Reflex sympathetic dystrophy syndrome (RSDS) is a rare entity of unknown etiopathogenesis, associated to different precipitating factors such as malignant tumors of several localizations. A new clinical variety has been recently described which has been denominated palmar fasciitis and polyarthritis syndrome. We present here two patients with RSDS associated to breast cancer: one case presenting fasciitis and polyarthritis and another case also associated to polymyalgia rheumatica. We emphasize the importance of reducing the tumor mass in the treatment of this syndrome, as well as including it in the gammagraphic differential diagnosis of bone metastasis.