Final answer:
Metastases to oral soft tissues are considered rare but can be significant as they may signal an advanced stage of cancer or an undiagnosed systemic malignancy.
Step-by-step explanation:
The question of how common metastases to oral soft tissues are falls under the category of medicine, particularly oncology. The most accurate answer is that metastases to the oral soft tissues are relatively rare. Cancers that originate in other parts of the body can spread, or metastasize, but when they do, the oral cavity is not among the most common sites for these secondary tumors to develop. Typically, oral metastases might be seen in advanced stages of cancer and could originate from primary cancers of the lung, kidney, breast, and skin among others. Clinicians need to be vigilant since a metastatic lesion in the mouth might be the first sign of an undiagnosed systemic malignancy.