Jan. 15, 2021
Adrenal masses are a very common clinical problem, encountered in up to 5% of all patients undergoing cross-sectional imaging. On the other hand, pheochromocytomas are by far less frequent. Historically these rare tumors of the adrenal gland, originating from the adrenal medulla chromaffin cells, were summarized by the "rule of 10" — 10% familial, 10% bilateral, 10% malignant and 10% extra-adrenal.
Recent studies, however, show that in up to 40% of patients, pheochromocytomas are associated with hereditary syndromes such as multiple endocrine neoplasm, type 2; von Hippel-Lindau disease; and others. When related to hereditary syndromes, pheochromocytomas also tend to present in a bilateral manner and are less likely to manifest as a malignant disease compared with sporadic cases.
While medical therapy can stabilize the volatile clinical picture in these patients, surgery remains the only curative option for treating their adrenal tumors. Today, more than 90% of adrenalectomies are performed in a minimally invasive manner.
"Whether the approach is transabdominal, retroperitoneal or robotic, the complication rate is very low when performed by high-volume endocrine surgeons, and when these patients are treated using a multidisciplinary approach," explains Benzon M. Dy, M.D., Endocrine Surgery, at Mayo Clinic in Rochester, Minnesota. Patients with bilateral disease had traditionally been treated by performing bilateral total adrenalectomy, leaving them with lifelong dependence on exogenous corticosteroid replacement alongside recurrent concerns about adrenal insufficiency crisis.
Since most familial cases of pheochromocytoma are less likely to have a malignant potential, it is especially appealing to offer selected patients a cortical-sparing bilateral adrenalectomy, with the rationale of removing the medullary tumor while preserving some cortical adrenal tissue that will keep on producing steroid hormones. This procedure, as opposed to total bilateral adrenalectomy, could spare the dependency of exogenous steroids and the potential lifelong, life-threatening risk of an adrenal crisis.
"Cortical-sparing adrenalectomy has significant implications in quality of life for patients requiring bilateral adrenalectomy," says Dr. Dy. "Although our practice has traditionally aimed to perform total adrenalectomies bilaterally to lower recurrence rate, the quality-of-life data are quite compelling."
Recent data support this evolving approach. In 2019, Neumann and others reported the experience of the European-American-Asian-Bilateral-Pheochromocytoma-Registry, a collaboration of 45 centers from 19 countries. In their cohort of 625 patients with bilateral pheochromocytoma, they investigated the association of pheochromocytoma-specific morbidity and mortality between patients undergoing cortical-sparing adrenalectomies and patients undergoing total bilateral adrenalectomies.
In their report, treatment for 52% of patients with bilateral disease was planned as cortical sparing, which resulted in the development of adrenal insufficiency in only 23.5% of these patients, as opposed to adrenal insufficiency in all patients treated with total bilateral adrenalectomy. In terms of disease recurrence, 13% of the 248 patients treated successfully with cortical-sparing adrenalectomy subsequently developed another pheochromocytoma in the remaining adrenal gland within four to 17 years, as opposed to only two of the 301 patients treated with total bilateral adrenalectomy. All patients were treated successfully with subsequent surgery. They did not demonstrate a difference in terms of pheochromocytoma-related overall survival.
"With recent literature supporting the safety of this approach alongside our collective institutional experience and the appealing results in terms of adrenal insufficiency, we favor this approach of cortical-sparing adrenalectomy in selected patients," concludes Dr. Dy.
For more information
Neumann HPH, et al. Comparison of pheochromocytoma-specific morbidity and mortality among adults with bilateral pheochromocytomas undergoing total adrenalectomy vs. cortical-sparing adrenalectomy. JAMA Network Open. 2019;2:e198898.