Neck lymph nodes can be the result of tonsillitis, pharyngitis (infection of upper throat), infection in mouth, caries in tooth, internal ear infection, outer ear infection, eczema, dermatitis, dandruff, breast cancer
, fungal infection, other cancers like lymphoma
etc. Since you do not have any other symptoms, and since you do not have a lump in your breast (in males it almost always is taken as cancer), chances of cancer are less. Hence other possibilities should be considered.