My 15 year old daughter just found a small lump on the right side of her neck just below her ear. Last week she went to the emergency room due to excessive vomiting and dehydration. They ran several tests to rule out Mono and Appendicitis. Those two test came back negative, however, a reading of the CT scan of her ABD (w/out contrast) showed a slightly enlarged spleen. Her WBC was a little over 17,000. She seems fine otherwise. The lump is sore when it is pressed on.