To biopsy or not to biopsy adrenal mass: is that the question?

Abstract

The European Society of Endocrinology recommends surgical approach for suspicious adrenal mass with a limited role for adrenal biopsy. We report here a case of a patient with a 70 mm adrenal mass in whom adrenal biopsy avoided unnecessary adrenalectomy. An 80-year-old man was explored for a 67 × 41 mm suspect left adrenal tumor. Hormonal explorations were normal. 18F-FDG-PET/CT showed an increase in uptake of the adrenal mass (SUVmax: 44.6). As the diagnostic was uncertain, biopsy was performed. Pathology found T lymphocytic inflammatory infiltrate with CD4 phenotype without malignancy criteria. Simple close monitoring was decided in multidisciplinary meeting and with the patient’s consent. At 1 and 3 months, CT and 18F-FDG-PET/CT showed a significant decrease in size and uptake of adrenal mass (40 × 20 mm and 19 × 10 mm and SUVmax 5.9 and 0.0). This report shows the interest of adrenal biopsy for well-selected cases to avoid unnecessary adrenal surgery.

Background

The incidental discovery of an adrenal mass, or incidentaloma, defined as the presence of an adrenal mass ≥1 cm, is a frequent clinical situation (approximately 4%–5% of conventional imaging examinations in adults). ¹ The European Society of Endocrinology recently published guidelines on the management of adrenal incidentalomas. They recommend that surgical approach should be considered for adrenal mass with radiological findings suspicious of malignancy such as lesions >4 cm that are inhomogeneous or have a spontaneous density >20 Hounsfield units (HU). Moreover, they recommend adrenal biopsy only if three key criteria are fulfilled ¹ : the lesion is hormonally inactive (in particular a pheochromocytoma has been excluded), ² the lesion has not been conclusively characterized as benign by imaging, and ³ clinical management of the patient would be altered by knowledge of the histology (in the case of lymphoma for example). ² Adrenal biopsy was rarely useful for diagnosis (even in case of extra adrenal malignancy, lymphoma, sarcoma, and infiltrative or infectious process), at risk of dissemination in case of malignant tumor and at risk of catecholamines discharge in case of pheochromocytoma. Finally, adrenal biopsy should be performed by physicians experienced in this procedure and when it affects management decisions. We report here a case of a patient with a 70 mm adrenal mass in whom adrenal biopsy avoided unnecessary adrenalectomy.

Case presentation

An 80-year-old man was explored for a left adrenal tumor revealed on a CT scan performed for asthenia and biological inflammatory syndrome (C-reactive protein at 45 mg/L). CT scan showed a 67 × 41 mm left adrenal mass with spontaneous density of 39 UH and absolute washout at 5%. Hormonal explorations did not find hypersecretion: 24 h urinary metanephrines and normetanephrine were normal, suppressed cortisol levels by dexamethasone (35 nmol/L), normal level of ACTH (9.2 pmol/l), DHEAS (1381 nmol/L), androgens, and aldosterone. Positron emission tomography with [18F]2-deoxy-D-glucose combined with CT (¹⁸F-FDG-PET/CT) (Fig. 1(a)) showed an increase uptake of the adrenal mass (SUVmax: 44.6), of peritoneal lymphadenopathy and of a right pleuro-diaphragmatic nodule. As the diagnostic was uncertain, the case was discussed in a multidisciplinary expert meeting and a coaxial adrenal biopsy was performed, with patient’s consent, with a 15 cm and 18 gauge needle with the patient in the prone position (Fig. 1(b)). Pathology found T lymphocytic inflammatory infiltrate with the CD4 phenotype without evidence for lymphomatous proliferation (Fig. 1(c)) or malignancy criteria. There was no argument for sarcoidosis or tuberculosis (no granulomatous inflammation). A myelogram was performed and was normal. A complete infectious assessment was carried out and found only positive CMV serology but with negative CMV PCR. Hydatidosis serology was negative. There was no expression of CMV, EBV, or HHV8 on pathology. CT scan was not suggestive of an adrenal hematoma. Given the age of the patient and the absence of diagnosis, closed simple monitoring was decided in the multidisciplinary meeting and with patient’s consent. CT at 2 weeks revealed a spontaneous decrease with a 49 × 26 mm adrenal mass. At 1 and 3 months, CT and 18F-FDG-PET/CT showed a significant decrease in adrenal mass at 40 × 20 mm and 19 × 10 mm and a decrease in uptake (SUVmax 5.9 and 0.0).

Figure 1.

Spontaneous regression of a suspicious left adrenal mass. (a) Axial 18F-FDG-PET/CT section at the beginning, at 1 month and at 3 months. (b) Axial CT section of adrenal biopsy. (c) Pathology of adrenal biopsy enlargement 40 with hematoxylin stain (upper right), CD 20+ (upper left), CD4+ (down right), and CD3+ (down left).

Discussion and conclusions

Adrenal biopsy is not a routine examination in assessment of adrenal tumors. Non-invasive imaging examinations, hormonal tests, and infectious assessment are usually sufficient to determine the nature of the mass and decide on adequate treatment. In our case, we decided to perform an adrenal biopsy due to the absence of hormonal hypersecretion and to precise the diagnosis before surgery. Potential complications of adrenal biopsy are hemorrhage and pneumothorax but remain rare with a complication rate at 1.7%. ² The fear of tumor dissemination due to adrenal biopsy is not justified anymore if the biopsy is carried out by an experienced operator with a secure coaxial needle. We think that it should be considered to avoid unnecessary adrenal surgery and useless morbi-mortality, particularly in this 80-year-old patient. The limit of our report is that we do not have the definitive diagnosis of this adrenal mass. Adrenal pseudotumors described in the literature were secondary to infections such as tuberculosis,^3,4 alveolar echinococcosis, ⁵ or CMV. ⁶ None of these infectious agents were found in our patient. Due to the spontaneous tumor regression and the lymphocytic inflammatory infiltrate in pathology, we nevertheless believe that this pseudotumor was due to an infection without being able to identify the infectious agent in question.

In conclusion, this report shows the interest of adrenal biopsy for well-selected cases to avoid unnecessary adrenal surgery.