Why would a doctor on this site refer me to an oncologist after i asked why i saw dark spots on my heart during a echo stress test?

Dark spots?: Hopefully you had normal cardiac function on the stress echocardiogram test. Sometimes an echocardiogram will show "dark spots" near the heart. These might be enlarged lymph nodes that should be evaluated by additional studies (CAT scan of the chest) and it is also reasonable to see an oncologist since there is a slight chance the lymph nodes could represent lymphoma.