Table 2.

Summary of key points in differential diagnosis of salivary Warthin-like MEC, MEC with TALP and mWT.

	Tumor genesis	Tumor parenchyma				Tumor mesenchymal	Molecular signature
		structure	Oncocytic Cell	Epidermoid cell	Mucus cell	Lymphocytes	Mucus extravasation
Warthin-like MEC MEC	excretory ducts	glandular architecture with cystic structures	The diversity of cystic lining epithelial and the transition zone between the disorganized bi-layered oncocytic epithelium and mono-/multi-layered oncocytic epithelium appeared	Epidermoid	Mucus- producing cells	Dense lymphocytic infiltrate with lymphoid follicle	occur	CRTC1/3-MAML2 rearrangement
MEC with TALP		Solid or cystic structures	Lack the diversity of cystic lining oncocytic epithelium
mWT	excretory ducts	Papillary architecture	Typical bi-layered oncocytic cells.	Focal Nonkeratinized squamoid cells	mucoid metaplasia accompanied with necrosis, haemorrhages and fibrosis.	Dense lymphocytic infiltrate with lymphoid follicle	absent	Non-specific

Note MEC: mucoepidermoid carcinoma, TALP: Tumor-associated lymphoid proliferation (TALP), mWT: Metaplastic Warthin tumor.