Adrenocortical neoplasms in children: radiologic-pathologic correlation.

Primary neoplasms of the adrenal cortex are rare in children and differ significantly in epidemiology, clinical characteristics, and biologic features from their counterparts in adults. In children, the inclusive term adrenocortical neoplasm is applied because adrenal adenoma and adrenal carcinoma may be difficult to distinguish histopathologically. Pediatric adrenocortical neoplasms typically occur before 5 years of age, affect young girls more commonly than boys, and are associated with hemihypertrophy and Beckwith-Wiedemann and Li-Fraumeni syndromes. Most children with an adrenocortical neoplasm present with signs and symptoms of endocrine abnormality, including virilization and Cushing syndrome. Cross-sectional imaging studies typically demonstrate a large, circumscribed, predominantly solid suprarenal mass with variable heterogeneity due to hemorrhage and necrosis. Calcification is not uncommon. Local invasion and metastases to the lungs, liver, and regional lymph nodes may be present at diagnosis. When friable tumor thrombus extends into the inferior vena cava, it poses a high risk of pulmonary embolization. The finding of increased retroperitoneal fat due to hypercortisolism on computed tomographic and magnetic resonance images of children with an adrenal mass favors the diagnosis of adrenocortical neoplasm. Surgical resection is the mainstay of therapy, with chemotherapy used for patients with metastases or persistent elevated hormone levels following surgery. Patients younger than 5 years with aggressive adrenocortical neoplasms fare better than older children.

Nephrogenic rests, nephroblastomatosis, and associated lesions of the kidney.

The fetal kidney is formed by the development of nephrons from fetal metanephric blastema surrounding the ureteric bud. The fetal renal tissue matures into normal renal parenchyma during gestation, but, occasionally, fetal tissue persists into infancy as microscopic foci called nephrogenic rests. Nephrogenic rests are found in approximately 1% of infant kidneys at autopsy. Nephrogenic rests are associated with an increased risk of Wilms tumor, and it is theorized that nephrogenic rests undergo neoplastic change into Wilms tumor. Fortunately, this transformation occurs in less than 1% of young children with nephrogenic rests. Nephrogenic rests are associated with many syndromes, including Beckwith-Wiedemann syndrome, hemihypertrophy, and sporadic aniridia. Children with identifiable syndromes, once diagnosed, should be screened for the development of Wilms tumor. Nephrogenic rests are associated with other lesions such as multilocular cystic nephroma and multicystic dysplasia, usually without malignant complications.

Lung disease in premature neonates: impact of new treatments and technologies.

Advances in perinatal medicine and neonatology have dramatically changed clinical outcomes for premature neonates and have ushered in a new era of radiological complexity. "Portable" chest radiographs continue to be the mainstay in diagnostic imaging of fragile newborns, but radiologists may be confronted with new and unexpected radiological expressions of once-familiar disease processes. Familiarity with the radiological impact of emerging treatments in premature neonates is essential for accurate film interpretation.

Pulmonary inflammatory pseudotumor: radiologic features.

PURPOSE: To define the radiologic features of pulmonary inflammatory pseudotumor. MATERIALS AND METHODS: Between 1966 and 1994, 61 cases of pulmonary inflammatory pseudotumor involved 36 male and 25 female patients (age range, 17 months to 61 years; mean, 28 years). Clinical presentation, pathologic features, and radiologic findings were noted. RESULTS: At radiography, 52 patients had solitary peripheral nodules or masses, and extraparenchymal involvement--including hilar, mediastinal, and airway invasion--was found in 11. At computed tomography, 12 lesions were of heterogeneous attenuation and five, homogeneous. At T1-weighted magnetic resonance imaging, five lesions had intermediate signal intensity; of two lesions studied with T2-weighted imaging, two had high signal intensity; and the one lesion studied with gadolinium-enhanced imaging had diffuse enhancement. CONCLUSION: Pulmonary inflammatory pseudotumor was typically a solitary, peripheral, sharply circumscribed mass with an anatomic bias for the lower lobes. Local invasion and primary involvement of the mediastinum and hilar structures were unusual manifestations.

From the archives of the AFIP. Genitourinary rhabdomyosarcoma in children: radiologic-pathologic correlation.

Rhabdomyosarcoma is the most common tumor of the lower genitourinary tract in children in the first 2 decades of life. Most cases of genitourinary rhabdomyosarcoma are of the embryonal histologic subtype and include tumors of the bladder, prostate, testes and paratesticular sites, penis, perineum, vagina, and uterus. The natural history, pattern of metastatic spread, treatment, and prognosis of childhood rhabdomyosarcoma vary with the anatomic site of the lesion. In children with rhabdomyosarcoma of the bladder or prostate, presenting signs and symptoms include urinary or fecal retention, dysuria, urinary tract infection, and hematuria. Paratesticular rhabdomyosarcoma produces painless scrotal swelling, which may be ignored until the tumor has reached a large size. Vaginal tumors may manifest as a prolapsing mass in the introitus. Radiologic studies of children with genitourinary rhabdomyosarcoma reflect the nonspecific gross features of the tumor, which may be ill defined with infiltrative margins or well circumscribed by a pseudocapsule of compressed tissue. The botryoid variant of embryonal rhabdomyosarcoma results when submucosal tumor produces a polypoid mass resembling a cluster of grapes within a hollow structure. Botryoid morphology is characteristic, but not specific, for rhabdomyosarcoma within the vagina or urinary bladder, since yolk sac tumor and "tumoral" cystitis may have a similar appearance. Invasion of adjacent structures by the primary tumor may make the precise anatomic origin of genitourinary rhabdomyosarcoma difficult to determine on cross-sectional images. Recent refinements in multidisciplinary therapeutic regimens combining chemotherapy, radiation therapy, and surgery have dramatically improved outcome for children with genitourinary rhabdomyosarcoma. Diagnostic imaging plays an important role in monitoring response to therapy.

Rhabdoid tumor of the kidney in children: a comparative study of 21 cases.

OBJECTIVE: Rhabdoid tumor of the kidney (RTK) is unique among childhood renal neoplasms in its frequent association with primary or metastatic CNS lesions. Previous reports suggest that RTK has characteristic CT features. It has been proposed that if CT could accurately predict the correct diagnosis of RTK preoperatively, then imaging protocols might be modified during the examination to include imaging of the brain. We wished to determine if RTK could be reliably distinguished from other renal neoplasms of early childhood. MATERIALS AND METHODS: We retrospectively reviewed clinical, radiologic, and pathologic records of 21 patients with RTK. The study group included 13 males and eight females who were newborn to 36 months old (mean, 11 months). The study group was compared with 153 patients who were 3 years old or younger and who had solid renal masses. From the comparison group a subset of 54 patients 1 year old and younger was also selected for comparison with 13 (62%) of the 21 patients in the study group who were 1 year old or younger. Both comparison groups consisted of patients whose case material was consecutively added to the radiologic pathology archives at our institution. Diagnoses of the group of 153 patients were Wilms' tumor (n = 93), mesoblastic nephroma (n = 44), clear cell sarcoma of the kidney (n = 12), renal cell carcinoma (n = 3), and undifferentiated sarcoma (n = 1). RESULTS: A prominent eccentric crescent with the attenuation of fluid, representing sub-capsular renal hemorrhage or peripheral tumor necrosis adjacent to tumor lobules, was revealed on CT scans in 15 (71%) of the 21 patients with RTK and in seven (54%) of the 13 patients with RTK who were 1 year old or younger. Nineteen (12%) of 153 patients in the larger comparison group, representing patients with all tumor types, had CT features identical to those of the RTK group, including six (4%) patients with pathologic confirmation of sub-capsular renal hematomas. Six (11%) of the 54 comparison patients 1 year old and younger had CT features identical to those of the RTK group, and all proved to have mesoblastic nephroma. Associated CNS lesions were seen on CT or MR imaging in 11 (52%) of the 21 patients with RTK but none was seen in the comparison group of patients. CONCLUSION: On CT, a peripheral crescent with the attenuation of fluid is characteristic of RTK. However, 12% of renal neoplasms that occur more commonly than RTK in children had CT findings indistinguishable from those of RTK. Because the prevalence of RTK is relatively low, and because the CT findings are not pathognomonic, a renal mass seen on CT in a child is unlikely to represent RTK regardless of its CT features. We therefore conclude that the routine addition of CT of the brain for pediatric patients with renal masses that show a peripheral crescent of fluid attenuation is not justified. Supplemental imaging of the brain should be based on clinical findings or tissue diagnosis.

Gastrointestinal manifestations of cystic fibrosis: radiologic-pathologic correlation.

Cystic fibrosis (CF), the most common lethal autosomal recessive disease in white populations, is characterized by dysfunctional chloride ion transport across epithelial surfaces. Although recurrent pulmonary infections and pulmonary insufficiency are the principal causes of morbidity and death, gastrointestinal symptoms commonly precede the pulmonary findings and may suggest the diagnosis in infants and young children. The protean gastrointestinal manifestations of CF result primarily from abnormally viscous luminal secretions within hollow viscera and the ducts of solid organs. Bowel obstruction may be present at birth due to meconium ileus or meconium plug syndrome. Complications of meconium ileus include volvulus, small bowel atresia, perforation, and meconium peritonitis with abdominal calcifications. Older children with CF may present with bowel obstruction due to distal intestinal obstruction syndrome or colonic stricture, and tenacious intestinal residue may serve as a lead point for intussusception or cause recurrent rectal prolapse. Radiologic studies often demonstrate thickened intestinal mucosal folds in older children and uncommonly show colonic pneumatosis, peptic esophageal stricture due to gastroesophageal reflux, and duodenal ulcer. Appendicitis due to inspissated secretions is uncommon. Obstruction of ducts and ductules produces exocrine pancreatic insufficiency, pancreatitis, cholestasis, cholelithiasis, and cirrhosis with portal hypertension. On imaging studies, the pancreas is commonly small and largely replaced by fat, sometimes displays calcifications, and is rarely replaced by macrocysts. Radiologic features of hepatobiliary disease include an enlarged radiolucent liver from steatosis, gallstones, a shrunken nodular liver, splenomegaly, and portosystemic collateral vessels. With the improved survival of CF patients, an increased risk for developing gastrointestinal carcinomas has been established, many occurring as early as the 3rd decade.

Inverted Meckel diverticulum: clinical, radiologic, and pathologic findings.

PURPOSE: To determine the clinical, radiologic, and pathologic findings of inverted Meckel diverticulum by retrospectively reviewing a large series of cases. MATERIALS AND METHODS: Among 84 cases of Meckel diverticulum, 18 (21%) were found at surgery to be inverted into the lumen of the bowel. Thirteen of these 18 (72%) cases were associated with small bowel intussusception and five (28%) were not. RESULTS: All 18 patients (median age at time of diagnosis, 32 years) were symptomatic, but the symptoms were subacute or chronic in 14 (78%). At barium examination in 15 cases, inverted diverticulum was depicted in 10 (67%) as a solitary, elongated, smoothly marginated, often club-shaped intraluminal mass in the distal ileum. At computed tomography (CT) in three cases, a central area of fat attenuation was surrounded by a thick collar of soft-tissue attenuation. At ultrasound (US) in two cases, a target-like mass contained a central area of increased echogenicity. At pathologic examination in all cases, the inverted sac contained mesenteric fat. CONCLUSION: Inverted Meckel diverticulum occurs more commonly than previously recognized and is associated with characteristic findings at barium examination, CT, and US.

Multilocular cystic renal tumor in children: radiologic-pathologic correlation.

Multilocular cystic renal tumor is a term that encompasses two histologically distinct but grossly indistinguishable lesions: cystic nephroma and cystic partially differentiated nephroblastoma (CPDN). Cystic nephroma is a segmental, purely cystic mass characterized by multiple septations composed entirely of differentiated tissues, without blastemal elements. CPDN is also a multiloculated lesion without nodular solid components, but its septa contain embryonal cells. Multilocular cystic tumors primarily affect boys during early childhood, with a substantial number of the lesions containing blastema (CPDN), and adult women, with lesions that more commonly lack septal blastema (cystic) nephroma). As a rule, nephrectomy is curative and the clinical course benign, but CPDN may recur locally. Although cystic nephroma and CPDN cannot be distinguished radiologically, failure to do so has no practical impact on management, since all of these tumors are surgically removed. However, the differential diagnosis includes other pediatric cystic renal masses that may require different treatment stratagems: Wilms tumor with cyst formation due to hemorrhage and necrosis, cystic clear cell sarcoma, cystic mesoblastic nephroma, cystic renal cell carcinoma, multicystic dysplastic kidney, and segmental multicystic dysplasia in a duplicated renal collecting system.

Pulmonary tuberculosis in children.

TB is no longer the scourge it once was, but it remains an important cause of morbidity and mortality worldwide. Fueled by increasing poverty, homelessness, immigration, drug abuse, declining prevention programs, and the HIV epidemic, its incidence in the United States has increased dramatically. The complex natural history of pulmonary TB in children is reflected in its varied radiographic manifestations. Strict distinction between "adult" and "childhood" patterns of TB should be avoided (Fig 16). In general, adenopathy is the footprint of childhood primary pulmonary TB, with or without a readily apparent primary parenchymal focus or pleural effusion. Infants and young children are more likely to present with adenopathy only than their older counterparts. The pediatric tracheobronchial tree is particularly susceptible to compression by surrounding nodes, producing segmental atelectasis, or less commonly, obstructive emphysema. Self-limited lymphohematogenous dissemination is the rule, but actual miliary disease is the exception. Pediatric postprimary TB, when it occurs, is usually observed in adolescents. It is characterized by parenchymal disease with an anatomic bias for the upper lung zones. Proper image interpretation is inextricably dependent on an understanding of the pathogenesis of this fascinating and often baffling illness whose appearance widely varies depending on host age and immunity as well as the virulence of the organism itself.

Three-dimensional CT diagnosis of myositis ossificans of the sacrospinous ligament.

We present the case of a 4-year-old female with a complex fracture of the left hemipelvis who, on follow-up CT imaging, developed new ossific densities within the peripelvic soft tissues of the contralateral side. Three-dimensional surface reformations of the pelvis demonstrated myositis ossificans along the course of the right sacrospinous ligament, thus elucidating unsuspected ligamentous injury and implying prior instability.

Multiple coarctations of the pulmonary artery: scintigraphic appearance.

A case of angiography-proven multiple coarctations of the pulmonary arteries is presented. The patient had a history of long-standing exertional dyspnea and intranasal cocaine use. A chest radiograph suggested oligemia in the left lung and enlargement of the right pulmonary artery, prompting ventilation and perfusion radionuclide lung imaging. The combined scintigraphic and radiographic findings were indistinguishable from those caused by pulmonary emboli. Although rare, this entity should be included in the differential diagnosis of multiple unmatched perfusion defects on pulmonary ventilation-perfusion studies.