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Discussion

Adrenal oncocytic neoplasm

Adrenal oncocytic neoplasms (AONs) represent a type of adrenal cortical tumor. Based on the 2022 WHO classification of adrenal cortical tumors, use of the term "oncocytoma" is not recommended. Pathologically, AONs are composed of oncocytes, which are large cells with abundant granular eosinophilic cytoplasm and central pyknotic nuclei. AONs are extremely rare, with only 147 reported cases based on a review from 2013. There is no particular age predilection. AONs are more common in females and in the left adrenal gland. They are most commonly discovered as incidentalomas. Although generally benign and nonfunctioning, 20% of AONs show malignant elements, and 17% of them are functional. In the presented case, bloodwork revealed elevated levels of dehydroepiandrosterone sulfate and normetanephrine.

The imaging features of AONs are overall nonspecific. AONs may be homogeneous or heterogeneous in density, regardless of their malignant nature. Enhancement can also be homogeneous or heterogeneous. They may or may not meet the contrast washout threshold for adenomas. The average Hounsfield unit on unenhanced CT is over 10, and the intrinsic signal intensity on MRI is similar to the spleen on both T1- and T2-weighted images. There is no macroscopic or microscopic lipid. A fibrous capsule may be seen. An important feature of AONs is their large size. Despite their benignity in most cases, the average diameter is 8 cm, similar to the size of adrenocortical carcinomas. Malignant AONs may show hemorrhage and/or necrosis.

Adrenalectomy is the standard management for both definitive diagnosis and treatment. Malignant lesions have a poor five-year survival rate of 20% to 35%, but the survival rate is higher at 50% to 60% if successfully resected.

References

  1. Schieda N, Siegelman ES. Update on CT and MRI of adrenal nodules. AJR Am J Roentgenol. 2017;208(6):1206-1217.
  2. Tirkes T, Gokaslan T, McCrea J, et al. Oncocytic neoplasms of the adrenal gland. AJR Am J Roentgenol. 2011;196(3):592-596.
  3. Mete O, Erickson LA, Juhlin CC, et al. Overview of the 2022 WHO classification of adrenal cortical tumors. Endocr Pathol. 2022;33(1):155-196.
  4. Mearini L, Del Sordo R, Costantini E, Nunzi E, Porena M. Adrenal oncocytic neoplasm: A systematic review. Urol Int. 2013;91(2):125-133.
  5. Bharwani N, Rockall AG, Sahdev A, et al. Adrenocortical carcinoma: The range of appearances on CT and MRI. AJR Am J Roentgenol. 2011;196(6):W706-W714.
  6. Elazime Z, Elazizi L, Aynaou H, Salhi H, Elouahabi H. Oncocytic tumors: An uncommon benign adrenal gland lesions with features of malignancy. Cureus. 2023;15(1):e33638.
  7. Dong D, Liu X, Ji Z, Li H. Diagnosis and treatment of adrenocortical oncocytoma: Case report of five cases and review of the literature. Front Oncol. 2019;9:338.
  8. Hong Y, Hao Y, Hu J, Xu B, Shan H, Wang X. Adrenocortical oncocytoma: 11 case reports and review of the literature. Medicine (Baltimore). 2017;96(48):e8750.
  9. Coppola M, Romeo V, Verde F, et al. Integrated imaging of adrenal oncocytoma: A case of diagnostic challenge. Quant Imaging Med Surg. 2019;9(11):1896-1901.
  10. Mayo-Smith WW, Song JH, Boland GL, et al. Management of incidental adrenal masses: A white paper of the ACR Incidental Findings Committee. J Am Coll Radiol. 2017;14(8):1038-1044.
Our appreciation is extended to Dr. Hwan Lee, University of Pennsylvania Department of Radiology, for contributing this case.