Would small cell lung cancer in a mediastinal lymph node be classed as cancer of unknown primary if lung was clear on imaging.

SCLC arises next: to the bronchi and may not be visible on CT imaging in spite of the fact that it has already spread to a lymph node. Very rarely this same type of tumor arises in the prostate, cervix or gastrointestinal tract. Perhaps a sophisticated imaging technique such as PET scanning could detect the primary tumor in the lung, though knowing the type of tumor already can guide their treatment effectively.