**Core Concept**
Herpes simplex encephalitis (HSE) is a rare but serious condition caused by the herpes simplex virus (HSV), typically affecting the temporal lobes of the brain. In immunocompromised patients, such as those undergoing chemotherapy for leukemia, HSE can occur more frequently due to impaired immune function.

**Why the Correct Answer is Right**
In HSE, the herpes simplex virus infects the neurons and causes inflammation in the brain. A CT scan of the patient's brain would likely show areas of low attenuation (hypodensity) indicating edema and necrosis in the temporal lobes, particularly in the medial and inferior surfaces. This is due to the viral replication and subsequent inflammatory response in the brain parenchyma.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because HSE typically involves the temporal lobes, not the frontal lobes.
* **Option B:** This option is incorrect because while HSE can cause hemorrhage, it is not the most characteristic finding on a CT scan.
* **Option C:** This option is incorrect because while HSE can cause edema, it is not typically described as "bilateral frontal" edema.

**Clinical Pearl / High-Yield Fact**
In immunocompromised patients, such as those undergoing chemotherapy, HSE can be a life-threatening complication. Prompt diagnosis and treatment with antiviral medications, such as acyclovir, are essential to prevent neurological deterioration.

**Correct Answer:** C.