A false aneurysm

We report a case of a remaining hemi-thyroid following laryngectomy, which was misinterpreted as a pseudoaneurysm.

Case report and comment on this understandable error which is easily avoidable.

A 59-year-old man had undergone salvage laryngectomy for recurrent squamous cell carcinoma of the larynx, which had previously been treated with radiotherapy. Three months after his laryngectomy, he presented with a sore neck and subcutaneous collections. Computed tomography revealed a unilateral mass with high signal contrast uptake anterior to the left common carotid artery, which was thought initially to be a carotid pseudoaneurysm. Further investigation, including ultrasonography and a review by the senior head and neck radiologist, demonstrated that this mass was actually the remnant hemi-thyroid preserved at laryngectomy (which is often misshapen compared with a normal hemi-thyroid). The collections were found to be recurrent tumour, and unnecessary further interventions were avoided.

Ultrasonography easily distinguishes between a thyroid remnant and a pseudoaneurysm. Furthermore, the opinion of an experienced head and neck radiologist may be vital when interpreting complex post-surgical head and neck radiology.