C. Pleomorphic Adenoma

Pleomorphic adenoma:

A benign salivary gland tumor that exhibits wide cytomorphologic and architectural diversity of epithelial and mesenchymal components (mixed tumor). Often seen in the parotids as a solitary slow growing, painless, firm nodular mass. 

Key Questions & Answers 

1. Is pleomorphic adenoma an example of benign or malignant tumor?

It is a benign tumor

2. What are the sites you see pleomorphic adenoma?

Pleomorphic adenomas are seen in the parotid gland, submandibular gland and minor salivary glands.

3. Why does it recur after surgery in some cases?

As the tumor is partially encapsulated and is expansile it produces protrusions into the surrounding gland which may lead to recurrence if the tumor is merely enucleated.