Hi and thanks for the query, A clinical examination is actually required. Its a possibility bu other parameters need to be taken into consideration first. It could be interesting for you to get a chext X ray done first to ascertain the integrity of the chest wall and contents. A mass as such could be associated with a local or loco regional infectious process too. A complete blood count, measurement of markers of inflammation and a complete physical examination could be a good orientation on the causes of symptoms. Polyuria required a urine analysis to be done and a fasting blood sugar at least to rule of a possibility of diabetes mellitus and a urinary infection first. I suggest you consult your primary care physician, thanks and best regards, Luchuo, MD.