What does having mild bilateral prominence of posterolateral and suboccipital neck nodes mean?

Usually transient: Small nodes are usually reactive to some infection usually upper respiratory, sore throat, etc. and usually resolve in time and are usually not worrisome for malignancy. If nodes persist for long time or increase significantly in size should consult your physician.

Nodes: Probably nothing. Its common to have nodes in that area as a reaction to many things including muscle strain after the gym, hair shampoo and hair coloring. Generally we do an ultrasound to check them out and may repeat it.