Adrenal Incidentalomas
Adrenal Incidentalomas
Objective: To evaluate the cause and the clinical and laboratory features of adrenal incidentalomas (AI) in 52 patients and to assess the evolution of nonsurgically treated lesions during long-term follow-up.
Methods: We retrospectively analyzed the medical records of 52 patients with AI undergoing routine follow-up in 2 Brazilian endocrine centers.
Results: In our study group, nonfunctioning adenomas were the most frequent cause of AI (42%), followed by cortisol-secreting adenomas (15%), metastatic disease (10%), pheochromocytomas (8%), myelolipomas (6%), cysts (6%), carcinomas (4%), lymphomas (4%), tuberculosis (4%), and aldosteronoma (2%). Only 13 lesions (25%) were functioning (8 cortisol-secreting adenomas, 4 pheochromocytomas, and 1 aldosteronoma). Carcinomas were the largest adrenal masses (mean diameter, 11.7 ± 1.3 cm). With the exception of 1 pheochromocytoma, 1 cyst, and 1 myelolipoma, all AI larger than 6 cm were carcinomas. During follow-up of 21 patients with nonsurgically treated AI for 6 to 36 months (mean, 24.8 ± 8.9), no patient had tumor reduction or disappearance. After 12 months of follow-up, however, a 45-year-old woman had adrenal mass enlargement from 3.2 cm to 4.4 cm; the excised lesion proved to be an adenoma. Moreover, evidence of cortisol hypersecretion developed after 24 months of follow-up in a 30-year-old man with a 3.5-cm adenoma in the left adrenal gland.
Conclusion: Our findings demonstrate that most AI are nonfunctioning benign lesions and emphasize the need for long-term follow-up of patients with conservatively managed lesions, in light of the potential for evolution to hormonal hypersecretion or tumor growth.
Adrenal incidentalomas (AI) are adrenal masses, generally 1 cm or more in diameter, that are discovered serendipitously during a radiologic examination performed for indications other than evaluation of adrenal diseases. Initially described more than 2 decades ago, AI are becoming a common clinical problem with the more frequent use of various imaging techniques. Moreover, they pose a challenging management dilemma because they may be a benign clinical finding or be associated with high rates of morbidity and mortality because of their hormonal activity or malignant histologic features. Most such tumors, however, are benign and hormonally inactive. Although several approaches have been recommended for evaluation of AI, including strategies for hormonal screening, radiologic testing, and histopathologic examination, they are still controversial.
The exact prevalence of AI is difficult to determine. In different published series, it has varied on the basis of the methods and circumstances of detection (that is, the reasons for the imaging study) as well as the age of the patients. In autopsy series, the prevalence of previously undiagnosed adrenal masses has ranged from 1.4% to 8.7%. Among patients screened with ultrasonography, the prevalence of adrenal masses has varied from 0.1% to 0.5%. In large computed tomographic (CT) studies, the prevalence of unexpected adrenal masses has ranged from 0.6% to 4.4%.
The prevalence of adrenal masses identified at autopsy increases from less than 1% among persons younger than 30 years to about 7% in those 70 years of age or older. The prevalence of AI also varies with the age of the patient, being higher in older subjects. Indeed, it approaches 3% in middle-aged patients and increases to as much as 10% in those who are elderly. Other studies have shown that 60% of cases of AI occur between the sixth and the eighth decades of life, at a mean age of 56 ± 12.9 years.
Adrenal incidentalomas may be unilateral or, less frequently, bilateral (11% to 16% of cases). In a review of 9 studies, their underlying diagnoses were as follows: adenomas 41%, metastatic lesions 19%, adrenocortical carcinomas 10%, myelolipomas 9%, and pheochromocytomas 8%, with other lesions (primarily benign) such as adrenal cysts constituting the remainder. This distribution is similar to that reported in the largest study published thus far, which included 1,004 patients, except that this large study found more adenomas and fewer metastatic lesions. Cortisol-secreting adenomas are the most common cause of functioning AI, followed by pheochromocytomas and aldosteronomas. Overall, cortisol-secreting adenomas have been found in 5% to 47% of patients with AI, whereas the prevalence of pheochromocytomas and aldosteronomas ranged from 1.5% to 23% and from 1.6% to 3.8%, respectively.
The main objectives of the current study were to evaluate the cause and the clinical and laboratory features of AI in 52 patients and to assess the evolution of nonsurgically treated lesions during long-term follow-up.
Objective: To evaluate the cause and the clinical and laboratory features of adrenal incidentalomas (AI) in 52 patients and to assess the evolution of nonsurgically treated lesions during long-term follow-up.
Methods: We retrospectively analyzed the medical records of 52 patients with AI undergoing routine follow-up in 2 Brazilian endocrine centers.
Results: In our study group, nonfunctioning adenomas were the most frequent cause of AI (42%), followed by cortisol-secreting adenomas (15%), metastatic disease (10%), pheochromocytomas (8%), myelolipomas (6%), cysts (6%), carcinomas (4%), lymphomas (4%), tuberculosis (4%), and aldosteronoma (2%). Only 13 lesions (25%) were functioning (8 cortisol-secreting adenomas, 4 pheochromocytomas, and 1 aldosteronoma). Carcinomas were the largest adrenal masses (mean diameter, 11.7 ± 1.3 cm). With the exception of 1 pheochromocytoma, 1 cyst, and 1 myelolipoma, all AI larger than 6 cm were carcinomas. During follow-up of 21 patients with nonsurgically treated AI for 6 to 36 months (mean, 24.8 ± 8.9), no patient had tumor reduction or disappearance. After 12 months of follow-up, however, a 45-year-old woman had adrenal mass enlargement from 3.2 cm to 4.4 cm; the excised lesion proved to be an adenoma. Moreover, evidence of cortisol hypersecretion developed after 24 months of follow-up in a 30-year-old man with a 3.5-cm adenoma in the left adrenal gland.
Conclusion: Our findings demonstrate that most AI are nonfunctioning benign lesions and emphasize the need for long-term follow-up of patients with conservatively managed lesions, in light of the potential for evolution to hormonal hypersecretion or tumor growth.
Adrenal incidentalomas (AI) are adrenal masses, generally 1 cm or more in diameter, that are discovered serendipitously during a radiologic examination performed for indications other than evaluation of adrenal diseases. Initially described more than 2 decades ago, AI are becoming a common clinical problem with the more frequent use of various imaging techniques. Moreover, they pose a challenging management dilemma because they may be a benign clinical finding or be associated with high rates of morbidity and mortality because of their hormonal activity or malignant histologic features. Most such tumors, however, are benign and hormonally inactive. Although several approaches have been recommended for evaluation of AI, including strategies for hormonal screening, radiologic testing, and histopathologic examination, they are still controversial.
The exact prevalence of AI is difficult to determine. In different published series, it has varied on the basis of the methods and circumstances of detection (that is, the reasons for the imaging study) as well as the age of the patients. In autopsy series, the prevalence of previously undiagnosed adrenal masses has ranged from 1.4% to 8.7%. Among patients screened with ultrasonography, the prevalence of adrenal masses has varied from 0.1% to 0.5%. In large computed tomographic (CT) studies, the prevalence of unexpected adrenal masses has ranged from 0.6% to 4.4%.
The prevalence of adrenal masses identified at autopsy increases from less than 1% among persons younger than 30 years to about 7% in those 70 years of age or older. The prevalence of AI also varies with the age of the patient, being higher in older subjects. Indeed, it approaches 3% in middle-aged patients and increases to as much as 10% in those who are elderly. Other studies have shown that 60% of cases of AI occur between the sixth and the eighth decades of life, at a mean age of 56 ± 12.9 years.
Adrenal incidentalomas may be unilateral or, less frequently, bilateral (11% to 16% of cases). In a review of 9 studies, their underlying diagnoses were as follows: adenomas 41%, metastatic lesions 19%, adrenocortical carcinomas 10%, myelolipomas 9%, and pheochromocytomas 8%, with other lesions (primarily benign) such as adrenal cysts constituting the remainder. This distribution is similar to that reported in the largest study published thus far, which included 1,004 patients, except that this large study found more adenomas and fewer metastatic lesions. Cortisol-secreting adenomas are the most common cause of functioning AI, followed by pheochromocytomas and aldosteronomas. Overall, cortisol-secreting adenomas have been found in 5% to 47% of patients with AI, whereas the prevalence of pheochromocytomas and aldosteronomas ranged from 1.5% to 23% and from 1.6% to 3.8%, respectively.
The main objectives of the current study were to evaluate the cause and the clinical and laboratory features of AI in 52 patients and to assess the evolution of nonsurgically treated lesions during long-term follow-up.