Miscellaneous adrenal neoplasms (Cysts, myelolipoma, hemangioma, lymphangioma)

Abstract

Adrenal neoplasms that are non-functional and have benign characteristics on imaging studies may pose a management dilemma. This is particularly true of the uncommon neoplasms that have an uncertain natural history. These tumors usually present as adrenal incidentalomas, with an incidence of 1-4% on imaging studies.With liberal computed tomography (CT) scanning and advanced imaging techniques, they are becoming a more frequent entity.While the majority of adrenal incidentalomas are adenomas or metastases [14], this chapter will focus on the diagnosis and management of the less common adrenal neoplasms. The best studies to obtain to aid in the diagnosis of these neoplasms are CT scanning and magnetic resonance imaging (MRI).A non-enhanced CT scan is the most common modality used in adrenal imaging. Density criteria are used to assist in characterizing the adrenal pathology.The helical scanning techniques using smaller slices (3 mm) have improved the accuracy in assessing density. MRI with chemical shift imaging has excellent contrast resolution, allowing imaging of tumors as small as 0.5 cm.The T1-weighted images are the best for assessing anatomic detail.Accurate imaging and interpretation of these neoplasms is critical because the majority are clinically benign and do not require an operation. If an operation is recommended; the patient can usually undergo a laparoscopic adrenalectomy. An open adrenalectomy should be performed if there is any suspicion for a primary malignancy. The role of fine-needle aspiration for cytology is limited secondary to sparse cellularity. Prior to any surgical or other invasive procedure (aspiration), the lesion must be evaluated for function. Functional studies should include a 24-h urine for cortisol, metanephrines, catecholamines and vanillylmandelic acid to assess for either a cortisol-producing neoplasm or a pheochromocytoma. A serum potassium level and possibly an aldosterone level should be obtained to screen for an aldosterone-producing tumor.