When one palpated an abnormal lymph node or nodes on the neck, the differential diagnosis consist of the following:
- Reactive hyperplasia
- Malignant lymphadenopathy, either primary (lymphoma) or secondary (metastatic)
- TB lymphadenopathy
Though not foolproof, the following clinical diagnostic algorithm is helpful from my experience in the Filipino patients. I use a combination of pattern recognition, prevalence and elimination processes.
Reactive hyperplasia is suspected when there are symptoms and signs of an inflammation in the nearby area of the head and neck.
Secondary malignant or metastatic lymphadenopathy is suspected when there is a lesion in the head and neck that looks like cancer which could be the source of the spread to the lymph nodes.
Primary malignant lymphadenopathy, most common is lymphoma, is suspected when there are multiple big (more than one cm) lymph nodes in the neck area (especially if there are also enlarged lymph nodes in axilla and inguinal areas) and reactive hyperplasia and TB lymphadenopathy are unlikely.
TB lymphadenopathy is suspected when reactive hyperplasia and malignant lymphadenopathy are unlikely. TB lymph nodes are usually located in the posterior triangle of the neck.