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.
There are hundreds of different types of cysts. Cysts can occur almost anywhere in the body. The majority of cysts are benign, but a few may contain malignant cells. The following cyst types may be found in the body:
Epidermoid (sebaceous) cyst: usually benign swelling in the skin arising in the sebaceous gland, typically filled with yellowish sebum
Breast cyst: a fluid-filled sac within the breast
Ganglion or synovial cyst: a non-neoplastic soft-tissue collection that may occur in any joint
Dermoid cyst: an abnormal growth containing epidermis, hair follicles, and sebaceous glands, derived from residual embryonic cells
Ovarian cyst: an accumulation of fluid within an ovary that is surrounded by a very thin wall
Baker cyst: a benign swelling of the membranous synovial bursa behind in the knee; also known as a popliteal cyst
Bartholin cyst: formed when a Bartholin gland (at the opening of the vagina) is blocked
Arachnoid cyst: a collection of cerebrospinal fluid covered by arachnoid cells and collagen that develops between the surface of the brain in the cranial base or on the arachnoid membrane
Epididymal cyst: extratesticular spherical cysts in the head of the epididymis
Labial cyst: any fluid-filled cyst in the labia
Pilonidal cyst: a cyst that contains hair and skin debris near or on the cleft of the buttocks; also known as jeep driver's disease
Nabothian cyst: a mucous-filled cyst on the surface of the cervix
Pineal cyst: a fluid-filled body in the pineal gland (of the brain)
Thyroglossal cyst: a fibrous cyst that forms from a persistent thyroglossal duct
Synovial cyst: also known as a ganglion cyst, is a soft tissue lump that may occur in any joint
Branchial cleft cyst: a cyst composed of epithelial cells that arise on the lateral part of the neck due to congenital failure of obliteration of the second branchial cleft
Choroid plexus cyst: small cysts composed of cerebrospinal fluid trapped by spongy brain cells
Hydatid cyst: Echinococcus spp. tapeworm (larval stage) surrounded by epithelial cells in an organ
Corpus luteum cyst: a type of ovarian cyst that may persist after an egg has been released from a follicle
Colloid cyst: in the brain, a cyst containing gelatinous material
Mucous cyst: a thin sac containing clear fluid that may be found on the lips, mouth, and occasionally in other areas of the body
Pancreatic cyst: sac-like pockets of fluid within the pancreas; technically, they aren't cysts because they are lined with scar or inflammatory tissue
Testicular cysts: fluid-filled cysts in the testicles
Thyroid cysts: Also called a thyroid nodules, they may be fluid filled or contain some solid components; most are benign but a few may contain malignant components.
Liver cysts: thin-walled cysts that contain fluid; the majority are benign
Kidney cyst: walled-off fluid-filled areas within the kidney; some are congenital (polycystic disease)
Sinus cysts: abnormal tissue growth, usually in the maxillary sinuses, filled with liquid, air, or semisolid material
Acne cyst: aggregations of inflamed and clogged skin oil ducts; many are not cysts but are abscesses
Readers should note that many cysts types are not listed; the purpose of this article is to give the reader an introduction to the hundreds of types of cysts and is not meant to be all inclusive.