Cancer of the oral cavity and oropharynx

Abstract

Tumours in the oral cavity and oropharynx differ in presentation and prognosis and the detection of spread of tumour from one subsite to another is essential for the T-staging. This article reviews the anatomy and describes the pattern of spread of different cancers arising in the oral cavity and oropharynx; the imaging findings on computerized tomography and magnetic resonance imaging are also described. Brief mention is made on the role of newer imaging modalities such as [(18)F]fluorodeoxyglucose-positron emission tomography/computed tomography, perfusion studies and diffusion-weighted magnetic resonance imaging.

Figure 1

Sagittal T2-weighted MR image (A) in the median plane showing normal anatomy and the division of the oral cavity and oropharynx. Coronal T2-weighted image (B) and sagittal T2-weighted image (C) showing the various structures in the oral cavity. OC, oral cavity; OP, oropharynx; HP, hypopharynx; L, larynx; N, nasopharynx; H, hard palate; S, soft palate; Hy, hyoid bone; E, epiglottis. Muscles of the tongue: SG, styloglossus muscle; GG, genioglossus muscle; GH, geniohyoideus; IM, intrinsic muscles; Lg, superior longitudinal muscles; Tr, transverse lingual muscles. Muscles of the floor of the mouth: MH, myelohyoid muscle; D, anterior belly of the digastric muscle.

Figure 2

Axial MR images in a patient with proven cancer of the left tonsil. The tumour (arrow) is well delineated, hypointense on T1-weighted (A), hyperintense on T2-weighted (B) with enhancement after contrast injection (C).

Figure 3

CT images, coronal reconstruction (A) and axial images (B) showing a histologically proven case of adenoid cystic carcinoma of the hard palate (star) with extension along the greater palatine nerve and replacement of fat (arrow) in the greater palatine foramen. Compare the normal foramen on the right side.

Figure 4

Axial T1-weighted MR images before contrast injection (A,B) showing the hypointense tumour of the hard palate on the left (star) with loss of normal fat signal in the pterygopalatine fossa on the left (arrow) in a patient with proven lymphoma and perineural extension of the tumour. The coronal image after gadolinium injection with fat suppression (C) shows enhancement of the greater palatine nerve on the left (arrows).

Figure 5

Axial T2-weighted MR image of a patient with histologically proven squamous cell cancer of the floor of the mouth showing the tumour with involvement of the mandible and extension into the adjacent soft tissues anteriorly (star). Note obstruction with dilatation of the Wharton duct on both sides (arrows).

Figure 6

Axial T1-weighted MR images before (A) and after contrast administration with fat saturation (B) in a patient with proven cancer of the retromolar trigone on the right (star). Note infiltration of the buccinator muscle and extension along the alveolar ridge (arrow).

Figure 7

Axial T1-weighted MR images before (A) and after contrast injection with fat saturation (B) in a patient with cancer of the tongue on the left side (star). The tumour does not cross the midline which is represented by the fatty signal intensity of the lingual septum (arrow).

Figure 8

Axial CT images in soft tissue (A) and bone window (B) showing the histologically confirmed alveolar SCC (star) and the bony erosion (arrow).

Figure 9

Axial CT image (A) in a patient with proven SCC of the base of the tongue showing the tumour (arrows) with central necrosis and a necrotic lymph node on the right side (star). The tumour extends into the valleculae on both sides and displaces the epiglottis posteriorly. Sagittal reconstruction (B) showing the tumour (star) with infiltration of the preepiglottic space (arrow).

Figure 10

Axial (A) and sagittal (B) T1-weighted MR images after contrast injection with fat saturation showing the enhancing tumour of the posterior pharangeal wall presenting as a submucosal mass crossing the midline.

Figure 11

Axial T2-weighted MR image (A) and axial T1-weighted image (B) after contrast injection with fat suppression showing the large soft palate tumour (star) with enlargement of the retropharyngeal lymph nodes on both sides (arrows) in a patient with cancer of the uvula.