Suspected malignancy

• The recommendation that investigations for suspected head and neck malignancy should be done in secondary care is extrapolated from guidelines on referral for suspected head and neck cancer from the National Institute for Health and Clinical Excellence. These state that, with the exception of persistent hoarseness, investigations for head and neck cancer in primary care are not recommended as they can delay referral [NICE, 2005a].

Glandular fever

• Monospot test (heterophile antibodies) — heterophile antibodies are present in approximately 90% of people older than 12 years of age who have glandular fever, and can be detected by the Monospot test [Johannsen et al, 2005].
• Blood should be taken in the second or third week of the illness, because false negatives are common if taken earlier. False-negative rates may be 25% in week 1 of the infection, decreasing to approximately 5% in week 3 [Ebell, 2004; Smellie et al, 2007].

Lymphadenopathy of unknown cause

• The recommendation on which investigations to request when infection has been excluded and the cause of the lymphadenopathy is unknown is based on referral guidelines for suspected haematological cancer from the National Institute for Health and Clinical Excellence [NICE, 2005a].

Cervical or supraclavicular lymphadenopathy with chest signs

• The recommendation on referring for chest radiography when the person has unexplained cervical or supraclavicular lymphadenopathy for more than 3 weeks is based on a referral guideline for suspected lung cancer from the National Institute for Health and Clinical Excellence [NICE, 2005a].

Thyroid lumps

• CKS identified conflicting recommendations based on expert opinion in referral guidelines for suspected cancer from the National Institute for Health and Clinical Excellence (NICE) [NICE, 2005a] and guidelines on the management of thyroid cancer from the British Thyroid Association (BTA) [BTA, 2007].
• NICE recommends only requesting thyroid function tests in primary care for people with a thyroid swelling without stridor or features requiring urgent referral.
• However, the BTA has subsequently recommended that, for people with a thyroid lump who do not need to be immediately admitted to hospital, thyroid function tests should be requested by the primary healthcare professional and the results included with the referral letter.
• CKS acknowledges that it may be beneficial to do thyroid function tests in primary care, because the results can guide to whom to make a referral and may be useful to the specialist. However, rapid access to secondary care is important when cancer is suspected, and requesting tests should not delay referral.
• NICE and the BTA do not recommend requesting other investigations (such as ultrasonography or isotope scanning) in primary care. This is on the basis of findings from non-randomized clinical trials and expert opinion that this is likely to cause unnecessarily delay in diagnosing cancer [NICE, 2005a; BTA, 2007].