Thanks for writing to H.C.M. for query.
I have gone through your query regarding pain on swallowing and swelling of palate looking like a lump. You are in doubt that our sinuses are just above the palate , So I would like to clear you that above the palate lies our nasal cavity
and only the alveolar border (teeth shocket ) of palate forms the floor of maxillary sinuses.
The possiblities in your case are-
(1) Palatal cellulitis
(2) Ectopic salivary gland
To confirm yu have to do M.R.I. of paranasal sinuses
and palate which will confirm the diagnosis and that may be treated accordingly.