Most common primary malignant tumour of parotid gland
**Core Concept**
The parotid gland is a major salivary gland located in the face, and primary malignant tumors of this gland are relatively rare. The most common type of tumor in the parotid gland can be either benign or malignant, but when considering malignant tumors, there is a dominant type.
**Why the Correct Answer is Right**
The most common primary malignant tumor of the parotid gland is adenocarcinoma, specifically the mucoepidermoid carcinoma. Mucoepidermoid carcinoma arises from the salivary gland tissue and is characterized by the presence of both mucous and epidermoid cells. It is a malignant tumor that can range from low to high grade, with the high-grade tumors being more aggressive and having a poorer prognosis. The exact mechanism of mucoepidermoid carcinoma is not fully understood, but it is thought to arise from the malignant transformation of salivary gland cells.
**Why Each Wrong Option is Incorrect**
**Option A:** (no answer provided) - This option is not relevant to the question.
**Option B:** Pleomorphic adenoma - This is a benign tumor, not malignant.
**Option C:** Warthin tumor - This is a benign tumor, not malignant.
**Clinical Pearl / High-Yield Fact**
Mucoepidermoid carcinoma is the most common primary malignant tumor of the parotid gland, and it is essential to differentiate it from other types of salivary gland tumors, such as benign mixed tumors (pleomorphic adenomas) and Warthin tumors, which are benign.
**Correct Answer: C. Warthin tumor is a benign tumor of the parotid gland.