What is the Difference Between Pleomorphic Adenoma and Warthin Tumor?

Pleomorphic adenoma and Warthin tumor are both benign tumors that can occur in the parotid gland, but they have some differences in their characteristics and ultrasonographic features. The main differences between pleomorphic adenoma and Warthin tumor include:

1. Shape: Pleomorphic adenomas tend to have a lobulated shape, especially when their diameter exceeds approximately 20 mm. In contrast, Warthin tumors are oval-shaped, even when they have a large size.
2. Vascularization: Warthin tumors have richer vascularization compared to pleomorphic adenomas. In one study, 73.1% of Warthin's tumors had grade 2 or grade 3 vascularity, while 77.9% of pleomorphic adenomas had grade 0 or grade 1 vascularity (P = 0.000).
3. Cystic Areas: Cystic areas within lesions were detected in 16 (20.8%) pleomorphic adenomas and 42 (45.2%) Warthin's tumors (P = 0.001).
4. Histopathological Features: Warthin tumors have a rich capillary network and high cellularity-stromal grade, while pleomorphic adenomas have less angiogenesis but abundant muciform and chondroid tissue.

Ultrasonography and other imaging techniques, such as CT perfusion imaging, can be used to differentiate between pleomorphic adenomas and Warthin tumors based on their vascularization, shape, and other features.

Comparative Table: Pleomorphic Adenoma vs Warthin Tumor

Here is a table comparing the differences between pleomorphic adenoma and Warthin tumor:

The ultrasonographic classification and vascularization are significant differences between pleomorphic adenomas and Warthin tumors, with Warthin tumors more likely to have anechoic areas and higher vascularization grades.