Are cervical polyps always removed and biopsied during d&c's?

Yes: Nearly always if the physician knows there are polyps there she/he will remove them during a d;c. If doctor knows there is only one polyp, then d;c is sufficient. If there may be multiple polyps then a hysteroscopy, d;c might be preferable. But a polyp can always contain small amount of cancer cells so doctors typically always like to remove them and send to pathology to examine microscopically.