Post-mastectomy pain syndrome (PMPS) is a chronic pain condition, neuropathic in nature, which can occur following surgery of the breast.
Mastectomy is the surgical removal of the breast, usually to remove a malignant tumor. Mastectomy might also be carried out in conditions like cystic breast disease or if a lump is too big to be removed by lumpectomy.
The pain arising out of PMPS is typically characterized as a dull, burning and aching sensation in the anterior chest, arm and axilla and is exacerbated by movement of the shoulder girdle.
Recent studies report that chronic pain has also been reported after other breast procedures including lumpectomy, breast reconstruction, augmentation and reduction.
Research indicates that an estimated 30% to 60% of women develop this chronic neuropathic pain syndrome after lumpectomy or mastectomy. In addition, younger women are reportedly at a greater risk of developing symptoms of the post mastectomy pain syndrome.
Causes of PMPS
Pain in the post mastectomy pain syndrome usually results from irritation of one or more of the nerves in the chest wall, which may be entrapped by scar tissue or cut during the surgery.
In a few cases, a neuroma or a painful bundle of nerves grows at the stump of a nerve that has been cut. Meanwhile, for some patients with post mastectomy pain, the muscles of the chest, shoulder or arm can also contribute to the pain.
The pain syndrome may also develop as a result of surgical trauma to nerves or if acute pain is not treated properly in the first 24 hours after surgery.
Lastly, some researchers believe that certain psychological factors also play a role in the development of symptoms, apart from actual physical injury or stress.
Diagnosing post mastectomy pain syndrome often becomes extremely difficult. This is partly due to the fact that the problem often takes 30 to 60 days to become apparent enough.
Besides, in a very small percentage of patients, pain as well as paresthesia becomes visible immediately after the surgery. Paresthesia is a creeping, tingling sensation, which the patient feels in such pain syndromes.
Neuropathic pain such as that arising from the post mastectomy pain syndrome responds best to a combination of treatments. For instance, two drugs with differing mechanisms of action are at times prescribed for better results.
Medications for PMPS
Common medications prescribed for PMPS include tricyclic antidepressants such as nortriptyline (Pamelor) and amitriptyline (Elavil), which target neurotransmitter activity. Anticonvulsant medications such as gabapentin (Neurontin) and Pregabalin (Lyrica) are also known to provide relief.
For topical application, lidocaine (Lidoderm) patches can be placed directly over the painful area for up to 12 hours. Application of capsaicin cream or cold packs to the painful area is also helpful in some cases.