**Core Concept**
Squamous cell carcinoma of the esophagus often presents with severe malnutrition due to dysphagia, leading to weight loss and hypoalbuminemia. Total parenteral nutrition (TPN) is initiated to support nutritional needs before surgery, but its implementation is associated with specific complications.

**Why the Correct Answer is Right**
In this scenario, the patient is at risk of refeeding syndrome, a potentially fatal condition that occurs when fasting individuals are re-fed too quickly, leading to shifts in electrolytes and fluid balance. This is particularly concerning in severely malnourished patients with low albumin levels, as seen in this patient. The key is to gradually reintroduce nutrients to avoid precipitating refeeding syndrome.

**Why Each Wrong Option is Incorrect**
**Option A:** Hyperglycemia is a concern in TPN, but it is not the most immediate concern in this patient's scenario.
**Option B:** Hypocalcemia can occur in TPN, but it is not as directly related to the initiation of TPN in a severely malnourished patient as refeeding syndrome.
**Option C:** Electrolyte imbalances are common in TPN, but they are not the most pressing concern in this patient's case.

**Clinical Pearl / High-Yield Fact**
To prevent refeeding syndrome, it's essential to gradually reintroduce nutrients over 12-24 hours, and to closely monitor for signs of electrolyte imbalances, such as hypophosphatemia, hypokalemia, and hypomagnesemia.

**Correct Answer:** C.