Cyst:
P.K. Ghatak, MD
What is a Cyst:
A cyst is a closed sac found anywhere in the body that may contain fluid or any other material - pus, blood, air/gas, or other substances. A cyst has a complete wall, and the wall may be composed of one or more layers. The fluid-filled cysts, in general, have an epithelial lying. Cyst, unable to drain its content because it had no duct.
Types of Cysts:
1. Congenital. 2. Infective. 3. Retention. 4. Malignant.
Congenital Cysts: Examples are Renal, Hepatic, Intestinal cysts,
How congenital cysts develop. - Those organs, like the liver and kidneys, have two sources of origin during the embryonic stage. In the end, two developed structures are joined together and the partition wall is absorbed, making it a functional organ. When one or more points of union between them fail to disappear, fluid accumulates. In the case of the liver, bile accumulates and urine in the case of simple renal cysts.
Infective Cysts: Example - Lung abscess.
Any infectious or Inflammatory process begins with the accumulation of WBCs, macrophages and platelets at the site of infection. To limit the spread of infection, the cellar layer acts as a barrier. This cell wall is gradually replaced by a fibrous wall. The enzymes released from the inflammatory cells dissolve the cells into a paste called Pus. This pus filled cystic structure is known as an abscess.
Retention Cysts: Example – Salivary cysts.
Inside the mouth, salivary glands of various sizes are present. One of the salivary gland ducts may be injured by dentures, fish bone, or chicken bone. An inflammation begins and the wound heals by fibrosis. Fibrosis may completely block the duct and saliva accumulates results in a cyst formation
Malignant Cysts: Example – Cystadenoma of the nasal sinuses and lungs.
One of the mucous glands of the sinus or lung may turn into a cancer. Some cancers retain glandular structures called cystadenoma, and other cancerous glands turn into anaplastic cancer.
Special cysts:
A few are discussed here.
Sebaceous cysts.
Sebaceous cysts arise at the dermatomal junction due to accidental invagination of sebum secreting cells under the surface skin layer. The common sites are the temple, head and back.
These cysts are slow growing and painless. The wall is thick and fibrous and as a cyst grows it raises the overlying skin. The cyst contains sebum. It looks like soft cheese and has an offensive odor. The cyst is attached by a long stock to the deeper later of the dermatome or to the suture lines of craniofacial bones.
Dermatomes junction where sebaceous cysts are seenHemorrhagic cyst of the liver.
There are several reasons for the development of hemorrhage inside a hepatic cyst. Some hepatic cysts are estrogen dependent and bleed when women are on birth control pills. There is a sudden increase in the size of the cyst and the tense cyst wall causes sudden upper abdominal pain. When a cyst ruptures, the pain intensifies and is felt over a wider area of the abdomen. Bleeding may not be controlled by itself and patients may go into shock. Immediate surgical intervention may be necessary.
Polycystic disease of the kidney.
This is an autosomal dominant mode of transmitted inherited disease. Patients are generally middle aged individuals, present with severe hypertension which is not controlled by medications. A kidney transplant is necessary to control BP. Ultrasound study of the abdomen is diagnostic and for confirmation, CT angiogram is generally performed. Polycystic liver is often associated with this condition.
Cysts of the peritoneal cavity. Several types of Cysts are present in the peritoneal cavity. A cyst may originate from the mesentery, peritoneum, or GI tract. Besides sonography, other images are necessary, including MRI to diagnose cysts of the peritoneum. Based of locularity, wall thickness, partition walls, consistency of content and presence of calcification may narrow the preoperative diagnosis. But at laparotomy a definitive diagnosis is often made – such a cyst may be serous, chylolymphatic, or lymphangioma.
Polycystic disease of the ovary.
If an ovary contains more than 20 cysts (follicles), it is termed polycystic ovary; if in addition, the woman has hirsutism and insulin resistance, an excess of androgen hormone activities and disruption of the anterior pituitary negative feedback loop then the condition is called Polycystic Ovary syndrome. It is an autosomal dominant inherited disease. Patients have scant menstruation, infertility, facial and body hair of male pattern, diabetes mellitus2, hypertension, obesity and more incidence of cardiovascular disease. If not properly treated, generally develop endometrial carcinoma.
6. Chocolate cysts of Ovary.
In endometriosis, the endometrial tissue may be deposited on the ovaries. The autoimplant tissues grow into cysts and bleed inside coincide with menstruation. These cysts are dark and are relatively large.
Hydratic cysts. Echinococcus is the tapeworm infects dogs, seeps and nearly all wild carnivorous mammals. In the dog's feces, infective cysts are present. When dogs' feces contaminate food and drinks and humans sallow these infected cysts, the larvae emerge in the stomach and spread out in various organs. Because humans are not definitive hosts, these larvae can not develop further and become cysts but continue to grow and produce daughter cysts and become multilocular cysts. The burden of the parasitic cysts is borne by the liver, lungs, muscles and brain. As these cysts grow, they produce obstruction of the flow of bile in the case of the liver and produce obstructive jaundice. In the brain, obstructed CSF (cerebrospinal fluid) circulation results in Hydrocephalus. Increased intracranial pressure becomes a serious medical problem. To cure, one or other surgical produces are required.
Cysticercosis. Tenea solium is a tapeworm and it infects pigs. Infected animal muscles and tissue containing many infective cysts. When uncooked or lightly cooked meat humans ingest, these cysts hatch into larvae and the larvae are carried by blood to the liver, brain and other tissues. In these organs, the larva develops into cysts. Like hydratic cysts cysts are multilocular and increase intracranial pressure. Usually, in untreated cases, the walls of the cysts are calcified.
Amoebic cystic abscess of liver and lungs. In tropical countries, humans are frequently infected by Entamoeba histolytica. Amoebic dysentery is the usual manifestation and amoeba burrows in the wall of the colon, producing colon ulcers and colitis. Occasionally amoeba are carried by blood to the liver and a liver abscess is formed. Adhesion develops between the upper surface of the right lobe of the liver and the right dome of the diaphragm. Amoeba enters the pleural cavity and produces empyema and also lung abscesses.
Hydrocele. The covering of the testicle, which maintains fluid content. When fluid balance is disrupted and excess fluid accumulates in the testicular sac, it is called a hydrocele. Surgery is required to cure.
Meningocele. Meningocele is a neural tube defect that develops during the early embryonic stage. Various degrees of severity, from simple meningocele with cerebrospinal fluid cysts associated with no neurological symptoms to herniation of the brain tissue with neurological complications, are seen. Treatment is surgical.
12. Myelomeningocele. The spinal neural arch fails to close completely and the condition is called spina bifeda. It is often associated with herniation of spinal nerve tissues and CSF. The condition is called Myelomeningocele. Various degrees of neurologic defects and urinary symptoms are usual. Treatment is surgical but significant debilities remain after a successful surgery.
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