Adrenocortical Oncocytoma: Case Report and Review of the Literature

Adrenocortical oncocytic neoplasm: A systematic review

BACKGROUND

Adrenocortical oncocytic neoplasms are rare tumors, generally regarded as benign and hormonally nonfunctional. We performed a systematic review to update the literature on adrenocortical oncocytic neoplasms by reviewing patient and tumor characteristics, as well as management trends, because the literature is composed of predominately single-case reports.

METHODS

A systematic search was performed in PubMed, Embase, and Cochrane Library through June 2017. Malignant potential was determined by applying the Lin-Weiss-Bisceglia criteria to cases.

RESULTS

Included for analysis were 84 citations describing 140 adrenocortical oncocytic neoplasms, including our own case. These were diagnosed predominantly in females (66%), on the left side (64%), and were nonfunctional (66%). Average age at diagnosis was 44 years (2.5-77), and median tumor size was 80 mm (16-285). A total of 35% of adrenocortical oncocytic neoplasms were benign, 41% borderline, and 24% malignant. Male patients were more likely to have a malignant tumor compared with females (36% versus 18%, P = .035). The 5-year overall survival for benign adrenocortical oncocytic neoplasms was 100%, borderline 88%, and malignant 47%. Hormonal function did not discriminate malignant from benign lesions. Adrenocortical oncocytic neoplasms that stained positive for synaptophysin (50%, P < .001) and negative for vimentin (62%, P = .009) are more often benign.

CONCLUSION

We found that the majority of adrenocortical oncocytic neoplasms (65%) were either malignant or had malignant potential, contrary to the previous literature. The Lin-Weiss-Bisceglia criteria are useful in identifying those patients for whom closer surveillance is warranted, because their prognosis is dependent on the Lin-Weiss-Bisceglia diagnosis.

Adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy, often with an unfavorable prognosis. Here we summarize the knowledge about diagnosis, epidemiology, pathophysiology, and therapy of ACC. Over recent years, multidisciplinary clinics have formed and the first international treatment trials have been conducted. This review focuses on evidence gained from recent basic science and clinical research and provides perspectives from the experience of a large multidisciplinary clinic dedicated to the care of patients with ACC.

Subclinical Cushing's syndrome associated with an adrenocortical oncocytoma

Oncocytoma is a neoplasm that can arise in several organs, and it has been more commonly described in the kidney, salivary gland and thyroid. Oncocytoma arising in the adrenal gland is a rare finding. Moreover, functioning adrenocortical oncocytoma is exceptionally rare. A 47-yr-old man was incidentally discovered to have a right adrenal mass. The patient had no clinical features suggestive of increased adrenal function. However, hormonal evaluation showed a disturbed cortisol circadian rhythm, supranormal urinary cortisol excretion, a low level of ACTH, and a lack of suppressibility of cortisol secretion after dexamethasone. Right adrenalectomy was performed, and this revealed a well-circumscribed dark-brown tumor that measured 2.4x2.2 cm. The tumor consisted almost exclusively of large eosinophilic and epitheloid cells whose cytoplasm was packed with eosinophilic granulations, which corresponded to the numerous mitochondria confirmed on electron microscopy. This is a rare case of subclinical Cushing's syndrome that was caused by adrenocortical oncocytoma.

Functioning adrenocortical oncocytoma: the first documented case producing interleukin-6 and review of the literature

Adrenocortical oncocytoma is an extremely rare and predominantly non-functioning tumor. We herein report the first case of an adrenocortical oncocytoma that produces interleukin (IL)-6. A 38-yr-old woman was referred for treatment of a 4-cm adrenal mass. Laboratory test results showed elevated inflammatory parameters. Intriguingly, IL-6 serum level was also high at 30 pg/ml (normal 0-4 pg/ml). The patient underwent laparoscopic right adrenalectomy. Microscopic examination showed that the tumor was an adrenocortical oncocytoma with a unique peripheral lymphoid cuff with germinal centers. Electron microscopy demonstrated that the cytoplasm of the neoplastic cells was packed with numerous abnormal mitochondria. Three observations lead us to consider that this tumor was the primary source of serum IL-6. First, the IL-6 level in blood collected from the right adrenal vein was highest (527 pg/ml) among intra-operative blood samples. Second, neoplastic cells stained positively for IL-6. Third, the serum IL-6 returned to normal levels immediately after surgery.

Adrenocortical Oncocytoma — A Rare Tumor of Undefined Malignant Potential: Report of a Case

Adrenocortical oncocytomas are exceptionally rare. To our knowledge, only 23 cases have been reported in the world literature, most of which were benign and nonfunctioning. We report a case of adrenocortical oncocytoma diagnosed by pathological examination of an extirpated right adrenal mass in a young woman. We discuss this case and review the literature on this unusual entity.

Functioning adrenocortical oncocytoma: a case report and review of the literature

Adrenocortical oncocytoma is exceptionally rare. Most of these tumors are benign and nonfunctioning. We report a case of functioning adrenocortical oncocytoma located in the right adrenal gland in a 53-year-old woman who presented with Cushing's syndrome. The tumor was small, with exclusively oncocytic histologic features. A discussion of this case and a review of the literature on this entity is presented.

Adrenocortical oncocytic tumors: report of 10 cases and review of the literature

Ten additional adrenocortical oncocytic tumors are presented: 2 benign oncocytomas, 4 borderline oncocytomas of uncertain malignant potential, and 4 oncocytic carcinomas. Histologically all tumors were entirely or predominantly composed of oncocytes. Immunohistochemically all tumors were immunoreactive for mitochondrial antigen mES-13. Electron microscopy was performed in 8 cases and was confirmatory of the oncocytic cell change. The morphologic parameters of the Weiss system, considered to be predictive of the biologic behavior of conventional (nononcocytic) adrenocortical tumors, are reviewed in the context of their possible application to the oncocytic tumor variant. Proposed major criteria (high mitotic rate, atypical mitoses, venous invasion) and minor criteria (large size and huge weight, necrosis, capsular invasion, sinusoidal invasion) in distinguishing malignant tumors are discussed, and definitional criteria (predominantly cells with eosinophilic and granular cytoplasm, high nuclear grade, diffuse architectural pattern) in common with all types of oncocytic tumors are outlined. The authors' proposed working rules for diagnostic categorization of oncocytic adrenocortical tumors are defined, with the presence of 1 major criterion indicating malignancy, 1 to 4 minor criteria indicating uncertain malignant potential (borderline), and the absence of all major and minor criteria indicative of benignancy. Using these criteria, the diagnosis of malignancy was straightforward in 3 of the 4 cases designated as oncocytic carcinoma (presence of at least 2 major criteria and all the minor criteria), while in 1 case the original diagnosis of benign oncocytoma was reversed to malignant following critical review of the original pathologic material after local tumor recurrence. Tumor recurrence occurred in 2 carcinomas at 8 and 20 months, respectively, and was followed in 1 case by the patient's death. The third patient expired at 6 months from unrelated causes, and the fourth patient is free of disease at the relatively short follow-up interval of 6 months. Regarding the 4 patients with borderline tumors, all are alive with no evidence of disease, with follow-up ranging from 10 to 61 months (mean 38.7 months). The 2 benign tumors have a follow-up of 25 and 30 months, respectively. Diagnostic difficulties are delineated and a complete review of the literature on this topic has also been performed.

Oncocytic adrenocortical carcinomas: a pathological and immunohistochemical study of four cases in comparison with conventional adrenocortical carcinomas

Clinicopathological features of four cases of oncocytic adrenocortical carcinomas were studied. All tumors were large, circumscribed tumors with average size and weight of 11.5 cm and 586 g, respectively. The cut surfaces were yellow or brown and tan with areas of hemorrhage, necrosis, fibrosis, myxoid and cystic change. The tumor cells were exclusively oncocytic with a diffuse or compact and solid arrangement. Nuclear atypia was identified but mitosis was rare. Capsular invasion was identified in all tumors and vascular invasion was identified in one tumor. All tumors were immunoreactive for vimentin and inhibins. Immunoreactivity for pancytokeratin, synaptophysin and S-100 protein was variable and focal. All tumors had low proliferative indices, of less than 1%, and were negative for p53 protein. Ultrastructurally, the cytoplasm of tumor cells showed numerous mitochondria in a compact arrangement. Oncocytic adrenocortical carcinomas showed a similar sex ratio, slightly older mean age, similar left predilection, slightly smaller size and lighter weight compared with the conventional carcinomas. We suggest that most oncocytic adrenocortical carcinomas might be low-grade malignancies with less aggressive histological features compared with conventional carcinomas. However, they should be excised completely because of the likelihood of recurrence and metastasis during the follow-up period.

Adrenocortical oncocytoma

We report the case of an adrenocortical oncocytoma of the left adrenal cortex in a young woman. Physical examination revealed a mass in the left upper quadrant of the abdomen using abdomen ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI), which allowed the identification of a large and inhomogeneous mass between the left kidney and the spleen. The lesion was not endowed of any specific radiologic characteristic nor bysided by any biochemical activity that could allow a radiological presurgical diagnosis. Surgical resection led to the diagnosis of adrenocortical oncocytoma, with no aspects revealing malignant potential.

[Adrenocortical tumors with oncocytic cells: benign or malignant?]

Adrenocortical tumor with oncocytic cells are exceptional. They are composed exclusively or almost exclusively of oncocytic cells, which are large cells with eosinophilic granulations, corresponding to numerous mitochondria in electronic microscopic examination. This tumor is usually non-functional and benign, and has to be differentiated from the adrenocortical carcinoma.

Management approaches to adrenal incidentalomas. A view from Ancona, Italy

The definition of adrenal incidentaloma encompasses a heterogeneous spectrum of pathologic entities, including primary adrenocortical and medullary tumors, benign or malignant lesions, hormonally active or inactive lesions, metastases, and infections. This article provides an overview of the diagnostic clinical approach and management of the incidentally discovered adrenal masses. Approaches are based on data collected in more than 1000 cases of the Collaborative Study Group on Adrenal Incidentaloma of the Italian Society of Endocrinology and the authors' experience.