Objective: To report a rare case of an adenomatoid tumor (AT) of the adrenal gland.

Methods: We present a case report, including clinical, radiologic, and pathologic findings, and review the relevant literature.

Results: We describe a 60-year-old man in whom an AT of the adrenal gland was discovered incidentally, and review the literature. Fewer than 20 cases of these tumors are reported. The tumors range in size from 0.5 to 11 cm, are more common in men, and are more frequently located in the left adrenal gland. A specific imaging phenotype has not been characterized. Histologic features, including infiltration into the surrounding tissue, and presence of signet ring cells, may raise concern of a more aggressive neoplasm. Immunologic staining for mesothelial and endothelial markers may be necessary to establish a definitive diagnosis.

Conclusion: ATs of the adrenal gland are rare benign lesions. They are difficult to differentiate from more common adrenal tumors by computerized tomography (CT) or magnetic resonance imaging (MRI). Pathologic findings also can present challenges in distinguishing these lesions from more aggressive neoplasms. ATs should be considered in the differential diagnosis of adrenal masses, whether discovered as incidental radiologic, surgical, or pathologic findings, or at autopsy, so that the potential consequences of misdiagnosis may be avoided.