most primary head and neck cancers are mucosal lesions , and their mucosal extent can be far better evaluated by the clinician than with ct or mri . indeed , imaging plays little role in the initial detection and characterisation of head and neck malignancies . however , these tumours do have the tendency to spread submucosally , and this extension into the deeply lying tissue planes is sometimes impossible to detect by clinical examination . metastatic adenopathies can be identified , sometimes still in a subclinical stage or at places not accessible by clinical examination , such as in the retropharyngeal or paratracheal lymph nodes . all these findings can profoundly influence the staging and management of the patient with head and neck cancer . finally , imaging may be used to monitor tumour response and to try to detect recurrent or persistent disease before it becomes clinically evident , possibly with a better chance for successful salvage . clinically , these lesions may remain asymptomatic for a long period ; at presentation , the disease is often advanced . the characteristic symptoms are sore throat , referred otalgia and dysphagia , but frequently a neck lump ( due to metastatic neck adenopathies ) is the presenting symptom . the t - staging is determined by tumour size , tumour extent and the presence of hemilaryngeal fixation . early piriform sinus tumours may be very subtle ; images obtained during a modified valsalva manoeuvre ( while letting the patient blow against closed lips ) may be helpful . larger cancers appear as soft - tissue masses , often involving the anterior , lateral and posterior walls of the piriform sinus . soft - tissue thickening or obliteration of the deep fat planes behind the level of the true vocal cord signifies involvement of the piriform sinus apex . inferior extension into the postcricoid area may occur submucosally and , therefore , is endoscopically undetectable . lateral extension may result in extrapharyngeal spread into the neck ; the large neck vessels are then at risk of becoming involved by the primary tumour . cancer of the posterior hypopharyngeal wall commonly appears as a flat but often widespread mass lesion , which may extend into the lower oropharynx . cancer originating in the postcricoid area is rare . besides superior spread within the hypopharynx and extrapharyngeal spread , also involvement of the cervical oesophagus may be seen . these cancers may invade the prevertebral muscles ; ct and mri have a high true - negative but also high false - positive rate in diagnosing such posterior tumour spread . at least 60% of patients with hypopharyngeal cancer present with clinically positive nodal metastases . in a small minority of patients , the primary cancer may at that stage be clinically occult , and may be detected by imaging . at least 75% will have neck adenopathies at some time during the course of disease . apart from clinical examination , minimal screening for distant metastasis at first presentation should include chest x - ray . ct of the chest is the next step when a suspect abnormality is seen on the plain film . chest ct seems justified in advanced stages of the primary tumour and/or bulky neck disease . in borderline - resectable disease , fdg - pet scan may be considered to exclude occult distant disease . postcricoid cancer is treated by total laryngopharyngectomy and reconstruction , usually with a pectoralis major myocutaneous flap . if the tumour extends to the oesophagus , an oesophagectomy is also required . in cancer confined to the piriform sinus or with minimal extension beyond it , if the apex is involved , the risk of laryngeal invasion is high and a total laryngopharyngectomy has to be performed . low - volume hypopharyngeal cancer can be effectively treated by radiation therapy . as in laryngeal cancer , ct ( or mri ) is helpful in assigning patients to a favourable group for radiation treatment , by providing an estimate of tumour volume . it appears that patients with bulky disease at the piriform apex on imaging have a less favourable local outcome after radiotherapy . cancer of the cervical portion of the oesophagus is relatively rare , comprising 35% of all oesophageal cancer . as the lumen of the cervical oesophagus is smaller , these symptoms usually occur earlier than in hypopharyngeal cancer . oesophagography is used to further define the position and extension of the cancer and degree of obstruction . ct / mri are useful to further define the intra- and extraluminal extent of the lesion . the primary drainage nodes of the cervical oesophagus are the paratracheal nodes . as the general lymphatic flow in the upper oesophagus the incidence of nodal metastasis depends on the length of the primary lesion ; lesions more than 5 cm long show adenopathies in 90% of cases . distant metastasis is frequently present at presentation , most commonly to the lungs / mediastinum ( in about 30% of patients ) and liver ( about 15% ) . the high incidence of nodal and distant metastases in patients with cervical oesophageal cancer warrants an extensive pre - operative imaging work - up , including fdg - pet if available . in more than 75% of cases , when technically feasible , the cancer is surgically treated ( oesophagectomy ) , including pharyngolaryngectomy when no safe margin with the upper oesophageal sphincter can be obtained . response to chemoradiotherapy as assessed by serial fdg - pet is strongly correlated with pathological response and survival ; such a correlation was not found for ct and endoscopic ultrasound . overall , the 5-year survival of cervical oesophageal cancer is low ( between 10 and 20% ) . hypopharyngeal and cervical oesophageal cancer are nearly always squamous cell carcinomas .   at presentation , hypopharyngeal cancer commonly presents with neck nodal disease , and the primary tumour may be clinically occult . subclinical submucosal cancer spread is common in both locations , and may be detected by ct / mri . fdg - pet is a useful technique to stage cervical oesophageal cancer , and to assess response to chemoradiotherapy . hypopharyngeal and cervical oesophageal cancer are nearly always squamous cell carcinomas .    at presentation , hypopharyngeal cancer commonly presents with neck nodal disease , and the primary tumour may be clinically occult . subclinical submucosal cancer spread is common in both locations , and may be detected by ct / mri . fdg - pet is a useful technique to stage cervical oesophageal cancer , and to assess response to chemoradiotherapy .