Skeletal muscle metastases: a three-part study of a not-so-rare entity.

OBJECTIVE: Our purposes were to explore the epidemiology of metastases to skeletal muscle and their detection on fused positron emission tomography and computed tomography. MATERIALS AND METHODS: We evaluated the epidemiology of skeletal muscle metastases in the literature and among cases from our hospital and studied the prevalence and appearance of skeletal muscle metastases among 433 patients undergoing fused positron emission tomography and computed tomography for non-small-cell lung cancer. RESULTS: We found 264 cases of skeletal muscle metastases in 151 articles. Mean age was 57.8 years with 67% men. At our hospital we studied 70 cases. Mean patient age was 55.7 years with 63% men. The most common source was lung cancer, and the most common site of involvement was the muscles of the trunk. Among our lung cancer patients undergoing fused positron emission tomography and computed tomography, we found 7 (1.6%) with skeletal muscle metastases. In only one of these seven patients was the metastasis first discovered by another imaging modality. In one patient discovery of the metastasis at fused positron emission tomography and computed tomography changed management. CONCLUSION: Skeletal muscle metastases are not rare. They may be more apparent at fused positron emission tomography and computed tomography than at other staging examinations, particularly contrast-enhanced CT scanning. Radiologists need to be alert to their presence when interpreting staging examinations in cancer patients.

Significance of upper urinary tract urothelial thickening and filling defect seen on MDCT urography in patients with a history of urothelial neoplasms.

OBJECTIVE: The purpose of this article is to assess the ability of CT urography to depict urothelial tumors in the upper renal collecting systems, compared with ureteroscopy and pathologic analysis, and to describe the relative implication of the radiologic signs of urothelial thickening and endoluminal filling defects. MATERIALS AND METHODS: We conducted a retrospective study to evaluate 326 consecutive CT urography examinations (using the split-bolus technique) performed at our institution between February 2006 and May 2009 in 188 patients (145 men and 43 women; median age, 65.5 years; range, 32.4-90.2 years) undergoing surveillance because of a history of urothelial tumor. Initial CT urography reports from multiple board-certified body imaging radiologists were reviewed for upper tract lesions and were classified by radiologic sign (filling defect or urothelial wall thickening) and lesion location (pelvicalyceal or ureteral) by one of the authors. The reference standard for comparison was pathologic analysis or visualization of tumor on ureteroscopy. Sensitivity and positive predictive values (PPVs) were calculated for upper tract tumors. RESULTS: Thirty-eight lesions were reported on initial CT urography examinations, 24 of which were subsequently confirmed to be tumors (PPV, 63.2%). Urothelial thickening was reported in 14 lesions, nine of which were tumors (PPV, 64%). Endoluminal filling defects were seen in 24 lesions, 15 of which were tumors (PPV, 62.5%). When stratified by location, urothelial thickening was more predictive of tumor in the pelvicalyceal system (PPV, 87.5% [7/8]) than in the ureter (PPV, 33.3% [2/6]). In contrast, filling defects were more predictive in the ureter (PPV, 87.5% [7/8]) than in the pelvicalyceal system (PPV, 50% [8/16]). CT urography failed to depict four tumors. CONCLUSION: Our data confirm that CT urography has utility in the surveillance of upper tract tumors. Urothelial thickening is an important radiologic sign of tumor, especially in the pelvicalyceal system.

Imaging and staging of transitional cell carcinoma: part 1, lower urinary tract.

OBJECTIVE: Transitional cell carcinoma (TCC) of the bladder is one of the most common malignancies affecting the genitourinary tract and is characterized by multifocality and a high incidence of recurrence. Radiologists play an important role in the staging and surveillance of this malignancy. In this article, we discuss the epidemiology, pathologic characteristics, and patterns of tumor spread of bladder carcinomas. We illustrate and focus on the role of imaging in the diagnosis, staging, and surveillance of TCC. CONCLUSION: The hallmark of TCC is multiplicity and recurrence. Cystoscopy is the method of choice for evaluation of the primary tumor in patients with bladder carcinoma. Imaging acts as an adjunct to accurately stage disease in these patients. Nearly 2-4% of patients with bladder cancer develop upper tract TCC. Hence, surveillance of the upper tract, in which imaging plays a central role, is an important component in the management of TCC. As in every other cancer, we face some limitations in nodal staging of TCC, particularly when the nodes are not enlarged. Development and validation of newer scanning techniques and MR contrast agents may help address some of these limitations in the future.

Imaging and staging of transitional cell carcinoma: part 2, upper urinary tract.

OBJECTIVE: Transitional cell carcinoma (TCC) of the upper urinary tract is a common malignancy affecting the genitourinary tract. It is commonly multifocal with a high incidence of recurrence requiring rigorous urothelial surveillance. In this article, we discuss the epidemiology, pathologic characteristics, and patterns of tumor spread. We illustrate and discuss the role of imaging in the diagnosis, staging, and surveillance of TCC of the renal pelvis and the ureter. CONCLUSION: The hallmark of TCC is multiplicity and recurrence. Nearly 2-4% of patients with bladder cancer develop upper tract TCC, but 40% of patients with upper tract TCC develop bladder cancer. Diagnosis of upper tract TCC is heavily dependent on imaging. Understanding the appearances of upper tract TCC on the different imaging techniques used is important in the accurate interpretation of imaging studies. Newer techniques such as CT urography are now increasingly used instead of conventional excretory urography in the surveillance of the upper tract in patients with bladder cancer.

Papillary renal cell carcinoma: radiologic-pathologic correlation and spectrum of disease.

Papillary renal cell carcinoma (pRCC) is the second most common type of renal cell carcinoma (RCC). pRCC has unique imaging and clinical features that may allow differentiation from clear cell RCC (cRCC). There have been significant advances in our knowledge of the natural history and treatment of pRCC, with data suggesting that it may be best to manage pRCC differently from the other subtypes of RCC. At contrast material-enhanced computed tomography, pRCC enhances less than does cRCC in all phases of contrast-enhanced imaging. The difference in the degree of enhancement between pRCC and cRCC is due to differences in their intratumoral vascularity. In general, if a heterogeneous mass enhances to a degree similar to that manifested by the renal cortex, it is likely to be a cRCC. A mass that enhances to a lesser degree is likely to be a non-clear cell RCC. It is common for metastatic lesions from pRCC to show enhancement characteristics similar to those of the primary tumor and be hypovascular.

Renal cell carcinoma: diagnosis, staging, and surveillance.

OBJECTIVE: This educational review focuses on the staging and radiologic evaluation of renal cell carcinoma. It includes discussion of the epidemiology, pathology, and therapeutic options of renal cell carcinoma and the implications for radiologic follow-up. CONCLUSION: The incidence of renal cell carcinoma has been increasing. Imaging plays a central role in its detection, staging, and treatment evaluation and follow-up.

Imaging of urethral disease: a pictorial review.

Retrograde urethrography and voiding cystourethrography are the modalities of choice for imaging the urethra. Cross-sectional imaging modalities, including ultrasonography, magnetic resonance (MR) imaging, and computed tomography, are useful for evaluating periurethral structures. Retrograde urethrography is the primary imaging modality for evaluating traumatic injuries and inflammatory and stricture diseases of the male urethra. Sonourethrography plays an important role in the assessment of the thickness and length of bulbar urethral stricture. Although voiding cystourethrography is frequently used to evaluate urethral diverticula in women, MR imaging is highly sensitive in the demonstration of these entities. MR imaging is also accurate in the local staging of urethral tumors.

Urogenital trauma: imaging upper GU trauma.

OBJECTIVES: This article will define the current controversies and concepts in the classification, clinical presentation, imaging approaches and management of upper urinary tract trauma. MATERIALS AND METHODS, RESULTS: This review will include the experience of the authors in the field of renal trauma over a 32-year period. Current thinking accepts the view that significant renal trauma is generally present when there is gross hematuria, signs of shock, or other clinical signs of severe injury. In most patients, suspected renal injury will be evaluated as a part of the overall assessment of the patient for suspected intraperitoneal injury. The authors will stress some exceptions to the rule. CONCLUSIONS: Most trauma experts now advocate conservative management, unless the patient is unstable or a renal vascular thrombosis or avulsion is suspected. Similarly, penetrating trauma to the kidney in and of itself no longer requires mandatory surgery. In the United States, computed tomography (CT), especially spiral CT, is considered the best diagnostic study, if available. Intravenous pyelography (IVP) is adequate if this is the only imaging modality available and if no concomitant injuries to the abdominal structure are suspected. Ultrasound, although strongly advocated in some countries, can lead to some significant false negatives. The diagnosis and management of unusual problems such as the traumatic AV fistula, the patient with an absent kidney or injury to the congenitally abnormal kidney, the serendipitous renal tumor in a patient with trauma, or serious bleeding after an apparent minor injury (i.e., spontaneous hemorrhage) are also reviewed in this article.