A lump on the right side below the rib cage is a possible sign of adult primary liver cancer, according to WebMD. A swelling of the liver causes the lump and other symptoms.
WebMD explains that in adult primary liver cancer, malignant cancer cells grow in the liver’s tissues. It occurs both in children and adults, although treatment for children differs from that for adults. The signs and symptoms of adult primary liver cancer include a hard lump on the right side just beneath the rib cage, pain around the right shoulder blade, discomfort in the upper abdomen, yellowing of the skin and whites of the eyes, unexplained weight loss, nausea and unusual tiredness. It is important to consult a doctor immediately if any of these symptoms occur.
Having cirrhosis or hepatitis increases the risk of developing adult primary liver cancer, notes WebMD. Other possible risk factors include having hepatitis B or C, having a close relative with both liver cancer and hepatitis B, obesity and eating foods contaminated with aflatoxin, which is a poison from a fungus that grows on improperly stored foods. To detect and diagnose this cancer, doctors typically use a physical exam and history, serum tumor marker test, liver function test, CT scan and MRI among other tests and procedures.