Hello, This is a difficult condition to evaluate without examining the mass. There are certain qualities of a mass that are more indicative of a need to have a physician perform a physical exam and history. These would include new masses (infection, enlarged lymph nodes, and tumors), masses that are becoming larger, masses that are painful to touch and masses that seem to be non-mobile under the skin, new pulsatile masses, etcetera. Redness or increased warmth at a mass site could indicate infection. Trauma causing bruises, hematomas or fractures with associated masses would likely be associated with a known trauma and would appear to have a reddish or bruised appearance, generally. The primary care or ER (Emergency Room) doctor would be able to easily begin the process of deciding what a new mass is caused by. In addition to a history and physical, he/she could order appropriate imaging studies, lab work or arrange for a referral to a specialist. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Matthew Jones