Post Mastectomy Pain is a chronic pain that occurs after surgery for breast cancer.  Anywhere from 20-68% of mastectomy patients may experience this painful condition.  It occurs more often when surgery includes the upper and outer quadrants of the breast.  It is also more likely to occur if surgery is done in the axilla, and if the patient undergoes chemotherapy or radiation therapy.  The pain can range from mild to severe and incapacitating.  It is usually caused by damage to nerves in the area of surgery.  The pain can be described as burning, tingling, shooting or stabbing.  It can be located in the area of surgery or radiate around the front or back of the chest wall.  It can interfere with everyday activities and cause sleep disturbances.  Movement of the arm may worsen the pain.  This leads to muscle wasting and weakening of the arm.  Lympedema may develop.  MRI, CT scans and X-rays are used to exclude residual disease as well as other pathological causes of pain such as fractures.  Electromyography and Nerve Conduction Studies are used to delineate the nerves that may be damaged from surgery.  Treatment is conservative and begins with non-steroidal anti-inflammatory medications and narcotics for pain relief.  Tricyclic anti-depressants such as amitryptyline can be used to treat the neuropathic component of pain.  These medications have side effects such as sedation and dry mouth which may be poorly tolerated.  The seratonin and norepinephrine reupatake inhibitors (SNRI) such as Cymbalta are useful for treatment.  Gabapentin (Neurontin) and Pregabalin (Lyrica) are a third class of medication also useful in the treatment of post mastectomy pain. Occasionally, nerve blocks with a local anesthetic and a steroid administered to the injured nerve may reduce pain as well.