Non-cyclical mastalgia: an improved classification and treatment.

A prospective study of 72 patients with non-cyclical breast pain was carried out. Non-cyclical breast pain was subdivided into true non-cyclical mastalgia (35 patients) and musculoskeletal pain (37 patients), the latter including Tietze's syndrome and other causes of chest wall pain. Mean age at presentation was significantly greater in the musculoskeletal group (39.3 versus 33.9 years) with a shorter mean duration of pain (14.7 versus 35.4 months) compared with the non-cyclical mastalgia group. True non-cyclical mastalgia was commonly bilateral and located within the upper outer quadrant of the breast, whereas musculoskeletal pain was almost always along the lateral chest wall or costochondral junctions and unilateral in 92 per cent of cases. Breast nodularity was present in 54 per cent of patients with non-cyclical mastalgia, but in only four cases (11 per cent) in the musculoskeletal group. Nine of 14 patients (64 per cent) with non-cyclical mastalgia obtained a good clinical response to drug therapy (over half responding to danazol alone); 19 underwent spontaneous remission, but there was a prolonged mean time to pain resolution of 27 months. In the musculoskeletal group 33 of 34 patients (97 per cent) had a good response to steroid and local anaesthetic injection; three resolved spontaneously without treatment, with a mean time to pain resolution of 17 months. This study indicates that differentiation of musculoskeletal pain from non-cyclical mastalgia may lead to more effective treatment with some prediction of the overall prognosis.