What is the most likely diagnosis for a hard mass found midline in the palate, with no other symptoms?

A hard mass located midline in the palate, especially in the absence of other symptoms, is most consistent with torus palatinus. This is a bony growth that typically appears as a midline prominence on the hard palate and is often asymptomatic, meaning it does not cause pain or discomfort to the individual. It is considered a normal anatomical variant and is relatively common, particularly in adults.

The presentation fits torus palatinus because it is usually a well-defined, hard mass and is not associated with any inflammatory or infectious processes that might suggest another condition. Other growths or cysts in the palate could potentially present with different characteristics or symptoms, such as swelling or discomfort, making them less likely diagnoses in this case.