predisposing and precipitating factors
the previous history of burn has been noted in one case of PBOS (6) but to the best of our knowledge, it has not been reported elsewhere. Prior history of epithelial breast cancer in the same side or contralateral side has been reported several times (7,8). Some reported cases develop PBOS after irradiation (9, 10). In addition, some cases presented with a history of trauma or even a foreign body (2).