Hi Blairs,
Welcome to our special and wonderful group!
To answer your question: YES, schwannomas anywhere on the body and ANs can be related. There are 4 genetic mechanisms possible here: NF-1, NF-2, schwannomatosis and somatic-mosaic. The word "genetic" here means "genetically controlled" which in turn could be either inherited from one or both of your parents or a spontaneous genetic mutation.
NF-1 is characterized by presence of subcutaneous scwannomas (like the ones you had), increased chance of some other conditions and relatively few unilateral AN's.
NF-2 is characterized by bilateral ANs (appearing either simultaneously or within a few year of each other), other CNS scwannomas and cancers and relatively few subcutaneous tumors.
Somatic-mosaic means that the person does not have a fully blown condition and genetic defect is undetectable in the blood but it is present in some cells in the body. It is impossible to predict which ones and there is still an increased chance of tumor formation. Generally (but not always) somatic-mosaics have fewer problems than the ones with a full blown disorder.
Schwannomatosis is a poorly understood disorder where there are subcutaneous schwannomas that usually present with pain that can be significant. Patients are unlikely to develop CNS involvement but because of constant pain, there is a lot of morbidity.
All of these conditions are genetically separate and that means that it is possible theoretically to have more than one. In reality, those who do indeed have more than one are very, very rare. I am not going to go into genes and chromosomes here in order to avoid making this post extra long. You can just google each one, there is plenty of information.
I would strongly recommend going to a local Neurofibromatosis (NF) clinic that exists at most big hospitals. They know all about schwannomas and you will not encounter lack of knowledge or indifference. They can suggest genetic tests to see if you have anything as well as put you on a surveillance schedule. It is true that nobody can predict if you will form a tumor or how fast it will grow but if you learned anything at this forum, it is that with small tumors one has a choice of treatments and doctors, better outcomes and faster recoveries. None of it is present with huge tumors. Progress in AN removal has been made primarily because the tumors are discovered at a much earlier and smaller stage.
Finally, I would like to mention that your age and gender are of paramount importance. Generally, the tumors form faster and grow more in young women of childbearing age. Tumors grow slower in men over 55.
Best of luck to you and keep us posted!
Eve