within a dilated and/or thickened posterior urethra. These findings helped solidify the antenatally suspected diagnosis of posterior urethral valves. The diagnosis was confirmed clinically and surgically during neonatal life. These 2 imaging findings may help in providing a more definitive antenatal diagnosis of posterior urethral valves and allow more expeditious therapy.

AIDS-related malignancies in pediatrics.

This article attempts to bring the reader up to date with the latest developments concerning AIDS-related malignancies in children. As these children live longer as a result of improved therapy, malignancies of the type described will become more common and wide-spread.

Simple renal cysts in children with AIDS.

Simple renal cysts are very uncommon among children. Of 50 children with AIDS that underwent computed tomography at our hospital, 4 had radiographically simple cysts. The incidence of simple renal cysts in this group of children is thus approximately 45 times that seen in normal children. To our knowledge, simple renal cysts have never been reported as a manifestation of AIDS in children. It is unknown whether or not these cysts are a manifestation of HIV nephropathy (HIVN), in which microcysts are seen pathologically. We suggest that simple renal cysts may be a finding compatible with the diagnosis of HIVN.

Diagnostic imaging in pediatric AIDS.

The manifestations of acquired immune deficiency syndrome (AIDS) in children are mainly secondary to opportunistic infection, lymphoproliferative diseases, and AIDS-related neoplasms. This article reviews the pathologic findings of various disorders afflicting children with AIDS and emphasizes the imaging of these disorders. Although many of the radiologic findings are not specific for a particular infection or neoplasm, the differential diagnostic possibilities for an abnormality can be narrowed down significantly with proper clinical correlation and knowledge of the imaging findings and pathologies specific to children with AIDS.

Renal carcinoma: bilateral breast metastases in a child.

Malignant metastasis to the breast, rare in adults, has occurred in children from hematologic malignancies and from neuroblastoma and rhabdomyosarcoma. We report a case of bilateral breast metastases in a 14-year-old girl with a prior nephrectomy for renal cell carcinoma; the breast masses were the first sign of recurrence.