Fine-Needle Aspiration of an Incidental Pheochromocytoma Mimicking Renal Carcinoma: A Case Report and Review of Safety Considerations

Fine needle aspiration (FNA) of abdominal and intra-abdominal masses has been a safer and well-established procedure associated with minimal risk and low mortality. However, there have been limited reports in the literature regarding aspiration of adrenal masses. Radiologically guided fine-needle aspiration cytology (FNAC) has been performed in patients with malignant diseases or those with suspected adrenal malignancy and metastases. As FNA carries a risk of triggering a hypertensive crisis, it has generally been considered contraindicated in clinically suspected pheochromocytomas. However, the literature indicates that percutaneous tissue sampling of adrenal lesions is infrequent and is performed only selectively; adrenal incidentalomas are detected in ~1-5% of abdominal computed tomography (CT) examinations, while pheochromocytoma incidence is low (≈2-8 cases per million per year) and is present in an estimated 0.1-0.6% of hypertensive patients; therefore, routine FNA of adrenal masses is uncommon. Here, we present a known hypertensive case of an 82-year-old male who presented to the surgery department of our hospital with complaints of headache, urinary discomfort, and dizziness. Radiological findings suggested a suprarenal mass on the superior pole of the kidney that appeared neoplastic in origin. Guided FNAC was advised as clinicians primarily suspected renal carcinoma. FNA smears revealed tumor cells arranged in loosely cohesive clusters and scattered singly. These tumor cells were pleomorphic and showed prominent anisokaryosis, abundant eosinophilic cytoplasm, and intranuclear inclusions. Based on radiological and cytological findings, a diagnosis of pheochromocytoma was suggested and later confirmed histologically. FNA cytology is a low-risk tool that can provide diagnostic and prognostic information. However, due to the potentially fatal risk of hemorrhage and catecholamine release, its application in diagnosing adrenal tumors remains contentious. FNA in cases of pheochromocytoma is not always contraindicated, but aspiration must be conducted with utmost caution in a setting equipped to manage a hypertensive crisis.