Palatine tonsil squamous cell carcinoma

Non-contrast images showing a left palatine tonsil mass and an enlarged left mandibular lymph node. Further investigation with MRI was advised. 

There is a T1 isointense, T2 mildly hyperintense enhancing large left palatine tonsil mass. It measures approximately 30 mm transverse x 32 mm AP x 28 mm craniocaudal. The lesion infiltrates the anterior and posterior pillars with posterior extension to the posterior oropharyngeal wall. At this level, the tumor abuts the anterior surface of the nasopharyngeal ICA. There is an enlarged 10 mm enhancing left lateral pharyngeal pathological lymph node. The lesion invades the left parapharyngeal fat and infiltrates the medial pterygoid muscle. There is also infiltration of the stylopharyngeus and styloglossus muscles. Anteriorly the lesion extends into the glossotonsillar sulcus without infiltration of the tongue substance.

Superiorly, there is mass-effect on the inferior surface of the torus tubarius with partial fluid effusion in the left mastoid air cell system. There is infiltration of the inferior aspect of the left pterygoid process of the sphenoid bone and involvement of the left side of the soft palate. Posteriorly the lesion extends into the left retropharyngeal fat but there is no infiltration in the longus colli muscle.

There are enlarged pathological left level II A/B lymph nodes with an extracapsular spread in the apex of the left posterior triangle. There is a large left submandibular pathological lymph node along the inferior cortex of the left mandible. A periosteal involvement is not excluded. There is no bone marrow infiltration.

There is no thickening or enhancement along the left mandibular or the maxillary divisions of the left trigeminal nerve. There is T2 hyperintensity and enhancement in the left vidian nerve. There is no bony infiltration of the pterygoid process at the level of the canal. The appearance of the nerve is indeterminate.

Conclusions:

1) There is a large left palatine tonsil squamous cell carcinoma. The suggested radiological staging is T4a (medial pterygoid muscle infiltration) N2b. There is left lateral retropharyngeal nodal metastasis and infiltration of the inferior aspect of the left pterygoid process.

2) There is a large left submandibular pathological lymph node along the inferior cortex of the left mandible. A periosteal involvement is not excluded. There is no bone marrow infiltration.

3) There is T2 hyperintensity and enhancement in the left vidian nerve. There is no bony infiltration of the pterygoid process at the level of the canal. The appearance of the nerve is indeterminate and perineural spread is not entirely excluded.

PET-CT images showing hypercaptation in both the left tonsil lesion and the left mandibular node.