A Tumor or tumour (via Old French tumour from Latin tumor "swelling") originally meant an abnormal swelling of the flesh. In contemporary English, tumor has evolved to become synonymous with neoplasia, all other forms being called swelling . This tendency has also become common in medical literature. The noun tumefaction, derived from the adjective tumefied, is the current medical term for non-neoplastic tumors . Causes Tumors and/or swellings can be caused by: Neoplasia, an abnormal prolifera… (More on Tumor)