USE OF MAGNETIC RESONANCE IMAGING SCANNING IN ADRENOCORTICAL CARCINOMA WITH VENA CAVAL INVOLVEMENT
MARC H. SIEGELBAUM, M.D. JAMES E. MOULSDALE, M.D. JOSEPH B. MURPHY, M.D. GARTH R. MCDONALD, M.D.
From the Divisions of Urology and Cardiothoracic Surgery, Department of Surgery, Saint Joseph Hospital, Towson, Maryland
ABSTRACT-We report on 2 cases of an adrenocortical carcinoma with vena caval in- volvement. Preoperative evaluation included a magnetic resonance imaging (MRI) scan confirming the presence of vena caval involvement. Extremely precise detail of the vena caval tumor thrombus was very helpful in preparing for the surgical extirpation. MRI de- tail far outweighed what was seen on the computed tomography scan and venacavo- gram. The MRI scan correlated exactly with what was found surgically. Although MRI scanning has been used to evaluate renal tumors with vena caval extension, few cases have been reported with similar adrenal tumors.
Adrenocortical carcinomas are unusual lesions with their incidence approximately 1 per 1,500,000 cases.1,2 Although a well-established en- tity, not many cases of this tumor with vena caval involvement have been reported in the urologic lit- erature.
Traditional preoperative evaluation includes a computed tomography (CT) scan to assess for metastatic disease as well as to assess the status of vena caval involvement. Venacavography is an ad- junctive test that is traditionally used to evaluate vena caval involvement further.
Magnetic resonance imaging (MRI) scanning is a well-established test used in the evaluation of vena caval involvement in renal tumors, but few reports are available for its use in adrenocortical tumors with vena caval involvement.3,4
Precise evaluation of vena caval tumor throm- bus involvement is necessary in order to decide whether cardiothoracic bypass will be necessary.
We report on 2 patients with adrenocortical car- cinoma and vena caval involvement evaluated pre- operatively with MRI scanning. The utility of MRI scans in this setting is obvious.
CASE REPORT
CASE 1
A twenty-three-year-old white woman presented with a five-month history of progressive low back pain simulating possible renal colic. Her past med- ical history was significant for having been treated for a left renal stone with Double J stenting and ex- tracorporeal shock-wave lithotripsy, approximately one year previously.
Her review of systems was positive only for fre- quent headaches and some fatigue. Physical exam- ination was completely normal (including blood pressure) with the exception of a slightly palpable right upper quadrant mass.
An intravenous urogram suggested a right supra- renal mass (Fig. 1). A CT scan demonstrated the presence of an 18 cm calcified right adrenal tumor with vena caval involvement (arrow) (Fig. 2). A T1-weighted MRI scan confirmed the presence of vena caval tumor or thrombus, or both, well below the hepatic vasculature (Fig. 3A, B). All studies showed no evidence of lymphadenopathy or liver involvement and indicated that the mass was prob- ably separate from the upper pole of the right kid- ney. A venacavogram less precisely confirmed the presence of vena caval involvement (Fig. 4).
The serum cortisol, corticotropin, aldosterone, electrolytes, blood urea nitrogen (BUN), and
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creatinine were normal. Urine metanephrine, normetanephrine, vanillylmandelic acid (VMA), norepinephrine, and cortisol were normal. Urine 17-ketosteroids were 25.7 mg/24 hours (normal 6 to 15 mg/24 hours).
Cardiothoracic surgical consultation was ob- tained in the event cardiopulmonary bypass would be necessary for vena caval reconstruction.
Preoperative preparation with intravenous hy- drocortisone was instituted. The patient then un- derwent a right eighth interspace thoracoabdomi- nal radical adrenalectomy and lymphadenectomy with vena caval tumor thrombus excision. The tumor was found to be quite separate from the right kidney, which was spared. Proximal and dis- tal vena caval control was obtained with a fair dis- tance noted between the tumor and hepatic veins. A partial occlusion clamp could be applied to the vena cava and the adherent tumor thrombus was
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resected with a free margin. Reconstruction of the vena cava was then effected with a 5 by 2 cm saphenous vein patch that was fashioned in a spi- ral technique.5
Permanent section of the tumor revealed a poorly differentiated adrenal cortical carcinoma with focal vascular invasion below the capsule. The lymph nodes, perinephric fat, and vena caval re- section margin were all negative for tumor.
The patient had an uneventful postoperative course.
The Oncology Service did recommend mitotane therapy after a pulmonary recurrence developed.
The patient is alive and well now, sixty months postoperatively, without symptoms and without evidence of recurrence on CT and MRI scanning. In the interim, by the way, the patient gave birth to a healthy, full-term female child.
CASE 2
A seventy-two-year-old white woman presented with an asymptomatic abdominal mass on the left side. Her past medical history was only significant for hypertension, treated with Dyazide and atenolol, and an abdominal hysterectomy for be- nign disease. Her review of systems was otherwise negative. Physical examination was normal except for mild blood pressure elevation and a large ab- dominal mass.
This was investigated with CT scan documenting a large left adrenal mass with probable extension into the upper pole of the left kidney as well as in- volvement of the left renal vein and vena cava (Fig. 5). A T,-weighted MRI scan was done document- ing left renal vein replacement by tumor or throm- bus, or both, extending into the vena cava, below the hepatic vasculature (Fig. 6A,B). Again, all stud- ies showed no evidence of metastatic disease.
The serum cortisol, catecholamines, aldosterone, electrolytes, BUN, and creatinine were normal. The urinary metanephrine, normetanephrine, VMA, cortisol, and 17-ketosteroids were also normal.
Consultation with the cardiothoracic surgeon was obtained.
Following premedication with hydrocortisone, a subcostal left chevron incision and exploration was performed.
Because of body habitus, the size of the vena caval mass, and early instability (oxygen desatura- tion), thought to be secondary to tumor pul- monary emboli, the decision was made to use car- diopulmonary bypass. This was done through a contiguous median sternotomy incision.
After cardiopulmonary bypass was established, a nephroadrenalectomy with vena cava explo- ration and extraction of tumor thrombus was per- formed.
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Complete extraction of the vena caval tumor thrombus was accomplished, but the internal sur- face of the entire vena cava appeared slightly gran- ular. Because of the patient’s instability, no attempt at vena caval resection or reconstruction was made.
During the terminal portions of the operation, the patient became progressively hemodynamically unstable with poor oxygen saturation. This was complicated by the development of a coagulapathy. Despite vigorous resuscitative measures, cardiac arrest and death ensued. No postmortem examina- tion was obtained.
Permanent section of the tumor revealed a poorly differentiated adrenocortical carcinoma with renal vein invasion.
COMMENT
Vena caval involvement by adrenocortical carci- noma is rare. To the present, only about 10 cases have been reported in the urologic literature.6,7 Cahill and Sukov8 were the first to report on such a case and to manage it surgically.
Although the prognosis for such tumors is poor, ranging from 20 to 30 percent five-year survivals,9 surgery is still indicated. Surgery is the mainstay of treatment, since no effective adjuvant treatment is available. In adults, staging, age,9 and functional status10 of the tumor affect prognosis. Namely, younger patients with low-stage functioning tu- mors tend to fare better.
Once the diagnosis has been made, and the func- tional status of the tumor is determined with ap- propriate serum and urine studies, evaluation for metastatic disease and vascular involvement is es- sential.
With respect to vascular involvement, it is criti- cal to assess whether there is tumor thrombus pres- ent in the vena cava. If tumor thrombus is found, the exact extent, that is, infrahepatic, intrahepatic, suprahepatic, or supradiaphragmatic, must be identified. If the tumor thrombus is infrahepatic, then cardiothoracic bypass is usually unnecessary, and the tumor thrombus can be directly extracted from the vena cava after obtaining local control of the vena cava and performing a venacavotomy. If the tumor thrombus is at any of the other levels mentioned, then cardiothoracic bypass with circu- latory arrest and hypothermia is the preferred and safest method.11 This is done prior to venacavot- omy and vena caval exploration and extraction of the tumor thrombus.
CT scanning is the standard for evaluation of tumor size and involvement of other structures. Although CT scanning can certainly be used to
evaluate involvement of adrenal, renal, and vena caval vasculature, precise detail may be lacking, especially with reference to the vena cava. Ultra- sound can be helpful in evaluating vena caval in- volvement, but this, too, can be imprecise. It is certainly useful in evaluating the cardiac extent of tumor thrombus, however.
Venacavography is excellent in evaluating vena caval involvement, but this is an invasive proce- dure that may not give an anatomic perspective with reference to the surrounding vascular and solid organ structures.
As in renal tumors involving the vena cava, MRI scanning has become critical in the preoperative assessment. Since there have not been many re- ported cases of adrenocortical carcinomas with vena caval involvement, the efficacy of MRI scan- ning has not been evaluated. Presumably, however, since vascular involvement follows similar pat- terns, MRI should be equally as efficacious in adrenal pathologic conditions. 3,+
MRI scanning has several advantages over other imaging techniques. The ability to obtain images in the axial, sagittal, and coronal planes allows the surgeon to predict reliably the extent of vena caval tumor thrombus involvement with respect to the hepatic vasculature, thus being better able to plan properly a surgical approach.
Venacavography, with its limited images, cannot predict as accurately vena caval involvement as clearly as the multiplane images of the MRI scan- ning. Furthermore, since many of the adrenocorti- cal carcinomas are large and necrotic, any imaging method that can better evaluate surrounding solid organ structures is helpful. MRI scanning can also do this because of the ability to do sagittal and coronal images.12
We presented 2 cases of adrenocortical carci- noma with significant vena caval involvement. One case had comparison studies of the MRI scan and venacavography; the other had just the MRI scan. In both cases, however, extremely valuable infor- mation on vascular status was obtained from the MRI scan, precluding the need for venacavogra- phy. Precise detail with an excellent anatomic per- spective was obvious in both cases presented.
Since surgery is the mainstay of treatment, very accurate preoperative assessment is crucial. MRI scanning can add to the precision of the evaluation and probably preclude the use of venacavography. MRI has also been helpful to us for evaluating when the help of our cardiothoracic colleagues will be necessary. Intraoperatively, we have found the MRI scan to be 100 percent correlative to the anatomic findings.
Marc H. Siegelbaum, M.D. Department of Surgery Division of Urology Saint Joseph Hospital Towson, Maryland 21204
REFERENCES
1. Brennan MF: Cancer of the endocrine system, in: De- Vita VT Jr, Hellman S, and Rosenberg SA, (Eds): Cancer: Prin- ciples and Practice of Oncology, Philadelphia, JB Lipincott, 1982, p. 971-1035.
2. Zeffren J, and Yagoda A: Chemotherapy of adrenal cor- tical carcinoma, in Spiers ASD (Ed): Chemotherapy and Uro- logic Malignancies, New York, Springer Verlag, 1982, p. 1.
3. Falke THM, Peetoom JJ, deRoos A, van de Velde CJH, and Mazer M: Gadolinium-DTPA enhanced MR imaging of intravenous extension of adrenocortical carcinoma. J Com- put Assist Tomogr 12: 331-334, 1988.
4. Smith SM, Patel SK, Turner DA, and Matalon TAS: Magnetic resonance imaging of adrenal cortical carcinoma. Urol Radiol 11: 1-6, 1989.
5. Doty DB, and Baker WH: Bypass of superior vena cava with spiral vein graft. Ann Thorac Surg 22: 490-493, 1976.
6. Ritchey ML, Kinard R, and Novicki E: Adrenal tu- mors: involvement of the inferior vena cava. J Urol 138: 1134-1136, 1987.
7. Bodie B, Novick AC, Pontes JE, Straffon RA, Montie JE, Babiak T, Shoeler L, and Schumacher P: The Cleveland Clinic experience with adrenal cortical carcinoma. J Urol 141: 257-260, 1989.
8. Cahill PJ, and Sukov RJ: Inferior venal caval involve- ment by adrenal cortical carcinoma. Urology 10: 604-607, 1977.
9. Luton JP, Cerdas S. Billaud L, Thomas G, Guilhaume B, Bertagna X, Laudat MH, Louvel A, Chapuis Y, Blondeau P, et al .: Clinical features of adrenocortical carcinoma, prognostic factors, and the effect of mitotane therapy. N Engl J Med 322: 1195-1201, 1990.
10. Barzilay JI, and Pazjanos AG: Adrenocortical carci- noma. Urol Clin North Am 163: 457-468, 1989.
11. Novick AC, Streem SB, and Pontes JE: Stewart’s Oper- ative Urology, Baltimore, Williams & Wilkins, 1989, p. 111.
12. Francis IR, Gross MD, Shapiro B, Korobkin M, and Quint LE: Integrated imaging of adrenal disease, Radiology 184: 1-13, 1992.
EDITORIAL COMMENT
Adrenocortical carcinoma is a rare malignancy with a poor prognosis. It invades adjacent organs in up to 65 percent of cases. Inferior vena cava (IVC), adrenal vein, or renal vein invasion can occur in 25 to 35 percent of cases. Therefore, proper surgical planning for an en bloc excision is critical for a successful outcome. Wide surgical excision is the only treatment that offers any chance of improved survival rates or possible cure. Further improvement in the clinical outcome with adrenocortical carcinoma awaits improved surgical ap- proaches and the development of an effective form of chemotherapy.
New surgical techniques, such as cardiopulmonary bypass, have improved survival rates in patients with adrenocortical carcinoma who have inferior vena cava tumor thrombus in the intrahepatic or suprahepatic IVC. Because the surgical ap- proach can vary dramatically with different levels of IVC
tumor thrombus, it is paramount that accurate diagnostic imaging is used preoperatively.
Computed tomography (CT) scans are done in almost all patients as a part of the diagnostic workup that leads to the diagnosis of adrenocortical carcinoma. CT has dramatically improved the preoperative assessment of patients with adrenocortical carcinoma. However, CT has several limita- tions with regard to staging large malignancies such as adrenocortical carcinoma.
Because adrenocortical carcinomas are often very large at the time of diagnosis, the organ of origin may be difficult to determine on imaging studies. This is particularly true in the left upper quadrant, where these large tumors arise near the pancreas, left kidney, or stomach. Because of the transverse nature of the CT images, it is often difficult to identify the exact origin of these large masses. Proper identification of organ of origin and adjacent organ involvement is made eas- ier with coronal and sagittal images that can be obtained with magnetic resonance imaging (MRI). Sagittal and coronal views allow imaging to occur perpendicular to tissue planes and thus affords a more accurate assessment of adjacent organ involvement. Coronal imaging also allows the surgeon to obtain a more global view of the tumor and adjacent struc- tures as it would appear in surgery.
Vena caval involvement is a significant factor in preopera- tive surgical planning. Vena caval involvement can occur by direct invasion, but it appears to occur more commonly as intraluminal tumor thrombus that extends from the adrenal vein into the left renal vein (if it is a left-sided tumor) and then into the IVC. This is similar to IVC extension seen in renal cell carcinoma. IVC extension can occur at four differ- ent levels: level 1 tumor thrombus occurring only at the entry of the left renal vein (left-sided tumors); level 2 tumor thrombus extending up the IVC but remaining below the entry of the most inferior hepatic vein; level 3 refers to tumor thrombus extending into the intrahepatic vena cava but below the diaphragm; and level 4 refers to tumor thrombus extending above the diaphragm or into the right atrium. All four levels of IVC tumor thrombus require different surgical approaches. Proper identification of the exact level preopera- tively is vital to a successful outcome.
MRI is clearly the examination of choice in the evaluation of IVC tumor thrombus when compared to ultrasound, CT, and inferior venacavography. Because of the ability of the MRI to display images of the IVC in the coronal, sagittal, and axial planes, it can more accurately identify the exact level of tumor thrombus. In addition, MRI has much better inherent tissue contrast, which enables easy and reliable delineation of IVC tumor thrombus. In addition, because it requires no intravenous contrast media, it is safer and more reliable. Fi- nally, because MRI is noninvasive and can relate IVC tumor thrombus to adjacent organs, it is far superior to inferior ve- nacavography.
In summary, adrenocortical carcinomas are rare and diffi- cult tumors to manage. Proper preoperative assessment of local extension and IVC involvement are paramount for a successful outcome. MRI offers the most accurate preopera- tive staging of this difficult tumor and should be performed on all patients undergoing surgical en bloc resection for adrenocortical carcinoma.
Bernard F. King, Jr., M.D. Department of Radiology Mayo Medical School Rochester, Minnesota 55905