A 40-year-old man is found to have bilateral adrenal masses and episodic hypertension. Urine catecholamines are elevated. Adrenal tissue removed at surgery shows cells arranged in 'Zellballen' (ball-like nests) with sustentacular cells at the periphery. This histological pattern is characteristic of:
- A Adrenal cortical adenoma
- B Pheochromocytoma ✓
- C Adrenal cortical carcinoma
- D Neuroblastoma
Correct answer: B. Pheochromocytoma
Explanation
Pheochromocytoma (arising from adrenal medullary chromaffin cells) shows the characteristic 'Zellballen' pattern: neoplastic cells arranged in compact nests or balls separated by a rich vascular stroma, with sustentacular (supporting) cells at the periphery of each nest. Cells stain for chromogranin and synaptophysin. Neuroblastoma also arises from the medulla but shows small round blue cells with Homer-Wright rosettes; adrenal cortical tumors lack Zellballen.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.