Patients suspected to have lymphoma, based on the clinical assessment during the initial general practitioner visit, should be immediately referred to a specialist for diagnosis.

For patients where there is a lower index of suspicion, further examinations/investigations by the general practitioner should include (but are not limited to):

• a thorough history and physical examination of the skin, all lymph node groups, oral examination for enlarged Waldeyer’s ring, abdominal examination and cardiorespiratory examination
• blood tests to assess organ dysfunction including: full blood count, urea, electrolytes, creatinine, liver function tests, lactate dehydrogenase (LDH); other tests may include beta-2 microglobulin (no laboratory test can exclude these lymphomas)
• imaging of the affected area including ultrasound, chest radiography and computed tomography (CT) scan as appropriate
• biopsy as appropriate, depending on local access (referral to a specialist prior to biopsy may be appropriate where there is a high clinical suspicion for lymphoma)
• fine-needle aspiration (FNA) is generally considered inadequate for diagnosing low-grade lymphomas but in some instances may be an appropriate initial investigation (e.g. in evaluating an enlarged lymph node when a non-haemopoietic neoplasm is strongly suspected (such as head and neck cancer).

Indicators of concern that should lead to prompt referral to a specialist include:

• symptoms or results indicating organ dysfunction and low blood counts
• symptoms that suggest neurological involvement
• markedly elevated LDH
• marked B symptoms (weight loss > 10 per cent, persistent fevers > 38°C, or persistent drenching night sweats).