Clinical Pearls & Morning Reports
Published December 14, 2022
The risk of having an adrenocortical carcinoma is increased when an adrenal mass is greater than 4 cm in diameter. Read the NEJM Case Records of the Massachusetts General Hospital here.
Q: Describe imaging characteristics that help to distinguish between possible diagnoses for an adrenal mass.
A: Imaging characteristics can be helpful in distinguishing between adrenal adenoma, pheochromocytoma, adrenocortical carcinoma, and adrenal metastasis. Adrenal adenomas are typically round, homogeneous, and relatively small. Pheochromocytomas are typically highly vascular and may show cystic or hemorrhagic changes. Adrenocortical carcinomas are typically unilateral and may be irregular in shape. Adrenal metastases are typically bilateral.
Q: Do adrenal adenomas have a high or a low lipid content?
A: The density of an adrenal mass before the administration of intravenous contrast material can be helpful in distinguishing among the various possible causes. Most adrenal adenomas have a high lipid content and thus have a low density on unenhanced CT (<10 Hounsfield units).
A: Because the incidence of adrenocortical carcinoma is one case per 1 million persons, management is generally based on imperfect evidence. Key considerations are prognosis and the potential role of adjuvant systemic therapy or adjuvant radiation therapy (or both). Local recurrence after surgical resection remains a common issue for patients with adrenocortical carcinoma, with estimated rates as high as 65%. For the initial surgical management of adrenocortical carcinoma, laparoscopic adrenalectomy has been associated with higher rates of local recurrence and worse survival outcomes than open adrenalectomy. Outside clinical trials, adjuvant systemic therapy for adrenocortical carcinoma primarily involves the use of mitotane, a derivative of the insecticide dichlorodiphenyltrichloroethane (DDT). The role of adjuvant radiation therapy in the treatment of adrenocortical carcinoma has been debated, particularly because small, early studies suggested that adrenocortical carcinoma was relatively radioresistant, with adjuvant radiation therapy leading to poor local control rates and increased toxic effects. However, more recent case reports and retrospective analyses have suggested that adjuvant radiation therapy, with or without mitotane therapy, leads to a significant increase in local control.
A: The dosing of mitotane is highly individualized. Treatment usually begins with the administration of a low dose that is slowly increased while the serum drug level is measured and the patient is monitored for clinical side effects. Gastrointestinal, central nervous system, and endocrine side effects are particularly common. The elimination half-life of mitotane is long and variable. The strongest evidence to support the use of adjuvant mitotane therapy comes from a retrospective analysis. Among patients with adrenocortical carcinoma who had undergone surgery, two cohorts received postoperative surveillance and one cohort received adjuvant mitotane therapy. Recurrence-free survival was longer in the mitotane cohort (42 months) than in the two observation cohorts (10 months and 25 months). These data are subject to the limitations of retrospective analyses.