Hi there
There are a few possibilities as to what these growths could be- as these growths sound as if they are connected to the skin more than anything, then the possibility is that they may be some form of skin tumor- now, this doesn't necessarily mean cancer- so don't panic!! Many types of skin tumor are completely benign and will only grow locally- BUT- the only way to tell this for sure is with some form of histology- this means either a biopsy or a sample of cells needs to be taken from the lump(s) and examined under the microscope.
The other option is that they are cysts. In which case a needle sample will withdraw liquid from the lumps and that will confirm a cystic nature- which is nothing to worry about.
My advise would be to book an appointment at your vets and get an FNA (fine needle aspirate) this involves a needle sample from the lump, is is fairly non invasive and doesn't require an anesthetic- it will provide you with the information you need to know whether or not these lumps need surgical excision.
Regards Andrea
Dog Veterinarian
bvm&s degree, 15 years in companion animal practise