The 62-Year-Old with a Painless Neck Lump and a Normal Needle
A 62-year-old man is referred with a 2.5 cm firm, non-tender left level II neck lump found incidentally while shaving. He has a 40 pack-year smoking history and drinks 20 units/week. He has no hoarseness, dysphagia, or weight loss. Flexible nasendoscopy by the referring GP is reported as normal. Fine-needle aspiration of the lump is reported as 'blood only, no diagnostic cells' - a non-diagnostic sample. He is otherwise fit, with no comorbidities, and is keen to avoid 'unnecessary tests'.
1. How should the non-diagnostic FNA and the 'normal' nasendoscopy influence your next step? Justify your reasoning.
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Neither result excludes malignancy, and both must be treated as uninformative rather than reassuring.
Non-diagnostic FNA: A 'blood only' aspirate has a false-negative/non-diagnostic rate that is clinically meaningful, particularly for cystic or necrotic metastases. A non-diagnostic result in a high-risk neck lump is an indication to repeat sampling with ultrasound guidance and/or proceed to core biopsy or excision, not to observe.
'Normal' nasendoscopy: A single examination by a non-specialist does not exclude a small mucosal primary (e.g. base of tongue, tonsillar fossa, pyriform sinus). Examination under anaesthesia with biopsy, plus cross-sectional imaging, is the appropriate next step if no primary is found.
Risk profile: Age >40, significant smoking and alcohol history, and a firm level II node make a metastatic squamous cell carcinoma the leading diagnosis until disproven. The absence of symptoms (no hoarseness/dysphagia) does not lower the pre-test probability meaningfully, because many head and neck primaries are silent at this stage.
Conclusion: Repeat ultrasound-guided sampling with cytology, and if still non-diagnostic, proceed to excision biopsy of the node (with prior discussion at MDT) plus panendoscopy. Observation would be inappropriate.
2. If the repeat sample confirms squamous cell carcinoma in the node but no primary is identified on examination under anaesthesia and imaging, what is the management principle?
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This is a carcinoma of unknown primary presenting as a neck node.
Principles:
- Confirm histology and HPV/p16 status where possible (p16 positivity strongly suggests an occult oropharyngeal primary and alters prognosis and treatment).
- PET-CT is the key investigation to localise an occult primary; if negative, consider bilateral tonsillectomy and base-of-tongue mucosectomy (site-directed biopsies), which identify a primary in a substantial proportion of cases.
- If no primary is found, treat the neck (and at-risk mucosal sites) with definitive radiotherapy or surgery depending on nodal stage and MDT preference.
- Do not simply observe: untreated nodal metastasis carries a poor prognosis.
The judgement tested is that 'no primary found' is a management pathway, not a diagnosis of exclusion requiring no action.