The dangers of diagnosing cystic neck masses as benign in the era of HPV-associated oropharyngeal cancer
A 59-year-old woman presented to her general practitioner with a lump in the left neck. She was a non-smoker, non-daily drinker and had no significant past medical history. Fine needle aspiration biopsy (FNAB) was performed and led to the diagnosis of a branchial cleft cyst. The mass collapsed after aspiration and the patient was managed conservatively by observation. In the year after diagnosis, re-emergence of the mass was noted by the GP at follow-up. Further investigations were declined on the patient’s presumption that the lesion was a benign branchial cleft cyst.
Two years after her initial diagnosis, the patient re-presented with a 1- to 2-month history of a sore throat and further increase in the size of the neck mass. On examination, a 7 cm mass was palpable, there was no overlying skin invasion and the mass was mobile to deep structures. Repeat FNAB of the neck mass was performed and revealed squamous cell carcinoma (SCC) with p16 positivity.
A staging computed tomography (CT) scan detected a lobulated tumour centred on the left tonsil invading the vallecula, base of tongue and parapharyngeal space. Further, a 27 mm cystic mass consistent with her initial lump was identified in the left level II group of lymph nodes, with additional necrotic nodes present at levels III and IV. A subsequent positron emission tomography scan confirmed increased…