I have a lump behind me knee and doctor says its a cyst.it is painful and at times can feel a burning sensation.can it be dvt.

Unlikely: Although it is possible to be a dvt, the us would tell for sure. It is most likely a popliteal cyst commonly called a bakers cyst. They do sometimes cause symptoms like you describe. An orthopedist can treat this for you.

Possible: More likely feeling a baker's cyst. Means it is large- goes with some arthritis or prior trauma. Dvt has swelling distal and not usually any palpable in popliteal space. Doppler would show the DVT and can demonstrate a cyst as well. They can both happen together!

Baker's cyst.: Cysts behind the knee are common and they are called Baker's cysts. A venous duplex ultrasound will prove the diagnosis and also evaluate you for DVT.