 The addition of weight loss , appetite loss , vomiting , polyuria , and polydipsia to the aforementioned symptoms may indicate that OFC is the result of parathyroid carcinoma . Parathyroid carcinoma , an uncommon cancer of the parathyroid glands , is generally indicated by serum calcium levels higher than usual , even in comparison to the high serum calcium levels that OFC generally presents with . Symptoms are also often more severe . Generally , the presence of a palpable neck mass is also indicative of the cancer , occurring in approximately 50 % of sufferers , but virtually nonexistent in individuals with OFC with a different origin . 
