Trotter's syndrome

Trotter's syndrome is a cluster of symptoms produced by advanced nasopharyngeal carcinoma that has spread along the mandibular division of the trigeminal nerve through the foramen ovale, and it is characterised by unilateral conductive hearing loss, trigeminal neuralgia and palatal immobility

The syndrome is not a separate tumour but a clinical presentation that signals skull-base and perineural involvement, and its recognition should prompt urgent nasopharyngoscopy and imaging rather than treatment of the pain or the ear as an isolated problem

Because nasal endoscopy can miss submucosal tumour and because perineural spread may occur through radiologically normal-looking tissue, Trotter's syndrome remains a diagnosis in which clinical suspicion and magnetic resonance imaging of the skull base are complementary

Terminology and classification

• Trotter's syndrome is also called Trotter syndrome or Trotter's triad, and the original description linked nasopharyngeal carcinoma with trigeminal neuralgia and conductive deafness
• The classic components are unilateral conductive hearing loss from Eustachian tube obstruction, trigeminal neuralgia from perineural tumour spread and palatal immobility from involvement of the tensor veli palatini or its nerve supply
• Trismus from pterygoid muscle involvement, facial numbness from maxillary or mandibular nerve involvement and multiple cranial neuropathies are frequently added in modern descriptions of the syndrome
• It is classified as a clinical syndrome of nasopharyngeal carcinoma rather than as a histological subtype, and the underlying tumour is usually a non-keratinizing carcinoma associated with Epstein-Barr virus in endemic populations
• ICD-10 coding uses C11.9 for nasopharyngeal cancer and G50.0 for trigeminal neuralgia, and no single code captures the combination, so registries usually record the tumour code as the primary diagnosis
• The principal named differentials are primary trigeminal neuralgia, temporomandibular joint disorder, parotid malignancy, skull-base meningioma, multiple sclerosis, dental infection, adult-onset unilateral otitis media with effusion and juvenile nasopharyngeal angiofibroma

History

• Wilfred Trotter, a British surgeon and thinker who lived from 1872 to 1939, described in 1911 the association of nasopharyngeal tumour with trigeminal neuralgia, and the eponym Trotter's syndrome has been attached to the presentation ever since
• The trigeminal pathway was later explained by perineural spread along the mandibular nerve through the foramen ovale, a route that allows tumour to reach Meckel's cave and the cavernous sinus
• Van Hassel and Topping reviewed the syndrome in 1977 and established the triad of deafness, trigeminal neuralgia and palatal palsy as its core clinical description
• Epstein-Barr virus was identified in 1964, and its causal role in undifferentiated nasopharyngeal carcinoma was established in the 1970s, and serological and later molecular testing became part of diagnosis in endemic regions
• Intensity-modulated radiotherapy, introduced in the 1990s and 2000s, improved tumour coverage while sparing the parotid glands, brainstem and optic structures, and became the standard technique for nasopharyngeal carcinoma
• A 2006 case report described nasopharyngeal carcinoma mimicking a temporomandibular disorder, illustrating why Trotter's syndrome is still misdiagnosed when the trigeminal pain is attributed to dental or joint disease

Epidemiology

• Nasopharyngeal carcinoma is endemic in southern China and Southeast Asia, and GLOBOCAN 2020 together with regional registries places incidence at around 20 to 30 per 100,000 person-years in high-risk regions, compared with fewer than 1 per 100,000 in most European and North American populations
• Intermediate incidence is seen in North Africa, the Arctic and parts of the Middle East, and migration studies show that incidence falls in subsequent generations after migration to low-risk countries
• Men are affected about two to three times more often than women, and the peak age is between 40 and 60 years in endemic areas, with a secondary peak in adolescence and young adulthood in some populations
• Trotter's syndrome represents advanced disease with skull-base or perineural involvement, and its exact proportion among nasopharyngeal carcinoma cases is not known because series use different diagnostic thresholds and imaging protocols
• Because nasopharyngeal carcinoma is far more common in endemic regions, Trotter's syndrome is encountered disproportionately there, and clinicians in low-incidence countries may see it only as an imported or immigrant diagnosis
• Established risk factors include Epstein-Barr virus infection, consumption of salted fish and other preserved foods, tobacco smoking, heavy alcohol use and occupational exposure to formaldehyde or wood dust
• Family history and certain HLA haplotypes increase risk, and genetic susceptibility interacts with dietary and viral exposures in endemic populations
• Survival is strongly stage-dependent, with five-year overall survival above 90% for stage I disease and roughly 50% to 70% for stage IV disease treated with modern radiotherapy and chemotherapy

Pathophysiology

• Nasopharyngeal carcinoma usually arises in the fossa of Rosenmüller and grows submucosally, which is why a normal-looking nasopharynx does not exclude tumour and why deep biopsies are sometimes required
• Perineural spread follows the mandibular nerve from the parapharyngeal space through the foramen ovale into Meckel's cave, and tumour can extend retrogradely toward the cavernous sinus and brainstem
• Perineural spread can be discontinuous, so imaging may show enhancement or nerve thickening far from the primary tumour and may underestimate the true extent of microscopic disease
• Eustachian tube obstruction by tumour or by radiation-induced oedema produces middle-ear effusion and conductive hearing loss, which is often the first symptom and is frequently treated as simple otitis media
• Involvement of the tensor veli palatini, levator veli palatini or the pterygoid muscles produces palatal immobility, nasal regurgitation, dysarthria and trismus, and these features indicate disease beyond the mucosal surface
• Epstein-Barr virus latent proteins such as LMP1 and LMP2 activate NF-kappa-B and other survival pathways, and the combination of viral, genetic and dietary factors produces the characteristic undifferentiated carcinoma of endemic populations

Clinical features

• Unilateral conductive hearing loss, tinnitus and aural fullness are common presenting symptoms, and otoscopy may show a dull tympanic membrane or middle-ear effusion in an adult without the usual predisposing illness
• Trigeminal neuralgia in the mandibular distribution produces lancinating jaw pain, toothache-like discomfort and facial numbness, and dental treatment may be attempted before the tumour is suspected
• Palatal immobility causes nasal regurgitation of fluids, hypernasal speech and difficulty pronouncing palatal consonants, and examination may show the soft palate failing to elevate on phonation
• Trismus, deep facial pain and pterygoid tenderness indicate involvement of the masticator space, and they are poor prognostic signs because they reflect advanced local disease
• A painless upper neck mass is present in many patients and may precede nasal symptoms, while epistaxis, nasal obstruction and cranial nerve palsies appear as the tumour enlarges
• Red flags for Trotter's syndrome include unilateral middle-ear effusion in an adult, persistent unilateral headache or facial pain, progressive facial numbness, diplopia and any cranial neuropathy without an obvious cause

Diagnosis

• Nasopharyngoscopy with biopsy of the fossa of Rosenmüller or any suspicious submucosal bulge is the diagnostic procedure of choice, and multiple deep biopsies may be needed when the surface appears intact
• Contrast-enhanced magnetic resonance imaging of the nasopharynx and skull base is essential for detecting perineural spread along the trigeminal nerve and for distinguishing tumour from mucosal thickening
• Computed tomography complements magnetic resonance imaging for bone erosion of the skull base and for radiotherapy planning, and the two modalities are usually interpreted together
• Plasma Epstein-Barr virus DNA is a sensitive tumour marker in endemic populations and is used for diagnosis, staging, response assessment and surveillance after treatment, and staging follows the AJCC eighth edition published in 2017
• Audiometry and tympanometry document conductive hearing loss and middle-ear effusion, and cranial nerve examination should map trigeminal, abducens and lower cranial nerve function before treatment
• The differential includes primary trigeminal neuralgia, temporomandibular disorder, parotid or skull-base malignancy, meningioma, multiple sclerosis, dental abscess and simple otitis media with effusion, and biopsy or imaging is required when any red flag is present

Management

• Treatment is planned by a multidisciplinary head and neck tumour board in line with the NCCN and CSCO head and neck guidelines and is based on stage, Epstein-Barr virus DNA, performance status and the presence of skull-base or perineural involvement
• Intensity-modulated radiotherapy with concurrent cisplatin is the standard curative approach for locally advanced nasopharyngeal carcinoma, and it offers better sparing of salivary glands, hearing structures and brainstem than older techniques
• Induction chemotherapy with a platinum, taxane and fluoropyrimidine combination, or with gemcitabine and cisplatin, is used for bulky or high-risk disease before radiotherapy
• Adjuvant chemotherapy after concurrent chemoradiotherapy is used in selected high-risk patients, and the choice between induction and adjuvant strategies depends on local protocols and toxicity considerations
• Immune checkpoint inhibitors such as pembrolizumab or nivolumab are used for recurrent or metastatic disease, and their role in the adjuvant setting is being tested in clinical trials
• Surgery has a limited role in primary treatment but is used for selected recurrent disease, for residual neck nodes and for biopsy or palliation of complications
• Supportive care includes hearing aids or tympanostomy for effusion, palatal prosthesis or speech therapy for velopharyngeal insufficiency, physiotherapy for trismus and neuropathic analgesics such as carbamazepine or gabapentin for trigeminal pain
• Surveillance after treatment combines nasopharyngoscopy, magnetic resonance imaging and plasma Epstein-Barr virus DNA, and it should also monitor hearing, swallowing, dental health, xerostomia and radiation-induced hypothyroidism

Research and controversies

• How best to treat perineural spread along the trigeminal nerve is unresolved, because the tumour may be microscopic beyond the visible enhancement and because the risks of skull-base surgery must be balanced against the benefits of local control
• Whether induction chemotherapy adds survival benefit to concurrent chemoradiotherapy in all stage III to IVA patients or only in high-risk subgroups is still debated, and trial results have differed across endemic and non-endemic populations
• Epstein-Barr virus DNA screening in endemic areas can detect early asymptomatic cancer, but cost, false positives and optimal screening intervals remain unresolved, and the approach has not been adopted uniformly
• Proton therapy may reduce radiation dose to the temporal lobes, brainstem and cochlea, but evidence that it improves outcomes over intensity-modulated radiotherapy is limited and access is restricted
• Late effects of treatment, including sensorineural hearing loss, xerostomia, trismus, dysphagia and second cancers, are increasingly important as survival improves, and survivorship research is needed to guide rehabilitation and surveillance