Squishy lump on crown of head.

Our sweet girl is 10 months old. We noticed a this evening that she has formed squishy lump on the top of her head. After researching there is too many variables to pin down what it may be. We found that it may be common in Basset Hounds. I am wondering if anyone has experienced this with their hounds. We have a call into the vet. The after hours on call said it may or may not be of concern and said the office would call back tomorrow to schedule an appointment.