The added value of hybrid positron emission tomography is increasingly recognised in head and neck cancer. However, its potential role in salivary gland carcinomas has been scarcely investigated.

A consecutive cohort of 45 salivary gland carcinoma patients who underwent pre-therapeutic hybrid positron emission tomography and surgical resection was reviewed. This study investigated whether maximum standardised uptake value correlated with tumour phenotype.

Tumours of high-grade disease on histology (salivary duct carcinoma, carcinoma ex pleomorphic adenoma) had higher maximum standardised uptake value (Kruskal–Wallis test, p = 0.011) than low-grade tumours (adenoid cystic carcinoma and acinic cell carcinoma). Patients with pathologically confirmed node-positive disease had significantly higher maximum standardised uptake value of the primary tumour than patients with pathologically confirmed node-negative disease (Kruskal–Wallis test, p = 0.012).

Maximum standardised uptake value of the primary tumour may guide clinical decision-making in patients with salivary gland carcinomas, as a high maximum standardised uptake value is associated with high-grade tumour histology and the presence of lymph node metastases. Clinicians may consider more aggressive surgery for these patients.

Positron emission tomography-computed tomography with fluorine-18 fluorodeoxy-D-glucose has a major role in the investigation of head and neck cancers. Fluorine-18 fluorodeoxy-D-glucose is not a tumour-specific tracer and can also accumulate in benign pathology. Therefore, positron emission tomography-computed tomography scan interpretation difficulties are common in the head and neck, which can produce false-positive results. This study aimed to investigate patients detected as having abnormal vocal fold uptake on fluorine-18 fluorodeoxy-D-glucose positron emission tomography-computed tomography.

Positron emission tomography-computed tomography scans were identified over a 15-month period where reports contained evidence of unilateral vocal fold uptake or vocal fold pathology. Patients’ notes and laryngoscopy results were analysed.

Forty-six patients were identified as having abnormal vocal fold uptake on positron emission tomography-computed tomography. Twenty-three patients underwent positron emission tomography-computed tomography and flexible laryngoscopy: 61 per cent of patients had true-positive positron emission tomography-computed tomography scans and 39 per cent had false-positive scan results.

Most patients referred to ENT for abnormal findings on positron emission tomography-computed tomography scans had true-positive findings. Asymmetrical fluorine-18 fluorodeoxy-D-glucose uptake should raise suspicion of vocal fold pathology, accepting a false-positive rate of approximately 40 per cent.

Renal metastasis is relatively unusual in patients with differentiated thyroid carcinoma.

The clinicoradiological parameters of a series of patients with differentiated thyroid carcinoma and renal metastasis were assessed, together with follow-up data.

The series comprised 4 male patients over the age of 45 years with extensive disease at the primary site. Retro-sternal extension of a large goitre was observed in three patients. The primary tumour was 4 cm or larger in all patients (range, 4–14 cm), and three patients had associated lymph node metastasis. None had any genito-urinary symptoms at presentation. Two patients had isolated renal metastases with no other distant metastases, while the others had extensive multi-organ involvement. The bilateral occurrence of lesions was a hallmark, being observed in all cases. Ultrasound-guided fine needle aspiration cytology and 131I scintigraphy were pivotal in confirming the diagnosis. Evidence of ‘flip-flop’ between 131I study and fluoro-deoxyglucose positron emission tomography was noted in one patient, while the other three demonstrated concordant lesions in both modalities. At a minimum follow-up period of four years after diagnosis, three patients demonstrated stable disease with radioiodine therapy, and one had expired due to a poorly differentiated lung carcinoma which developed subsequently.