Chasing the primary

Background:
Metastatic neck disease is typically due to primary squamous cell carcinoma (SCC) originating within the head and neck and the location of the first metastatic cervical lymph node can be an indicator of the potential origin of the primary tumour. The presence of a metastatic disease without an identified primary tumour, termed unknown primary, poses significant diagnostic and therapeutic challenges, with the patient requiring extensive investigation by a multidisciplinary team.

Case:
We present a case of a 66-year-old male patient who presented with erythroleukoplakia in the right buccal mucosa, a mobile infected LR7 and right sided lymphadenopathy. Extraction of the infected LR7 tooth was performed and a biopsy of the buccal mucosa revealed moderate epithelial dysplasia. At his review visit his lymphadenopathy was still present and an urgent ultrasound revealed a suspicious right level 1b lymph node. A fine needle aspiration (FNA) confirmed a SCC. The patient reported no aerodigestive tract or systemic symptoms. He had a background history of hypertension, hypercholesterolaemia and was partially sighted. He had a 20-year pack history, quitting smoking 21 years ago.

A prompt assessment by the Head and Neck team was undertaken which included flexible nasoendoscopy and MRI head & neck, with no index primary identified. A whole-body PET CT revealed avid uptake of Fluorodeoxyglucose F18 (FDG) in the ileocolic lymph node, which following MRI small bowel was deemed to be insignificant. A panendoescopy, tonsillectomy, tongue base mucosectomy and wide local excision of right buccal mucosa was undertaken revealing no signs malignancy. A selective neck dissection was also performed.

Discussion:
We discuss the possible origins of metastatic neck disease and the multidisciplinary team approach to diagnosing unknown primary tumours of the head and neck along with careful surveillance to optimise patient outcomes.