PET/CT-guided bone biopsies are a promising alternative to conventional techniques to make metabolically active bone lesions-especially without a distinctive morphological correlate-accessible for histological verification. PET/CT-guided biopsies had a major clinical impact in patients who otherwise cannot be reliably stage grouped at the time of treatment decisions.

Objectives/Hypothesis To assess the ability of specific positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) features to detect extracapsular extension (ECE) in head and neck squamous cell carcinoma (HNSCC) patients. Study Design Retrospective study in a tertiary certified university cancer institute. Methods We performed a review of patients with advanced HNSCC at Bern University Hospital between 2014 and 2018. Patients with pretherapeutic PET/CT and/or MRI who underwent neck dissection were included, with 212 patients fulfilling inclusion criteria. Blinded evaluation of specific PET/CT and MRI features with respect to presence of ECE was performed. Histopathological examination of neck dissection specimens was used as the gold standard to determine ECE status. Results Out of the 212 included patients, 184 had PET/CT, 186 MRI, and 158 both modalities. Overall clinical stage IV (odds ratio [OR]: 2.26, 95% confidence interval [CI]: 2.25‐11.74), ill‐defined margins in both PET/CT and MRI (OR: 3.48, 95% CI: 1.21‐9.98 and OR: 2.14, 95% CI: 0.94‐4.89, respectively), and a maximum standardized uptake value ≥ 10 (OR: 5.44, 95% CI: 1.21‐9.98) were all significant independent predictors of ECE. When combined, these four features led to a cumulative score able to predict ECE status with an accuracy of 91.43%. Conclusions The current findings indicate specific features in PET/CT and MRI are potential predictors of ECE status and may help in pretherapeutic stratification in HNSCC. Level of Evidence 4 Laryngoscope, 131:E163–E169, 2021

A 69-year-old man presented with bulging of the right oropharyngeal wall, which revealed cytopathologically malignant cells. The man underwent MRI and F-FDG PET/CT, which demonstrated a cystic parapharyngeal lesion with an F-FDG-avid soft tissue component and right cervical lymph node. The patient was operated on and showed thyroid cancer in normal thyroid tissue, compatible with a papillary thyroid carcinoma in a lateral thyroglossal duct cyst and 2 ipsilateral lymph node metastases. Despite its rarity, papillary thyroid carcinoma in a thyroglossal duct cyst should be kept as one of the differential diagnoses in patients presenting with parapharyngeal cystic lesion.