Pheochromocytoma

Partial or complete adrenalectomy is recommended in patients with MEN types IIA and IIB who are found to have a pheochromocytoma. It is important to medically stabilize the patient prior to surgery to avoid any perioperative events owing to excessive catechol secretion. Preoperative alpha-blockade is achieved by administration of phenoxybenzamine (40 to 200 mg/day) for 5 days to 2 weeks prior to surgery. The dose is titrated to the lowest blood pressure tolerated by these patients without symptomatic relative hypotension. Should tachycardia or cardiac arrhythmia result from treatment with phenoxyben-zamine, a ß-blocker is added to the treatment regimen. After medical stabilization, the patient is taken for operation. During the procedure, it may be necessary to control intraoperative paroxysmal hypertension with short-acting antihypertensives such as sodium nitroprusside or phentolamine.

Traditionally, controversy has existed as to whether unilateral or bilateral adrenalectomy should be performed for unilateral tumors. In a series at our institution, the results of unilateral and bilateral adrenalectomies were compared.21 Nearly one-quarter of patients undergoing bilateral adrena-lectomy experienced at least one episode of acute adrenal insufficiency requiring hospitalization. Two of these patients died from episodes of adrenal insufficiency. Of the patients who had unilateral adrenalectomies, 52% developed contralateral pheochromocytomas after a mean interval of 12 years. Conversely, 48% of patients remained disease free by biochemical and symptomatic standards during a mean interval of 5 years. Based on these results, it is our practice to perform resection

Figure 17-11. A, Computed tomographic (CT) scan of the liver of a patient with multiple endocrine neoplasia type IIA, recurrent medullary thyroid carcinoma (MTC), and elevated calcitonin levels. There is no evidence of liver metastases on the scan. B, Laparoscopic view of the liver of the same patient showing multiple small raised whitish lesions on and just beneath the surface of the liver, confirmed to be metastatic MTC by biopsy. These small multiple metastases (arrows) are often not seen on routine CT scanning or other imaging modalities, including nuclear scanning. Reproduced with permission from Tung WS et al.19

Figure 17-11. A, Computed tomographic (CT) scan of the liver of a patient with multiple endocrine neoplasia type IIA, recurrent medullary thyroid carcinoma (MTC), and elevated calcitonin levels. There is no evidence of liver metastases on the scan. B, Laparoscopic view of the liver of the same patient showing multiple small raised whitish lesions on and just beneath the surface of the liver, confirmed to be metastatic MTC by biopsy. These small multiple metastases (arrows) are often not seen on routine CT scanning or other imaging modalities, including nuclear scanning. Reproduced with permission from Tung WS et al.19

Figure 17-12. Coronal magnetic resonance image showing left-sided jugular nodal metastases (arrows) (levels III and IV) from medullary thyroid carcinoma (MTC) in a patient with multiple endocrine neoplasia type IIA many years after total thyroidectomy for MTC. Calcitonin levels are now elevated. Reproduced with permission from Moley JF, Lairmore TC, Phay JE. Hereditary endocrinopathies. Curr Probl Surg 1999;36:653-764.

Figure 17-12. Coronal magnetic resonance image showing left-sided jugular nodal metastases (arrows) (levels III and IV) from medullary thyroid carcinoma (MTC) in a patient with multiple endocrine neoplasia type IIA many years after total thyroidectomy for MTC. Calcitonin levels are now elevated. Reproduced with permission from Moley JF, Lairmore TC, Phay JE. Hereditary endocrinopathies. Curr Probl Surg 1999;36:653-764.

of the involved adrenal only and maintain yearly biochemical screening thereafter.

The classic surgical approach for adrenalectomy in MEN type II patients is through an anterior abdominal midline incision. The first report of successful laparoscopic removal of adrenal tumors was by Gagner and colleagues in 1992.22 Since then, several studies have demonstrated the safety and efficacy of laparoscopic adrenalectomy for benign adrenal neoplasms. Patients with MEN types IIA and IIB may be ideally suited to the laparoscopic approach because the pheochromocytomas arising in these syndromes are rarely malignant and almost never extra-adrenal. Pheochromocytomas may be successfully removed by unilateral or bilateral laparoscopic adrenalectomy provided that the adrenal tumors are small, confined to the adrenal gland(s), and accurately localized preoperatively by high-resolution CT or MRI and the patient is adequately prepared pharmacologically. Laparoscopic adrenalectomy is associated with shorter hospital stay, decreased postoperative pain, and more rapid recovery when compared with open adrenalec-tomy.23,24 Contraindications to the laparoscopic approach include large tumors (> 8 to 10 cm), malignant pheochromocytomas, and existing contraindications to laparoscopy.

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