An evidence-based evaluation of percutaneous vertebroplasty.

BACKGROUND INFORMATION: Percutaneous vertebroplasty is a therapeutic, interventional radiologic procedure that involves injection of bone cement into a cervical, thoracic, or lumbar vertebral body lesion for the relief of pain and the strengthening of bone. This procedure only recently has been introduced, and is being used for patients with lytic lesions due to bone metastases, aggressive hemangiomas, or multiple myeloma, and for patients who have medically intractable debilitating pain resulting from osteoporotic vertebral collapse. FINDINGS: Results from two uncontrolled prospective studies and several case series reports, including one with 187 patients, indicate that percutaneous vertebroplasty can produce significant pain relief and increase mobility in 70 percent to 80 percent of patients with osteolytic lesions in the vertebrae from hemangiomas, metastases, or myeloma, or with osteoporotic compression fractures. In these reports, pain relief was apparent within one to two days after injection, and persisted for at least several months up to several years. While experimental studies and preliminary clinical results suggest that percutaneous vertebroplasty can also strengthen the vertebral bodies and increase mobility, it remains to be proven whether this procedure can prevent additional fractures in the injected vertebrae. In addition, the duration of effect is not known; there were no long-term follow-up data on most of these patients, and these data may be difficult to obtain and interpret in patients with an underlying malignant process, because disease progression may confound evaluation of the treatment effect. Complications were relatively rare, although some studies reported a high incidence of clinically insignificant leakage of bone cement into the paravertebral tissues. In a few cases, the leakage of polymer caused compression of spinal nerve roots or neuralgia. Several instances of pulmonary embolism were also reported. Although patient selection criteria have not been definitely established, percutaneous vertebroplasty is considered appropriate treatment for patients with vertebral lesions resulting from osteolytic metastasis and myeloma, hemangioma, and painful osteoporotic compression fractures if the following criteria have been met: o Severe debilitating pain or loss of mobility that cannot be relieved by correct medical therapy. o Other causes of pain, such as herniated intervertebral disk have been ruled out by computed tomography or magnetic resonance imaging. o The affected vertebra has not been extensively destroyed and is at least one third of its original height. o Radiation therapy or concurrent surgical interventions, such as laminectomy, may also be required in patients with compression of the spinal cord due to ingrowth of a tumor. CONCLUSIONS: Percutaneous vertebroplasty has only recently been introduced as a treatment for osteolytic lesions and osteoporotic compression fractures of the vertebrae, but early results are promising. Up to 80 percent of patients with pain unresponsive to correct medical treatment experience a significant degree of pain relief, and few serious complications have been reported. However, relatively few patients have undergone this procedure, and there are no data from controlled clinical trials or from studies with long-term follow-up. At the present time this procedure is still in the investigational stages, but may be appropriate for patients with no other reasonable options for medical treatment.

Helical CT of renal masses: the value of delayed scans.

OBJECTIVE: Routine scanning techniques used for helical CT of the abdomen result in dense cortical opacification of the kidney, whereas the medulla and collecting system are not well opacified, which potentially compromises detection of renal masses. The purpose of this retrospective study was to determine if additional delayed views (taken approximately 2-4 min after the start of injection of contrast material) are necessary for the detection and characterization of renal masses. MATERIALS AND METHODS: Early (60-70 sec after the start of the injection of contrast material) and delayed scans of 40 patients with suspected renal masses were blindly evaluated by two observers. The patients harbored a total of 187 renal masses (including 62 solid masses). Each region of the kidney (upper, middle, and lower pole) was scored for the presence of a mass. Scoring was done as a binary decision and also as a five-point confidence score for receiver operating characteristic analysis. RESULTS: We found 97 regions that contained renal masses and 114 regions that did not. Receiver operating characteristic analysis revealed the observers to have significantly greater confidence in detection of renal masses on the delayed scans. The binary data showed the two observers to have a sensitivity of 97% for delayed scans versus 77% (p = .0002) and 89% (p = .027), respectively, for the early scans. For the first observer, early and delayed scans were of equal specificity, but for the second observer, the delayed scans yielded greater specificity (94% versus 85%, p = .024). On the early scans, both observers were significantly more likely to miss a neoplastic lesion than a nonneoplastic lesion. The less experienced of the two observers also tended to have greater difficulty in characterizing the lesions on the early scans. CONCLUSION: Because of the significant risk of missing a renal mass, especially a neoplasm, on early cortical-phase scans, additional delayed scans appear justified when a renal mass is suspected on the basis of other imaging tests or clinical history.

Management of locally advanced prostate cancer.

The staging and treatment of prostate cancer are complex, particularly in patients with clinical disease that has advanced locally beyond the confines of the gland. Management choices are made more difficult by a paucity of quality randomized and controlled studies. Staging has traditionally relied on digital rectal examination, which is now being augmented by improved noninvasive radiologic studies. Radiation is the most common form of treatment today, and newer techniques are being examined and compared to external-beam therapy. Surgical intervention as monotherapy has failed to show a survival advantage. Current approaches treatment appear to be evolving toward combination therapies, potentially incorporating hormonal manipulation. Patients with locally advanced disease should be encouraged to enter prospective clinical trials.

Primary extragonadal germ cell tumors of the retroperitoneum: differentiation of primary and secondary tumors.

Primary extragonadal germ cell tumors (EGCTs) of the retroperitoneum are rarely encountered. In most cases, they arise from remnants of the genital ridge, whereas the majority of retroperitoneal germ cell tumors are metastases from primary testicular tumors. Differentiating between these primary and secondary tumors can be difficult because gonadal germ cell tumors can regress or develop slowly. Careful examination of the testes with ultrasound (US) is crucial for this determination, but asynchronous or metachronous lesions in both the testes and retroperitoneum can occur. Symptoms are often nonspecific, and diagnosis is frequently delayed. Serum markers such as beta-human chorionic gonadotropin and alpha-fetoprotein are often helpful in the diagnosis and follow-up of these tumors. Imaging techniques such as US and computed tomography play a major role in the localization and differentiation of primary and secondary retroperitoneal EGCTs. Treatment of EGCTs usually requires a combination of surgery, irradiation, and chemotherapy.

Renal oncocytoma and carcinoma: failure of differentiation with CT.

The authors studied the hypothesis that oncocytoma and adenocarcinoma of the kidney can be differentiated with computed tomographic (CT) criteria and that differences would become more apparent as tumors enlarged. On contrast material-enhanced scans, homogeneous attenuation throughout the tumor and a central, sharply marginated, stellate area of low attenuation were considered predictors of oncocytoma. Any area of decreased attenuation in the tumor except for a stellate, central area was used as a predictor of adenocarcinoma. Among oncocytomas larger than 3 cm in diameter, 67% exhibited the criteria for oncocytoma and 33% met the criterion for adenocarcinoma; among smaller oncocytomas, the respective results were 82% and 18%. Among adenocarcinomas larger than 3 cm in diameter, 84% fulfilled the criterion for malignancy and 16% were incorrectly predicted to be oncocytomas; among smaller adenocarcinomas, the respective results were 58% and 42%. The authors conclude that the CT criteria used are poor predictors of the diagnosis of oncocytoma or adenocarcinoma regardless of tumor size.

The natural history of renal lesions in von Hippel-Lindau disease: a serial CT study in 28 patients.

OBJECTIVE: Von Hippel-Lindau disease is a multisystem disorder predisposing to renal cysts and cancer. The growth and development of these renal lesions have not been documented previously. We reviewed serial CT scans to determine the rates and patterns of growth of renal lesions associated with von Hippel-Lindau disease. SUBJECTS AND METHODS: Twenty-eight patients with von Hippel-Lindau disease and renal involvement, including the spectrum from simple cysts to solid masses, had follow-up examinations for at least 1 year (mean, 2.4 years; range, 1-12 years) with serial contrast-enhanced abdominal CT. Renal lesions were measured and characterized. Surgical correlation was available in 12 patients. RESULTS: Two hundred twenty-eight lesions (eight lesions per patient) were detected. On the basis of their CT appearance, 168 lesions (74%) were classified as cysts, 18 (8%) as cysts with solid components, and 42 (18%) as solid masses. Among 12 patients with pathologic confirmation, the solid components of cystic lesions and solid lesions almost always contained renal carcinoma. The majority of cysts remained the same size (71%) or enlarged (20%); 9% became smaller or entirely involuted during the follow-up period. Although it is generally presumed that renal cysts are precursors to cancers, the transformation of a simple cyst to a solid lesion was observed in only two patients. Among the 42 solid lesions, all but two enlarged with time, with a mean doubling time of 10 months. CONCLUSION: The renal lesions associated with von Hippel-Lindau disease exhibited wide differences in growth. The majority of renal cysts grew slowly but some involuted. Transition to solid renal cancer was rare among cysts. Complex cystic and solid lesions contained neoplastic tissue that uniformly enlarged. These data may be used to help predict the progression of renal lesions in von Hippel-Lindau disease.

From the archives of the AFIP. Leiomyosarcoma of the retroperitoneum and inferior vena cava: radiologic-pathologic correlation.

Leiomyosarcoma is the second most common primary retroperitoneal tumor in adults. Retroperitoneal leiomyosarcoma exhibits three major growth patterns: (a) completely extravascular (extraluminal) (62% of cases), (b) completely intravascular (intraluminal) (5% of cases), and (c) extra- and intraluminal (33% of cases). The usual clinical manifestation is a large abdominal mass. Intraluminal leiomyosarcoma may be accompanied by symptoms referable to venous thrombosis. The variable gross features and potential for intravascular extension result in various radiologic appearances, the most common being a large, partially necrotic soft-tissue mass in the retroperitoneum with or without extension into the inferior vena cava. Computed tomography and magnetic resonance imaging typically show a nonfatty, necrotic retroperitoneal mass and a vascular component when it is present. Ultrasound and angiography may also be useful, especially if vascular involvement is suspected from other imaging studies. Treatment of choice is surgical excision, which is frequently impossible due to the invasiveness of the tumor. Prognosis is related to extent of invasion and the adequacy of resection. Long-term prognosis is poor, and most patients die of local recurrence or distant metastasis.

MR imaging of the portal venous system: value of gradient-echo imaging as an adjunct to spin-echo imaging.

We evaluated the use of gradient-echo (GRE) as an adjunct to spin-echo (SE) MR imaging of the portal venous system. GRE imaging was performed in 31 subjects, 15 normal volunteers and 16 patients with documented portal venous disease (15 cases) or suspected disease (one case). Eight of 16 patients had venous thrombosis, five had focal thrombus, and three had complete occlusion. Six patients had extrinsic venous compression by tumor. Of the two other patients, one had an arteriovenous fistula and the other a falsely positive angiogram, suggesting portal vein occlusion. In normal subjects, GRE scans had excellent visualization of the portal venous system with high intravascular signal compared with surrounding tissues. Nine (60%) of 15 normal subjects and three patients had an artifact consisting of a curvilinear area of decreased signal that could mimic clot. In three of five patients with focal thrombus, clot was identified on GRE but not on SE images. In all three patients with occlusion, SE and GRE images demonstrated similar findings. In five of the six patients with extrinsic venous compression by tumor, SE and GRE studies showed similar findings. Of the two patients, an arteriovenous fistula was seen on GRE MR in one, and in the other, patency of the left portal vein was seen on SE and GRE images after angiography had suggested portal vein occlusion. Collateral vessels were seen in nine of 16 patients. In five of nine cases, GRE MR demonstrated more extensive collaterals than did SE MR. In summary, GRE MR provides a useful adjunct to standard SE MR imaging. Benefits include high contrast between vascular structures and surrounding tissues, reduced motion artifact, and rapid scanning within a breath-hold.

From the Archives of the AFIP. Xanthogranulomatous pyelonephritis.

Xanthogranulomatous pyelonephritis is a form of chronic infection of the kidney and surrounding tissues characterized by destruction and replacement of renal parenchyma by lipid-laden macrophages. Gross pathologic features include massive renal enlargement, lithiasis, peripelvic fibrosis, hydronephrosis, and lobulated yellow masses replacing renal parenchyma. Typically, the disease is diffuse and has characteristic imaging features. Less commonly, the process is focal and is difficult to differentiate from malignant disease on radiologic studies. Ultrasound demonstrates renal enlargement with multiple anechoic or hypoechoic masses replacing the normal corticomedullary differentiation and a contracted pelvis. Peripelvic fibrosis may obscure acoustic shadowing from a central staghorn calculus. On computed tomographic scans, a staghorn calculus may be seen in a contracted renal pelvis of an enlarged kidney, with characteristic low-attenuation, peripherally enhancing rounded masses. Extrarenal extension of the inflammatory process is frequently seen.

Extraadrenal retroperitoneal paraganglioma: clinical, pathologic, and CT findings.

Paragangliomas of the retroperitoneum arise from specialized neural crest cells distributed along the aorta in association with the sympathetic chain. In order to ascertain characteristic CT features of extraadrenal retroperitoneal paragangliomas to differentiate them from other retroperitoneal tumors, 31 discrete tumors and two cases of paragangliomatosis in 28 patients were reviewed retrospectively, and the CT features were correlated with clinical and pathologic findings. There were 16 men and 12 women. Average age was 37 years (range, 11-70 years). Twenty-four patients (86%) had hypertension. Of these, catecholamine levels were elevated in all 18 patients who had biochemical studies. Four patients (14%) had malignant paragangliomas. The discrete tumors were classified by location as suprarenal (26%), renal hilar (32%), or infrarenal (42%). Suprarenal paragangliomas could not be distinguished from the ipsilateral adrenal gland on CT. The average size of functional tumors was smaller (7.0 cm) than that of nonfunctional tumors (12.0 cm), but the sizes of the two groups overlapped. Smaller tumors were more likely to be homogeneous and have well-defined margins than were larger tumors. Our findings indicate that extraadrenal retroperitoneal paragangliomas are functionally active more often than previously reported and that they are readily detected by CT as soft-tissue masses closely associated with the entire length of the abdominal aorta. However, no CT feature was found that was unique for paraganglioma.

From the archives of the AFIP. Malignant germ cell tumors of the ovary: radiologic-pathologic correlation.

Malignant germ cell tumors are the most common malignant ovarian neoplasms in girls and young women. The most well known of these neoplasms are dysgerminoma, immature teratoma, endodermal sinus tumor, and a mixture of two or more of these elements. All malignant germ cell tumors, especially immature teratoma, can be associated with mature (benign) teratoma. These tumors are generally large and have a complex but predominantly solid appearance on cross-sectional images. Elevated serum alpha-fetoprotein and human chorionic gonadotropin levels can help establish the diagnosis. Cystic areas of calcifications suggestive of mature teratoma do not exclude a co-existing malignant neoplasm.

From the Archives of the AFIP. Microcystic adenoma of the pancreas.

Microcystic adenoma is a benign pancreatic neoplasm typically seen in elderly women. Presenting symptoms and signs such as pain, weight loss, jaundice, and a palpable mass are usually observed, but the lesion may be incidental and does not necessarily require excision. The tumor is generally large and well demarcated. It contains innumerable small cysts, giving it a honeycombed appearance. On computed tomographic scans, the hypervascular tumor has attenuation values close to those of water before contrast material is administered, but it usually enhances afterward. On sonograms, it is often predominantly echogenic, although some larger cysts may be seen. A calcified central scar may be seen with either modality.

MR and CT evaluation of intracranial sarcoidosis.

Fourteen patients with CNS manifestations of neurosarcoidosis were evaluated by MR imaging and CT. Evaluations were done on a 0.5-T superconductive magnet with T1- and T2-weighted sequences. CT with contrast was obtained in all patients. The granulomatous lesions were classified by location into basilar, convexity, intrahemispheric, and periventricular white-matter involvement. Hydrocephalus with or without an associated lesion was also noted. MR determined the presence of disease in all patients (100%), but was less accurate than CT in depicting disease in two patients (14%). CT determined the presence of disease in 12 patients (85%) and was less accurate than MR in delineating hypothalamic involvement in two patients and periventricular white-matter disease in three patients. There was great variability in the appearance of intracranial sarcoidosis on MR. Three patients had lesions that were isointense or hypointense (relative to cerebral cortex) on both T1- and T2-weighted images while nine patients had lesions that were hyperintense on T2-weighted images. Convexity involvement and hydrocephalus were well documented by both CT and MR. These results indicate that both MR and CT are helpful in fully evaluating a patient with suspected intracranial sarcoidosis.