a large intermediate signal intensity mass lesion on T2 w images measuring 4 x4.5 x5 cm is seen in  relation  to the  anterior  two third of the tongue. The mass is seen displacing genioglossus muscle laterally, anteriorly it is seen in relation to the myelohyoid muscles. On either side mass is seen causing obstruction of the submandicular duct. Caudally mass is seen extending into the lingual buccal space. The mass shows heterogenous enhancement after administration of iv contrast. The capsule of the mass is hypointense .

Age- 30-60 years, commonly >40 years

Gender – Male : Female = 1:2

Distribution – 85% in parotid glands, 8% in sub mandibular glands, 0.5% in sub lingual glands, 6.5% from minor salivary glands of oral mucosa or pharyngeal mucosal space

Pathology: originates from myoepithelial cells. Complex, morphologically diverse cellular population – epithelial, myoepithelial and stromal cells.

Natural history: slow growing, benign, painless tumour. Excellent prognosis if no spillage occurs during surgery. Recurrent tumour tends to be multifocal.

2 – 10% of tumours undergo malignant transformation. ‘Carcinoma ex pleomorphic adenoma’ is the most common malignancy. Other types –  carcinosarcoma, metastasizing benign mixed tumour.

Imaging:
MRI – well-circumscribed, lobulated.

T1WI: hypointense to isointense to surrounding muscle.

T2WI: intermediate to hyperintense

Post contrast enhancement is seen.

CT - isodense with heterogenous contrast enhancement. Due to inflammation, margins may not defined. This may give a more aggressive appearance to this benign tumour.

Radionucleide scintigraphy - cold. Helps to distinguish from Warthin's tumour (which in any case is not common at this site).

Angiography: hypovascular.

squamous cell carcinoma (poorly marginated with multiple lymph nodes with central necrosis), lymphoma (associated with multiple enlarged non - necrotic lymph nodes).