Some cases of severe post-mastectomy pain syndrome may be caused by an axillary haematoma.

Post-mastectomy pain syndrome (PMPS) is experienced by 20-65% of patients who undergo breast surgery for cancer. The etiology of this chronic neuropathic pain syndrome is unclear and most likely multi-factorial. Symptoms may be mild, not requiring treatment, or severe, considerably restricting quality of life. The effectiveness of available pharmacological and pain management therapies is unknown. Certainly, some women remain under-treated with poor pain control. We report three women undergoing wide local excision for cancer of the breast and block dissection of axillary lymph nodes who subsequently developed severe PMPS. In these cases the symptoms were completely relieved by the aspiration or formal drainage of an encapsulated haematoma in the axilla. The removal of a minimal amount of blood brought instant improvement suggesting that pressure within the haematoma could be an etiological factor. An axillary haematoma, which may not be clinically obvious, should be considered as a possible cause of PMPS.