**Core Concept**
Lymphoepithelioma of the parotid gland is a rare salivary gland malignancy characterized by its aggressive behavior and poor prognosis. It is a type of non-keratinizing squamous cell carcinoma, often associated with Epstein-Barr virus (EBV) infection.

**Why the Correct Answer is Right**
Lymphoepithelioma of the parotid gland typically presents with rapid growth, facial nerve involvement, and cervical lymphadenopathy. The tumor cells are large and pleomorphic, with a high nuclear-to-cytoplasmic ratio, and often exhibit intracellular and extracellular mucin production. EBV has been found in the tumor cells of most cases, suggesting a potential role in the pathogenesis of this malignancy.

**Why Each Wrong Option is Incorrect**
**Option A:** Lymphoepithelioma of the parotid gland is not typically associated with a favorable prognosis, which is a key characteristic of this malignancy. This option is incorrect because lymphoepithelioma is known for its aggressive behavior and poor response to treatment.
**Option B:** This option is correct, as lymphoepithelioma of the parotid gland often presents with rapid growth and facial nerve involvement. However, since the question asks for the exception, this option is not relevant.
**Option D:** Lymphoepithelioma of the parotid gland is not typically associated with a good response to radiation therapy, which is a key characteristic of this malignancy. This option is incorrect because lymphoepithelioma is known for its resistance to radiation therapy.

**Clinical Pearl / High-Yield Fact**
Lymphoepithelioma of the parotid gland is a rare but aggressive salivary gland malignancy that often presents with rapid growth and facial nerve involvement. Its association with EBV infection suggests a potential role for viral oncogenesis in the pathogenesis of this malignancy.

**Correct Answer: A. Lymphoepithelioma of the parotid gland is typically associated with a favorable prognosis.**