Magnetic resonance imaging for assessment of vena caval tumor thrombi: a comparative study with venacavography and computerized tomography scanning

Imaging of Solid Renal Masses

The increase in serendipitous detection of solid renal masses on imaging has not resulted in a reduction in mortality from renal cell carcinoma. Consequently, efforts for improved lesion characterization have been pursued and incorporated into management algorithms for distinguishing clinically significant tumors from those with favorable histology or benign conditions. Although diagnostic imaging strategies have evolved for optimized lesion detection, distinction between benign tumors and both indolent and aggressive malignant neoplasms remain an important diagnostic challenge. Recent advances in cross-sectional imaging have expanded the role of these tests in the noninvasive characterization of solid renal tumors.

Intraoperative detection of inferior vena caval tumor thrombus extending from metastatic lymph node of renal cell carcinoma using ultrasonography

A 67-year-old man consulted our department with gross hematuria. Computed tomography (CT) revealed a huge renal tumor with a paracaval metastatic lymph node (mLN). Right total nephrectomy was planned for the renal tumor diagnosed as renal cell carcinoma preoperatively. Just before the resection of the renal vein and artery, intraoperative ultrasonography revealed an inferior vena caval tumor thrombus (IVCTT) extending from the mLN. Ultrasonography clearly and dynamically demonstrated a rhythmic flapping movement of the IVCTT with blood flow in the inferior vena cava. Following right radical nephrectomy, IVCTT resection with the vessel wall was performed to reduce the risk of pulmonary tumor thrombus. Histopathological diagnosis of the renal tumor was clear cell renal cell carcinoma, and the resected IVCTT was confirmed histopathologically as tumor involvement from the mLN of the renal cell carcinoma. Intraoperative ultrasonography can detect IVCTT extending from the mLN, whereas CT cannot.

Staging, surveillance, and evaluation of response to therapy in renal cell carcinoma: role of MDCT

Renal cell carcinoma is the most common malignant renal tumor in the adults. Significant advances have been made in the management of localized and advanced renal cell carcinoma. Surgery is the standard of care and accurate pre-operative staging based on imaging is critical in guiding appropriate patient management. Besides staging, imaging plays a key role in the post-operative surveillance and evaluation of response to systemic therapies. Both CT and MR are useful in the staging and follow up of renal cell carcinoma, but CT is more commonly used due to its lower costs and wider availability. In this article, we discuss and illustrate the role of multi-detector CT in pre-operative staging, post-operative surveillance, and evaluation of response to systemic therapy in renal cell carcinoma.

Adrenocortical carcinoma initially presenting with hypokalemia and hypertension mimicking hyperaldosteronism: a case report

Background

Adrenocortical carcinoma is a rare malignancy and rare cause of Cushing’s syndrome.

Case presentation

A 65-year-old seemingly well male patient was referred to our clinic under the suspicion of hyperaldosteronism due to hypertension combined with hypokalemia. However, his serum aldosterone and plasma renin activity were within normal limits. Instead, Cushing’s syndrome was diagnosed by elevated urine free cortisol and a non-suppressible dexamethasone test. Abdominal computed tomography showed a 7.8 × 4.8 cm mass lesion at the right adrenal gland with liver invasion. Etomidate infusion was performed to reduce his cortisol level before the patient received a right adrenalectomy and liver wedge resection. The pathology report showed adrenocortical carcinoma with liver and lymph node metastasis. According to the European Network for the Study of Adrenal Tumors (ENSAT) staging system, the tumor was classified as T4N1M1, stage IV. Recurrent hypercortisolism was found shortly after surgery. The patient died of Fournier’s gangrene with septic shock on the 59^th day after diagnosis.

Conclusions

We report a case of rapidly progressive stage IV adrenocortical carcinoma with initial presentations of hypokaelmia and hypertension, mimicking hyperaldosteronism.

Renal cell carcinoma : clinical features and management

In 1999 it was estimated that renal cell carcinoma (RCC) would account for 29,990 new cancer cases diagnosed in the United States (61% in men and 39% in women), and lead to 11,600 deaths. RCC accounts for 2-3% of all malignancies in adults and causes 2.3% of all cancer deaths in the United States annually (1). Approx 4% of all RCC cases are bilateral at some point in the life of the patient. Data from over 10,000 cases of renal cancer entered in the Connecticut Tumor Registry suggests an increase in the incidence of renal cancer from 1935-1989; in women the incidence increased from 0.7 to 4.2 in 100,000, and in men from 1.6 to 9.6 in 100,000 (2). Factors implicated in the development of RCC include cigarette smoking, exposure to petroleum products, obesity, diuretic use, cadmium exposure, and ionizing radiation (3-9).

Role of intraoperative US in the decision for radical or partial nephrectomy

PURPOSE

To investigate the effect of intraoperative ultrasonographic (US) findings on the decision for the type of nephrectomy to be performed in patients who had renal tumors that were preoperatively evaluated by using magnetic resonance (MR) imaging, with pathologic results as the reference standard.

MATERIALS AND METHODS

The institutional review board approved the study protocol, and informed consent was obtained. Between June 2008 and September 2009, 44 patients (25 men, 19 women; mean age, 56.6 years; range, 28-76 years) with 46 renal tumors were prospectively assessed by using intraoperative US examinations to demonstrate tumor relationship with the nontumoral intact parenchyma. Findings at preoperative MR examinations were retrospectively evaluated by two radiologists to determine the type of surgery that would be recommended. The reference standard was results of pathologist's review of gross specimens and postoperative reports. The observers assigned their decisions as follows: score group 1, radical nephrectomy should be (should have been) performed; score group 2, partial nephrectomy can be (could have been) attempted; and score group 3, partial nephrectomy should be (should have been) performed.

RESULTS

Radical nephrectomy was performed in 36 lesions. In all cases, the intraoperative US observer and the pathologist were concordant in the decision that radical nephrectomy versus partial nephrectomy could or should have been performed. MR observers 1 and 2 overcalled the need for radical nephrectomy in seven and four cases, respectively. Compared with pathologic results, the overall correlation of intraoperative US was 0.991, and the correlation for MR observer 1 was 0.786 and that for MR observer 2 was 0.731.

CONCLUSION

Intraoperative US can be suggested as a valuable examination method in patients with tumors at a central location with suspicious renal sinus extension demonstrated by using MR imaging. The close cooperation of urologist and radiologist in renal tumor work-up could reduce performance of unnecessary radical nephrectomy.

Management of endocrine manifestations and the use of mitotane as a chemotherapeutic agent for adrenocortical carcinoma

Adrenal cortical carcinoma (ACC) is a rare malignancy in which patients have poor overall 5-year survival. Patients with ACC can present with symptoms of hormone excess, including Cushing's syndrome, virilization, feminization, or--less frequently--hypertension with hypokalemia. In many patients with ACC, advanced disease at presentation precludes surgery or is followed by local relapse or distant metastatic disease that cannot be managed surgically. In these instances, chemotherapy is often tried, but its limited efficacy all too often leaves the problem of persistent hormonal excess. Physicians who treat patients with ACC and severe hypercortisolism should recognize that uncontrolled hormone production is a malignant disease, which has severe consequences that require aggressive management. Because chemotherapy benefits only a small percentage of patients, steroidogenesis inhibitors, including mitotane, ketoconazole, metyrapone, and etomidate, should be used singly or in combination even as chemotherapy is administered. Diligent management with frequent adjustments is required, especially in patients with chemotherapy-refractory tumors that continue to grow. In the absence of randomized, controlled trials, adjuvant use of mitotane remains controversial, although the authors of a recent case-control study argue for its use. Despite difficulty administering effective doses, most clinicians agree that mitotane should be used if the tumor cannot be removed surgically or should be used as adjuvant therapy if there is a high likelihood of recurrence. The option of long-term monotherapy is restricted to patients who tolerate mitotane and either experience a clinical response or are at high risk for recurrence. Recommendations are provided to help manage patients with this difficult disease and to improve the quality of their lives.

The accuracy of multidetector computerized tomography for evaluating tumor thrombus in patients with renal cell carcinoma

PURPOSE

New advances in computerized tomography, including multidetector computerized tomography with 3-dimensional reformatting has recently called into question the absolute need for magnetic resonance imaging for evaluating renal cell carcinoma with suspected venous involvement. We assessed the accuracy of multidetector computerized tomography for predicting tumor thrombus and the level of venous involvement in patients with renal cell carcinoma.

MATERIALS AND METHODS

We retrospectively reviewed clinical and pathological features in 41 patients with renal cell carcinoma who underwent staging multidetector computerized tomography before surgery. Multidetector computerized tomography findings regarding the presence and level of tumor thrombus were compared to findings at surgery and at final pathological evaluation. All multidetector computerized tomography studies were read by a single radiologist (EKF) before surgery.

RESULTS

When excluding patients with segmental venous involvement only, the concordance rate between multidetector computerized tomography and pathological findings was 84%. Multidetector computerized tomography accurately predicted the level of tumor thrombus in 26 of 27 patients (96%). Four cases of negative multidetector computerized tomography findings were up staged to renal vein involvement based on pathological findings. All 4 patients had early distal thrombi that did not change operative management.

CONCLUSIONS

Multidetector computerized tomography with 3-dimensional mapping is an effective imaging modality for accurately characterizing the level of venous thrombus in patients with renal cell carcinoma. This modality effectively identified patients with clinically significant venous thrombus. Patients with renal cell carcinoma in whom multidetector computerized tomography fails to detect tumor thrombus are unlikely to have a tumor thrombus found at surgery that would change the surgical approach.

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.

Surgery insight: management of renal cell carcinoma with associated inferior vena cava thrombus

Renal cell carcinoma with inferior vena cava thrombus can be a diagnostic and therapeutic challenge; however, the surgical resection of these tumors can be facilitated by appropriate preoperative imaging and planning. First and foremost, we believe that this procedure should be considered an operation on the inferior vena cava rather than on the kidney. The level and extent of the tumor thrombus dictates the surgical approach used. Although the patient should be given an appropriate explanation of the procedure and its risks, the surgeon needs to be adequately prepared and have intraoperative versatility in order to maintain the safety of this operation. In this Review, we describe our approach to surgical resection in patients who have renal cell carcinoma with inferior vena cava thrombus, and outcomes for the management of patients with this disorder.

Evaluation of tumor thrombi in the inferior vena cava with intraoperative ultrasound

To report and discuss four cases of renal cell carcinoma (RCC) in which preoperative investigations yielded contradictory results regarding the cranial extension of propagation of the tumor thrombus into the vena cava. An intraoperative ultrasound scan (IOU) was performed in all cases to identify the exact level of the tumor thrombus. We have performed an IOU of the vena cava in four patients with RCC propagation into the inferior vena cava. Preoperative investigations were performed in all patients and consisted of abdominal Ultrasound scan (USS), contrast enhanced CT scan and gadolinium enhanced MRI scan. Intraoperative ultrasound has identified correctly the cranial extension and the absence of tumor thrombus infiltration in all patients. The thrombus reached the suprahepatic vena cava in two cases and was confined to the infrahepatic vena cava in the remainder. Preoperative imaging investigation had failed to determine the correct cranial extension of the tumor thrombus in two patients.IOU is a very useful tool to accurately assess the precise extent of tumor thrombus and eventually the presence of vein wall infiltration. These data are of paramount importance to plan the optimal surgical approach. According to our experience this type of investigation identifies the cranial extent of a tumor thrombus inside the vena cava better than standard imaging techniques.

Novel Techniques for Tumor Thrombectomy for Renal Cell Carcinoma With Intraatrial Tumor Thrombus

BACKGROUND

Radical nephrectomy with tumor thrombectomy in patients with renal cell carcinoma and level I to III thrombus extension is directly associated with an improved prognosis. However, radical surgery in patients with level IV thrombus extension is associated with high perioperative mortality, even if long-term survival is possible. In this report, we describe an alternative technique of vena caval and intraatrial tumor thrombectomy to decrease perioperative mortality and morbidity.

METHODS

A cohort of 6 patients aged 46, 50, 53, 56, 54, and 52 years underwent radical nephrectomy with tumor thrombectomy from the vena cava and right atrium under mild hypothermic cardiopulmonary bypass and intermittent cross-clamping of the supraceliac abdominal aorta. Intraatrial tumor thrombectomy was performed on a beating, perfused heart in 4 patients and a hypothermic, cardioplegia-perfused heart in 2 patients.

RESULTS

There were no early or late deaths. The aortic cross-clamp time was 12 and 15 minutes for patients 5 and 6, respectively. The cumulative hepatic and renal ischemic time was 16 minutes (range, 14 to 22 minutes) at 32 degrees C. The mean cardiopulmonary bypass time was 53.3 +/- 8.9 minutes (range, 40 to 65 minutes). At a mean follow-up of 43 +/- 24.6 months (range, 10 to 70 months), all patients are active and remain disease-free.

CONCLUSIONS

We conclude that radical nephrectomy and tumor thrombectomy in patients with level IV thrombi can be safely performed with cardiopulmonary bypass, mild hypothermia. and intermittent supraceliac abdominal aortic occlusion, avoiding potential hematologic, hepatic, renal, neurologic, and septic complications associated with circulatory arrest.

Resection of recurrent inferior vena cava tumor after radical nephrectomy for renal cell carcinoma

Management of recurrent tumor in the inferior vena cava (IVC) after radical nephrectomy is surgically challenging. We report 3 cases of recurrent renal cell carcinoma within the IVC managed by three different surgical techniques. One patient was treated with tumor thrombus removal and primary cavotomy closure. The second patient was treated with IVC ligation and removal without vascular reconstruction. A third patient was treated with IVC wall excision and placement of a bovine pericardium graft. Although technically difficult, repeat resection of IVC tumor recurrence after nephrectomy for renal cell carcinoma is an acceptable method of treatment.

Renal cell carcinoma associated with tumor thrombus in the inferior vena cava: surgical strategies

The purpose of this study was to evaluate strategies used for surgical management of renal cell carcinoma with a tumoral thrombus extension in the inferior vena cava (IVC). From January 2000 to December 2001, urological and vascular surgeons jointly undertook surgical treatment on 10 patients with renal cell carcinoma and tumor thrombus in the IVC. There were five women and five men, with a mean age of 60.2 years. The limit of thrombus extension, classified according to the Neves and Zincke system, was level I (renal) in one patient, level II (infrahepatic) in one, level III (retrohepatic) in three, and level IV (atrial) in five. Exposure was achieved by chevron bilateral subcostal laparotomy associated with sternotomy in three patients, bilateral subcostal laparotomy in six, and median sternolaparotomy in one. Radical nephrectomy associated with caval thrombectomy was performed in all patients. Cardiopulmonary bypass was used in four of the five level IV patients. The fifth patient was contraindicated for cardiopulmonary bypass. Transesophageal echography (TEE)-guided endoluminal occlusion of the unobstructed infradiaphragmatic IVC was performed in patients with level III thrombus. Clamping of the IVC was performed in patients with levels I and II thrombus. All procedures were assisted by continuous TEE surveillance. No intraoperative gas or tumor emboli were detected by TEE. The mean number of red blood cell units transfused during the course of hospitalization was 9.7 (range 2-22, median 9). One patient died of multiple organ failure on the day 28 after the procedure. The mean duration of hospitalization was 16 days. The mean duration of follow-up was 9.7 months. During follow-up, two of the remaining nine patients died due to tumor recurrence. Tumor recurrence was also detected in one of the seven surviving patients. Surgery for renal cell carcinoma with tumor thrombus in the IVC must be carried out in a specialized facility with the assistance of TEE surveillance and, in some cases, cardiopulmonary bypass. Operative treatment improves the prognosis of renal cell carcinoma with tumor thrombus in the IVC. In patients with level III thrombus, TEE-guided endoluminal occlusion of the unobstructed infradiaphragmatic IVC simplifies surgical management by obviating the need for exposure of the retrohepatic and supradiaphragmatic IVC.

Multidetector computed tomography vs magnetic resonance imaging for defining the upper limit of tumour thrombus in renal cell carcinoma: a study and review

OBJECTIVE

To compare the findings of multidetector computed tomography (CT) with surgical pathology and magnetic resonance imaging (MRI), to determine the accuracy of delineating the superior extent of inferior vena cava (IVC) thrombotic involvement in renal cell cancer (RCC).

PATIENTS AND METHODS

A prospective database was examined of 11 patients (median age 65 years, range 45-77) being assessed for suspected IVC extension of RCC tumour thrombus with both multidetector CT and MRI. All had pathology confirming RCC, and eight of those undergoing surgery had pathological confirmation of tumour thrombus extent. All images were analysed originally, then re-analysed by two independent radiologists, an experienced urologist and a urological trainee unaware of the original reports and other imaging results, with a final determination on tumour thrombus level by consensus.

RESULTS

The multidetector CT results were completely accurate when compared with surgical specimens and were in agreement with MRI on all but one occasion, where MRI determined the renal vein to be clear when it was involved on CT and at surgery, giving MRI an accuracy of seven of eight samples.

CONCLUSIONS

Whilst there were few patients and further studies are needed, multidetector CT was comparable with MRI in determining tumour thrombus level. More importantly, in the eight patients with surgical pathological confirmation, multidetector CT was accurate in all. Ultimately, it may replace MRI as the 'gold standard' for imaging to delineate the upper limit of tumour thrombosis in RCC.

Preoperative staging of renal cell carcinoma with inferior vena cava thrombus using multidetector CT and MRI: prospective study with histopathological correlation

OBJECTIVE

To evaluate the accuracy of multidetector computed tomography (CT) and magnetic resonance imaging (MRI) in staging and estimating renal carcinomas with caval thrombus.

METHODS

Initially, 23 patients with suspected caval thrombi were admitted into this prospective study. Triphasic CT imaging was performed using a multidetector CT with a reconstructed slice thickness of 2 mm. 3D CT reconstructions were used to improve surgical planning. MRI protocol included: a transversal T1-weighted GE sequence with and without Gd-DTPA, a transversal T2-weighted respiratory-gated TSE, and a coronal T1-weighted GE sequence with Gd-DTPA and fat saturation. In addition, a multiphase 3D angiography was performed after Gd-DTPA injection. Patients were divided into 3 groups: caval thrombus below the insertion of the hepatic veins, within the intrahepatic vena cava, and intra-atrial extension. The results the tumor thrombus extension and staging results of 2 independent readers were correlated with surgical and histopathological staging.

RESULTS

Of the 23 patients admitted, CT and MR scans of 14/13 patients respectively were correlated with histopathological workup. CT thrombus detection sensitivity and specificity for both readers was 0.93 and 0.8 respectively. MRI sensitivity and specificity for both readers was 1.0/0.85 and 0.75. Readers I and II evaluated the uppermost extension of the cranial tumor thrombus by both CT and MRI. CT and MR accuracy was 78% and 72%, 88% and 76% respectively.

CONCLUSION

In cases of a suspected tumor thrombus, MRI and multidetector CT imaging showed similar staging results. Consequently, these staging modalities can be used to assess the extension of the tumor thrombus.

Preoperative imaging in renal cell cancer

Renal cell cancer (RCC) represents the fifth most common cancer in men, with a rising incidence. Radical cancer surgery remains the only curative treatment in localized and advanced RCC. Therefore, preoperative imaging is most important for the planning of the surgical approach and strategy. The aim of any preoperative imaging in RCC is to differentiate benign from malignant lesions, to adequately assess tumor size, localization and organ confinement, to identify lymph node and/or visceral metastases, and to reliably predict the presence and extent of any thrombus of the vena cava. It is our aim to review the current status of preoperative imaging modalities in RCC. Computed tomography (CT) remains the most appropriate imaging modality to differentiate benign from malignant lesions. Although RCC can appear as iso-, hyper- or hypodense lesions on native CT scans, it usually demonstrates a significant contrast enhancement of about 115 HU and intratumoral areas of necrosis following the intravenous application of contrast medium. Benign masses such as renal oncocytoma are most often homogenous lesions exhibiting hypodensity compared to the normal renal parenchyma following the i.v. application of contrast dye. CT accurately predicts the tumor size with only a 0.5 cm difference as compared to the pathological size of the lesion. The identification of lymph node metastases still remains a problem since the limiting size is 4 mm and CT will result in a false negative rate of about 10%, especially in the presence of micrometastases; the false positive rate of 3-43% is mainly due to reactive hyperplasia. New technologies, such as the multidetector CT with thin collimation and multiplanar reformatting, might result in a diagnostic improvement. The involvement of the adrenal gland can be accurately predicted by CT scans or MRI, allowing an adrenal sparing approach in the case of unsuspicious findings. The detection of visceral metastases appears to be crucial since it has been shown that even patients with metastatic disease might benefit from radical nephrectomy followed by systemic immunotherapy in the case of a good performance status, and the presence of lymph node and pulmonary metastases only. Involvement of the renal vein and the vena cava with tumor thrombus formation will change the surgical strategy. Preoperatively, the presence and the cranial extent of the thrombus need to be known in order to plan the surgical approach. With regard to the extent of renal vein thrombi, a three phase helical CT scan is most appropriate; for vena caval thrombi only a MRI examination is able to accurately identify any infra- or suprahepatic as well as intracardial extension of the thrombus. The identification of multifocal lesions remains another unsolved problem in preoperative imaging techniques for RCC. Compared to the pathohistological analysis of nephrectomy specimens, neither ultrasonography, color duplex sonography nor regular CT scans are able to identify multifocal lesions with acceptable sensitivity and specificity. The evaluation of unenhanced CT scans together with the enhanced corticomedullary and the nephrogenic phase result in a 100% sensitivity and might represent a valuable option. Angiography has basically been abandoned from the armory of routine imaging techniques. It has, however, a current role in terms of the embolization of large tumors to reduce intraoperative blood loss, and in the palliative management of pain and bleeding due to RCC not amenable to surgery. Finally, we present a diagnostic algorithm for the most informative imaging techniques in the evaluation of RCC.

Preoperative imaging in renal cell cancer

Renal cell cancer (RCC) represents the fifth most common cancer in men, with a rising incidence. Radical cancer surgery remains the only curative treatment in localized and advanced RCC. Therefore, preoperative imaging is most important for the planning of the surgical approach and strategy. The aim of any preoperative imaging in RCC is to differentiate benign from malignant lesions, to adequately assess tumor size, localization and organ confinement, to identify lymph node and/or visceral metastases, and to reliably predict the presence and extent of any thrombus of the vena cava. It is our aim to review the current status of preoperative imaging modalities in RCC. Computed tomography (CT) remains the most appropriate imaging modality to differentiate benign from malignant lesions. Although RCC can appear as iso-, hyper- or hypodense lesions on native CT scans, it usually demonstrates a significant contrast enhancement of about 115 HU and intratumoral areas of necrosis following the intravenous application of contrast medium. Benign masses such as renal oncocytoma are most often homogenous lesions exhibiting hypodensity compared to the normal renal parenchyma following the i.v. application of contrast dye. CT accurately predicts the tumor size with only a 0.5 cm difference as compared to the pathological size of the lesion. The identification of lymph node metastases still remains a problem since the limiting size is 4 mm and CT will result in a false negative rate of about 10%, especially in the presence of micrometastases; the false positive rate of 3-43% is mainly due to reactive hyperplasia. New technologies, such as the multidetector CT with thin collimation and multiplanar reformatting, might result in a diagnostic improvement. The involvement of the adrenal gland can be accurately predicted by CT scans or MRI, allowing an adrenal sparing approach in the case of unsuspicious findings. The detection of visceral metastases appears to be crucial since it has been shown that even patients with metastatic disease might benefit from radical nephrectomy followed by systemic immunotherapy in the case of a good performance status, and the presence of lymph node and pulmonary metastases only. Involvement of the renal vein and the vena cava with tumor thrombus formation will change the surgical strategy. Preoperatively, the presence and the cranial extent of the thrombus need to be known in order to plan the surgical approach. With regard to the extent of renal vein thrombi, a three phase helical CT scan is most appropriate; for vena caval thrombi only a MRI examination is able to accurately identify any infra- or suprahepatic as well as intracardial extension of the thrombus. The identification of multifocal lesions remains another unsolved problem in preoperative imaging techniques for RCC. Compared to the pathohistological analysis of nephrectomy specimens, neither ultrasonography, color duplex sonography nor regular CT scans are able to identify multifocal lesions with acceptable sensitivity and specificity. The evaluation of unenhanced CT scans together with the enhanced corticomedullary and the nephrogenic phase result in a 100% sensitivity and might represent a valuable option. Angiography has basically been abandoned from the armory of routine imaging techniques. It has, however, a current role in terms of the embolization of large tumors to reduce intraoperative blood loss, and in the palliative management of pain and bleeding due to RCC not amenable to surgery. Finally, we present a diagnostic algorithm for the most informative imaging techniques in the evaluation of RCC.

Preoperative imaging in renal cell cancer

Renal cell cancer (RCC) represents the fifth most common cancer in men, with a rising incidence. Radical cancer surgery remains the only curative treatment in localized and advanced RCC. Therefore, preoperative imaging is most important for the planning of the surgical approach and strategy. The aim of any preoperative imaging in RCC is to differentiate benign from malignant lesions, to adequately assess tumor size, localization and organ confinement, to identify lymph node and/or visceral metastases, and to reliably predict the presence and extent of any thrombus of the vena cava. It is our aim to review the current status of preoperative imaging modalities in RCC. Computed tomography (CT) remains the most appropriate imaging modality to differentiate benign from malignant lesions. Although RCC can appear as iso-, hyper- or hypodense lesions on native CT scans, it usually demonstrates a significant contrast enhancement of about 115 HU and intratumoral areas of necrosis following the intravenous application of contrast medium. Benign masses such as renal oncocytoma are most often homogenous lesions exhibiting hypodensity compared to the normal renal parenchyma following the i.v. application of contrast dye. CT accurately predicts the tumor size with only a 0.5 cm difference as compared to the pathological size of the lesion. The identification of lymph node metastases still remains a problem since the limiting size is 4 mm and CT will result in a false negative rate of about 10%, especially in the presence of micrometastases; the false positive rate of 3-43% is mainly due to reactive hyperplasia. New technologies, such as the multidetector CT with thin collimation and multiplanar reformatting, might result in a diagnostic improvement. The involvement of the adrenal gland can be accurately predicted by CT scans or MRI, allowing an adrenal sparing approach in the case of unsuspicious findings. The detection of visceral metastases appears to be crucial since it has been shown that even patients with metastatic disease might benefit from radical nephrectomy followed by systemic immunotherapy in the case of a good performance status, and the presence of lymph node and pulmonary metastases only. Involvement of the renal vein and the vena cava with tumor thrombus formation will change the surgical strategy. Preoperatively, the presence and the cranial extent of the thrombus need to be known in order to plan the surgical approach. With regard to the extent of renal vein thrombi, a three phase helical CT scan is most appropriate; for vena caval thrombi only a MRI examination is able to accurately identify any infra- or suprahepatic as well as intracardial extension of the thrombus. The identification of multifocal lesions remains another unsolved problem in preoperative imaging techniques for RCC. Compared to the pathohistological analysis of nephrectomy specimens, neither ultrasonography, color duplex sonography nor regular CT scans are able to identify multifocal lesions with acceptable sensitivity and specificity. The evaluation of unenhanced CT scans together with the enhanced corticomedullary and the nephrogenic phase result in a 100% sensitivity and might represent a valuable option. Angiography has basically been abandoned from the armory of routine imaging techniques. It has, however, a current role in terms of the embolization of large tumors to reduce intraoperative blood loss, and in the palliative management of pain and bleeding due to RCC not amenable to surgery. Finally, we present a diagnostic algorithm for the most informative imaging techniques in the evaluation of RCC.

Management of adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare neoplasm with poor prognosis. Patients present with signs of steroid hormone excess (e.g. Cushing's syndrome, virilization) or an abdominal mass. Tumour size at presentation (mean diameter at diagnosis > 10 cm) is the most important indicator of malignancy. In addition, computed tomography (CT) typically demonstrates an inhomogeneous adrenal lesion with irregular margins and variable enhancement of solid components after intravenous contrast media. Magnetic resonance imaging (MRI) is equally effective as CT and is particularly helpful to visualize invasion into large vessels. Complete tumour removal (R0 resection) offers by far the best chance for long-term survival and therefore surgery is the treatment of choice in stage I-III ACC. Despite tumour resection for cure most patients will eventually develop local recurrence or distant metastases. Thus adjuvant treatment options need to be evaluated in high-risk patients (e.g. radiation therapy of the tumour bed and/or chemotherapy). In tumour recurrence re-operation should always be considered. In metastatic disease (stage IV ACC) not amenable to surgery mitotane (o,p'DDD) remains the first-line therapy. Drug monitoring is needed for effective treatment aiming at concentrations between 14 and 20 mg/l. Patients not responding to mitotane may benefit from cytotoxic chemotherapy (23% partial remissions, 4% complete remissions). Only large prospective multicentre trials comparing different treatment options will allow to make systematic progress in the management of ACC.

Applications of positron emission tomography imaging, intraoperative ultrasonography, magnetic resonance imaging, and angiography in the evaluation of renal masses

Most renal masses and cysts are adequately characterized by ultrasonography or computerized tomography. Occasionally, further diagnostic evaluation is needed. Magnetic resonance imaging has emerged as the premier study to evaluate suspected tumor thrombus and to plan the operative technique in challenging cases. Intraoperative ultrasonography is a valuable real-time imaging modality for delineating tumor extent and margins during nephron-sparing surgery and in evaluating the presence of synchronous multifocality. Additionally, localized central renal tumors can be treated with ultrasonography-guided radiofrequency ablation. Positron emission tomography has little use in the diagnostic evaluation of renal masses, but may be useful in staging equivocal cases and in evaluating suspected recurrence or metastases in patients after nephrectomy for renal cell carcinoma.

Intraoperative transesophageal sonographic monitoring of tumor thrombus in the inferior vena cava during radical nephrectomy and thrombectomy for renal cell carcinoma

We report the case of a 58-year-old woman with renal cell carcinoma in whom real-time transesophageal sonographic monitoring of the tumor thrombus in the inferior vena cava provided dynamic information, allowing us to determine the appropriate operative procedure to use. Observation of the thrombus throughout the operation showed that mobilization of the liver resulted in compression of the inferior vena cava against the spine, increasing the risk of migration of the tumor thrombus and reinforcing the need to maintain adequate positioning of the liver to prevent such compression. The surgery was completed successfully, and the patient's postoperative course was uneventful. We recommend the use of real-time transesophageal sonographic monitoring of the tumor thrombus during such surgical procedures.

Assessment of tumor invasion of the vena caval wall in renal cell carcinoma cases by magnetic resonance imaging

PURPOSE

We evaluated the role of magnetic resonance imaging (MRI) in patients with renal cancer and inferior vena caval involvement with reference to its ability to characterize the extent and nature of inferior vena caval tumor extension and wall invasion.

MATERIALS AND METHODS

The study included 12 consecutive patients with renal cancer and inferior vena caval involvement. All patients underwent imaging on a 1.5 Tesla MRI unit. Coronal, axial T1 and axial T2-weighted images were performed in all cases, while in 6 3-dimensional gadolinium enhanced magnetic resonance angiography and venography were also performed. Images were assessed for the extent and nature of tumor extension, that is tumor versus thrombus, and invasion of the inferior vena caval wall. Imaging results were compared with operative findings.

RESULTS

On MRI the extent and nature of the inferior vena caval tumor was correctly defined in all cases. The sensitivity, specificity and accuracy of inferior vena caval wall invasion were 100%, 89% and 92%, respectively.

CONCLUSIONS

In patients with renal cancer and inferior vena caval involvement MRI defines the tumor level in the inferior vena cava. It is also a sensitive technique for detecting vessel wall invasion and provides important preoperative information for surgical planning.

Diagnostic imaging in canine pheochromocytoma

The diagnosis of pheochromocytoma is challenging due to the variable presentations of patients affected with this neoplasm. This report describes four dogs with pheochromocytoma in which radiography, ultrasonography and computed tomography (CT) were key diagnostic tools. Computed tomography was the most useful imaging modality for assessment of size, shape and margination of the tumor. CT findings for the pheochromocytoma included a large, irregularly shaped mass in the dorsal midabdomen with multiple foci of low attenuation dispersed in hyperdense, highly vascular tissue. This neoplasm often invades the caudal vena cava and other surrounding organs therefore, although a pheochromocytoma may be identified in the absence of clinical signs, it should not be considered an incidental lesion. The unpredictable growth rate and potential for invasion of major vessels warrants serious consideration. Follow-up ultrasound and CT examinations are recommended for patients with adrenal masses that do not undergo surgical excision.

[Tumor thrombosis of the left renal vein and inferior vena cava secondary to renal cell carcinoma. Findings with ultrasonography, Echo-Doppler, and computerized tomography]

Renal cell carcinoma represents a 2.5-3% of all neoplastic processes, usually seen un patients older than 50 years. 60-75% are resectable at diagnosis, representing local or metastatic advanced disease the rest of them. This tumor tends to spread intravascularly, leading to tumoral thrombosis within the inferior caval vein (ICV) and renal vein 4-10% and 21-35% of cases, respectively. As the only effective treatment is surgical resection, preoperative determining of the thrombus extension is crucial. Thus, an accurate radiological study including ultrasound, doppler sonography, computed tomography and/or Magnetic Resonance, is key for these patients. We present a 49 year-old patient with renal cell carcinoma and associated tumoral thrombosis in inferior caval vein and left renal vein; we provide the most significant figures, explaining its most characteristic radiological findings.

MR imaging of renal masses interpreted on CT to be suspicious

OBJECTIVE

Prior studies have shown that renal MR contrast enhancement improves the efficacy of mass and proximal vascular evaluation. This study assessed the usefulness of different sequences for characterization of masses that appeared suspicious on CT and for prediction of their potential for malignancy.

SUBJECTS AND METHODS

In a prospective manner 32 patients (age range, 26-78 years: average age, 54 years), each with at least one suspicious mass on CT, were examined with MR imaging. The following sequences were performed: conventional spin-echo with and without fat saturation, fast spin-echo, and dynamic gadopentetate dimeglumine-enhanced infusion using a 1.5-T superconducting magnet. Results were analyzed and compared with pathologic results after resection.

RESULTS

A total of 65 renal masses of average size 2.6 cm (range, 1-10 cm) were detected with dynamic MR imaging. Seventeen of the 65 masses were malignant. Of the 17 malignant masses, three did not enhance on dynamic MR imaging (because of hemorrhage). Sixteen of the 17 malignant masses were heterogeneous on T2-weighted images. Three enhancing masses contained fat and all were angiomyolipomas. Thirty-five of the 65 masses (four with hemorrhage) did not show enhancement, all of which were homogeneous on T2-weighted images and were proven to be cysts. Five masses resulted from infections and had heterogeneous T2 appearance. The remaining masses were three hematomas with hemorrhage, one column of Bertin, and one aneurysm.

CONCLUSION

Renal masses that are interpreted as suspicious on CT may lack MR enhancement because of hemorrhage effects; heterogeneity of their T2 appearance is thus critical in differentiating malignancy from benign disease. Odds-ratio calculations give an adjusted estimate of a 3.36-fold increase (95% confidence interval, 1.8-6.27) in the likelihood of malignancy when masses are heterogeneous on T2-weighted images and a 29-fold increase (95% confidence interval, 3.67-241.8) for predicting malignancy when enhancement is present.

Inferior vena caval masses identified by echocardiography

The most common cause of an inferior vena caval mass is renal cell carcinoma that extends through the lumen, occurring in 47 of 62 patients (85%). Detection of an inferior vena caval mass affects the surgical approach requiring cardiopulmonary bypass for resection when the mass extends to the heart.

Resection of hypernephromas with vena caval or right atrial tumor extension using extracorporeal circulation and deep hypothermic circulatory arrest: a multidisciplinary approach

OBJECTIVE

Among retroperitoneal tumors, renal cell carcinoma most often invades the retrohepatic inferior vena cava or the right atrium. Even in these cases, radical nephrectomy may be performed with curative intention. The aim of this retrospective study was to elucidate the impact of cardiopulmonary bypass and hypothermic circulatory arrest on surgical complications, primary mortality, and long-term survival.

PATIENTS AND METHODS

From Jan. 1981 till Aug. 1996, 44 patients were operated upon for renal cell carcinoma with advanced vena caval extension. The patients were divided into two groups. In 19 cases (Cardiopulmonary Bypass Group), extracorporeal circulation and deep hypothermic circulatory arrest was used. The Conventional Technique Group comprised 25 patients who had radical nephrectomy, paraaortic lymphadenectomy and extirpation of the intracaval tumor thrombus applying common principles in vascular surgery. The median age was 59 years with a range from 42 to 78 years in the Cardiopulmonary Bypass Group, and 60 years, ranging from 22 to 72 years, in the Conventional Technique Group. In addition, both groups did not differ in gender, UICC TNMG staging classification, and perioperative risk factors. A review of the patient charts was done and surveys were sent to survivors or nearest of kin. Wilcoxon test and log-rank test were used as appropriate.

RESULTS

A lower intraoperative complication rate was found in patients who had surgery using cardiopulmonary bypass. This was especially true with embolization of the tumor thrombus into the pulmonary arteries: 0.0% in Cardiopulmonary Bypass Group and 16.0% in Conventional Technique Group (P < 0.05). Severe hemorrhage occurred in 10.5% (Cardiopulmonary Bypass Group) and 16.0% (Conventional Technique Group). This translated into a significantly lower perioperative mortality in the Cardiopulmonary Bypass Group when compared to the Conventional Technique Group (5.6 and 16.0%, respectively). In spite of these results, differences in long-term survival did not reach statistical significance. But, a trend to superior long-term survival was apparent. The mean survival was 1289 +/- 278 days in the Cardiopulmonary Bypass Group and 746 +/- 166 days in the Conventional Technique Group.

CONCLUSIONS

Due to acceptable long-term results, the resection of hypernephromas showing extensive vena caval invasion seems to be justified. The use of cardiopulmonary bypass and hypothermic circulatory arrest is able to decrease primary morbidity and mortality. However, the influence on long-term survival remains to be proven.

Preoperative transesophageal echocardiography for assessment of vena caval tumor thrombi: a comparative study with venacavography and magnetic resonance imaging

OBJECTIVES

Renal cell carcinoma extends into the inferior vena cava (IVC) in 4% to 10% of patients. The purpose of this study was to evaluate the diagnostic accuracy of preoperative transesophageal echocardiography (TEE) in determining the presence and level of IVC involvement in such cases.

METHODS

From June 1992 to December 1995, 13 patients with suspected IVC tumor thrombi were studied with preoperative TEE. These patients were also evaluated with either magnetic resonance imaging (MRI; n = 10), contrast venacavography (CVC; n = 8), or both of the latter (n = 5). All patients subsequently underwent surgical removal of the primary tumor and IVC thrombus. The presence and level of IVC thrombus at surgery was correlated with that predicted by the various preoperative imaging modalities.

RESULTS

Preoperative TEE accurately delineated the presence and extent of IVC tumor thrombus involvement in 11 of 13 patients (85%); the level of IVC involvement was overstaged in 1 patient and understaged in 1 patient. Accurate diagnostic information was provided by MRI in 9 of 10 patients (90%) and by CVC in 6 of 8 patients (75%).

CONCLUSIONS

In patients with IVC tumor thrombi, preoperative TEE can provide accurate information regarding the presence and extent of IVC involvement. However, TEE is an invasive and costly procedure with no diagnostic advantage over MRI in the preoperative evaluation of these patients.

Intracaval ultrasonography in the diagnosis of tumour involvement of the vena cava

A retrospective study of 34 consecutive patients with possible tumour involvement of the vena cava was performed to assess the usefulness of intracaval ultrasonography. Twenty-five of the 34 patients were operated and resection carried out in 23, including seven with combined resection of the vena cava. The sonographic criterion for vena cava invasion was obliteration of the echogenic ring of the vena cava wall or intracaval tumour mass. The sensitivity, specificity and overall accuracy of intracaval endovascular ultrasonography in the diagnosis of tumour involvement of the vena cava were 100, 96 and 97 per cent respectively. The respective values were 91, 61 and 71 per cent for computed tomography and 82, 67 and 72 per cent for cavography. Ultrasonography is a useful technique that can precisely evaluate the vena cava for possible tumour invasion, especially when the presence or extent of tumour involvement is not definitely established by conventional imaging techniques.

Vein invasion in renal cell carcinoma: impact on metastatic behavior and survival

PURPOSE

The development of a thrombus extending into the veins is well recognized in renal cell carcinoma. We investigated the hypothesis that vein invasion alone has no adverse impact on survival but is a highly negative factor in other tumors.

MATERIALS AND METHODS

In 200 consecutive patients invasion of the renal vein and vena cava was evaluated and compared with the clinical course.

RESULTS

A total of 26 patients had vena caval and 47 had renal vein invasion. Patients with venous invasion had a significantly shorter survival but no survival difference was demonstrated based on the level of involvement.

CONCLUSIONS

Our study indicates that vein invasion itself seems to be an important prognostic factor in renal cell carcinoma.

The utility of transesophageal echocardiography in the management of renal cell carcinoma with intracardiac extension

The accurate assessment of the distal extent of vena caval invasion of renal cell carcinoma into the hepatic veins, inferior vena cava, and right atrium is critical before surgical resection. We present two cases of renal carcinoma with vena caval extension in which preoperative transesophageal echocardiography accurately assessed tumor extent and guided surgical therapy. The role of transesophageal echocardiography in comparison to other diagnostic modalities is discussed.

Role of intravascular ultrasonography in detecting intravascular tumor thrombi: a preliminary report

BACKGROUND

We evaluated the role of intravascular ultrasonography in the diagnosis of intravascular tumor thrombi.

METHODS

During the past 2 years intracaval endovascular ultrasonography was performed in 26 selected patients to diagnose inferior vena cava invasion. Results of positive intracaval endovascular ultrasonogram were correlated with the pathologic findings of resected specimens and autopsy and with other imaging technologies such as computed tomography and angiography.

RESULTS

Six patients had positive studies of intracaval tumor thrombus. In all cases detailed horizontal images perpendicular to the inferior vena cava axis were studied. Five of the six patients underwent resection. Intravascular ultrasonography correctly predicted the extent of the tumor thrombus, the degree of tumor adherence to the vessel wall, and the intraluminal movement of the tumor thrombus. Floating thrombi were visualized as an intraluminal to-and-fro movement. Thrombus adhesion to the vessel wall appeared as an absence of space between the tumor and the wall, with no respiratory movement of the thrombus.

CONCLUSIONS

Intravascular ultrasonography was useful for the accurate diagnosis of intravascular tumor thrombi and aided in formulating the operative strategy.

Involvement of the inferior vena cava by renal tumour: surgical excision using hypothermic circulatory arrest

OBJECTIVE

To evaluate the immediate and long-term results of a radical surgical technique in the treatment of renal tumours with extensive involvement of the inferior vena cava (IVC).

PATIENTS AND METHODS

Seven patients with extensive involvement of renal tumours into the IVC were operated upon using a cardiopulmonary by-pass, hypothermia and cardiac arrest to facilitate surgery. Wide exposure of the IVC in a bloodless field permitted complete removal of all visible tumour in each case. Histological sections confirmed renal cell cancer in six patients and Wilms tumour in a 15-year-old girl.

RESULTS

All patients recovered well from their surgery with no major complications and spent one or two days in the Intensive Treatment Unit and an average of 13 days in hospital after the operation. Of the seven patients, four are alive and well with no obvious disease after an average follow-up time of 30 months (range 8-54). The other three patients have died from disseminated renal cancer.

CONCLUSION

This procedure provides good local control of the tumour and offers the only hope of cure in patients with this disease. In collaboration with the surgical cardiac team it can be safely carried out with acceptable morbidity and mortality.

Intraoperative ultrasound: determination of the presence and extent of vena caval tumor thrombus

OBJECTIVES

To report and discuss five cases of renal cell carcinoma (RCC) in which preoperative imaging studies were equivocal with regard to the presence and extent of vena caval tumor thrombus or in which dynamic intraoperative imaging of the vena cava was advantageous.

METHODS

We reviewed the cases of five patients who had conflicting preoperative imaging studies and reviewed the literature applying to this clinical situation.

RESULTS

Two patients whose preoperative magnetic resonance imaging studies suggested inferior vena caval tumor thrombus were shown, on intraoperative color Doppler ultrasound, not to have tumor thrombus but rather turbulent flow within the vena cava mimicking thrombus. In two patients intraoperative ultrasound (IOUS) was used to image the position of the tumor thrombus as it was manipulated to allow for safe vena caval clamp placement. In one patient we used real-time imaging to visualize thrombus extraction from the heart.

CONCLUSIONS

Intraoperative ultrasound real-time imaging is beneficial in two specific situations: in those cases in which the presence of renal vein or inferior vena cava involvement is equivocal based on preoperative imaging techniques and when there is a need to identify intraoperatively the limits of a known tumor thrombus to allow subsequent safe placement of a caval clamp.

Small hepatocellular carcinoma with intravascular tumor growth into the right atrium

A 66-year-old man with ascites and marked edema in the lower extremities was suspected of having secondary Budd-Chiari syndrome due to primary liver cancer, based on imaging diagnosis, i.e., ultrasonography, computed tomography, and inferior venacavogram. At autopsy, an encapsulated small liver cancer was found to have extended into the inferior vena cava and right atrium. There have been few reports of small hepatocellular carcinoma with intravascular tumor growth into the right atrium.

Intraoperative ultrasound in the evaluation of tumor involvement of the inferior vena cava

The successful excision of genitourinary malignancies extending to the inferior vena cava relies heavily on accurate preoperative imaging. For the majority of these patients magnetic resonance imaging, inferior venacavography, abdominal ultrasound or abdominal computerized tomography will reliably predict the extent of inferior vena caval involvement by tumor. However, occasionally the results of these studies will conflict or be called into question intraoperatively. We report on 8 patients considered to be at risk for inferior vena caval involvement by tumor and for whom intraoperative ultrasound was obtained to clarify the presence or extent of thrombus. Five patients had renal cell carcinoma and 3 had adrenal carcinoma. In all patients concern as to the extent or presence of tumor was based on either inconclusive preoperative studies or unexpected intraoperative findings. In each case intraoperative ultrasound clearly visualized the inferior vena cava and established the presence or extent of tumor invasion. In 4 patients venacavotomy was avoided as a consequence of these findings. Intraoperative ultrasound is a useful tool that can accurately assess the inferior vena cava for possible tumor invasion, especially when the presence or extent of tumor involvement is not definitively established preoperatively.