This is an irregular verb. It follows the conjugation pattern of the verb passear.
Present:
A Sofia massageia o pescoço depois do trabalho.
Sofia massages her neck after work.
Preterite:
O Miguel massageou o ombro ontem.
Miguel massaged his shoulder yesterday.
Conditional:
A Ana massagearia as costas do bebê com cuidado.
A Ana massagearia as costas do bebé com cuidado.
Ana would massage the baby's back gently.