Which condition involves a cystic tumor that can develop on tendons?

The condition that involves a cystic tumor that can develop on tendons is indeed a ganglion. Ganglion cysts are non-cancerous lumps that often form along the tendons or joints of the wrists, hands, or feet. They are filled with a gel-like fluid and can vary in size. While they can be painless, they sometimes exert pressure on nearby structures, which might cause discomfort.

Ganglion cysts occur when the tissue surrounding a joint or tendon bulges out, forming a sac filled with fluid. Their association with tendons makes them particularly common in areas where tendons are present, providing a distinct characteristic that allows for their identification in clinical settings.

The other conditions mentioned do not relate to cystic tumors on tendons. Adhesive capsulitis, also known as frozen shoulder, involves inflammation and stiffness of the shoulder joint but does not involve cystic tumors. Osteoarthritis is a degenerative joint disease that primarily affects the cartilage in joints rather than developing cystic structures. Sciatica refers to the pain that radiates along the path of the sciatic nerve, typically due to compression or irritation, and is not associated with cystic tumors. Thus, ganglion is the specific condition that fits the description correctly.