**Question:** The following are consistent with pheochromocytoma except -

A. Increased blood pressure
B. Hyperglycemia
C. Increased lipolysis
D. Hypoventilation

**Core Concept:**
Pheochromocytoma is a rare neuroendocrine tumor that originates from chromaffin cells within the adrenal medulla or extra-adrenal paraganglia. These tumors secrete catecholamines, primarily adrenaline and noradrenaline, leading to the characteristic clinical features.

**Why the Correct Answer is Right:**
D. Hypoventilation is not a consistent feature of pheochromocytoma. Pheochromocytomas are typically associated with increased sympathetic stimulation, leading to hypertension (A), hyperglycemia (B), and increased lipolysis (C). Hypoventilation is more commonly seen in patients with central nervous system involvement, such as those with brain tumors or trauma.

**Why Each Wrong Option is Incorrect:**
A. Increased blood pressure (hypertension) is a common feature of pheochromocytoma, as it is a result of excess catecholamine release.
B. Hyperglycemia is another common manifestation of pheochromocytoma due to the stimulation of glucagon release by catecholamines, causing gluconeogenesis and glycogenolysis.
C. Increased lipolysis is attributed to the increased sympathetic tone in pheochromocytoma, leading to elevated levels of free fatty acids and ketones in the blood.

**Clinical Pearl:**
In clinical practice, it is essential to consider pheochromocytoma in patients presenting with unexplained hypertension and consider the differential diagnosis based on additional symptoms and signs. Hypoventilation should prompt further evaluation for central nervous system involvement rather than pheochromocytoma.