Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
Dr. Balentine received his undergraduate degree from McDaniel College in Westminster, Maryland. He attended medical school at the Philadelphia College of Osteopathic Medicine graduating in1983. He completed his internship at St. Joseph's Hospital in Philadelphia and his Emergency Medicine residency at Lincoln Medical and Mental Health Center in the Bronx, where he served as chief resident.
A cyst is a closed capsule or sac-like structure, usually filled with liquid, semisolid, or gaseous material. Cysts usually occur within almost any type of the body's tissue; they vary in size from microscopic to large structures that can displace internal organs. Although cysts can also refer to any normal bag or sac formation in the body, in this article, we will use the definition stated above and consider it to be an abnormal formation. Consequently, the cysts discussed below are not normal parts of the body. They have distinct membranes or cyst walls. If the sac is filled with pus, it is usually considered an abscess, not a cyst.
Pilonidal cysts arise at the base of the tailbone (coccyx) of the lower back,
just above the natal cleft (the cleavage between the buttocks). Doctors
sometimes use the term pilonidal disease to refer to the range of problems that
can affect this area. In simple cases, a small, solitary cyst-like area
containing fluid is present without evidence of infection.