Hi and thanks for the query, Abnormal liver function tests under such circumstances need careful considerations. An enlarged or inflammed liver on its own could explain the shoulder pain, neck pain and fatigue. It s mandatory to know the cause of the raised liver enzymes. Hepatitis A, B C and D should be ruled out systematically. An abdominal ultrasound could be useful in getting the know the size of the liver and the spleen. It is very rare that this could be infectious Mononucleosis. In IM, raised white blood cells are seen, enlarged lymph nodes and usually with spleen enlargement and not liver most of the time. It s not usual to have raised liver enzymes in this condition. I strongly suggest you consult your primary care physician and evaluation of your liver function. Kind regards, Bain LE, MD.