When to see a doctor See your doctor if youre concerned or if your swollen lymph nodes: Have appeared for no apparent reason. In the absence of a known disease, an enlarged node must be regarded as likely hyperplastic or reactive. Furthermore, a cancer diagnosis doesnt mean one set path for treatment. pea- or bean-sized lumps under the skin tenderness or soreness when you touch them redness and warmth of the skin over the swollen nodes Other symptoms to watch for If your lymph nodes are. Diagnostic usefulness of fluorine-18--methyltyrosine positron emission tomography in combination with 18F-fluorodeoxyglucose in sarcoidosis patients. //