What are the signs and symptoms?

Patients with cancer of unknown primary usually notice a lump in their neck, which is usually painless. Most patients don’t have any other symptoms.

Swollen lymph nodes may be due to an infection, such as a cold or flu, but the swelling should subside after two weeks. Children and young adults may sometimes have persistently enlarged lymph nodes due to viruses such as glandular fever.

However, adults that notice a swollen lymph node that does not go away within four weeks should consult their doctor. Adults presenting with enlarged lymph nodes for a month or longer may be recommended a needle biopsy to check for cancer.