A ganglion cyst is a fluid-filled bump associated with a

joint A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...

tendon sheath A tendon sheath is a layer of synovial membrane around a tendon. It permits the tendon to stretch and not adhere to the surrounding fascia. It contains a lubricating fluid (synovial fluid) that allows for smooth motions of the tendon during muscl ...

. It most often occurs at the back of the

wrist In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; "The wrist contains eight bones, roughly aligned in two rows, known as the carpal ...

, followed by the front of the wrist. The cause is

unknown Unknown or The Unknown may refer to: Film and television Film * The Unknown (1915 comedy film), ''The Unknown'' (1915 comedy film), Australian silent film * The Unknown (1915 drama film), ''The Unknown'' (1915 drama film), American silent drama ...

. The underlying mechanism is believed to involve an outpouching of the

synovial membrane Synovial () may refer to: * Synovial fluid * Synovial joint A synovial joint, also known as diarthrosis, joins bones or cartilage with a fibrous joint capsule that is continuous with the periosteum of the joined bones, constitutes the outer bou ...

. Diagnosis is typically based on examination. The ability to shine through the bump or any past decrease in size supports the diagnosis of the bump as a ganglion cyst. Ganglion cysts are usually obvious upon observation.

Medical imaging Medical imaging is the technique and process of imaging the interior of a body for clinical analysis and medical intervention, as well as visual representation of the function of some organs or tissues (physiology). Medical imaging seeks to revea ...

may be considered on infrequent occasions to rule out another diagnosis. Treatment is not necessary. Options for treatment include needle aspiration or

surgery Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

. About half the time, they resolve on their own. About three per 10,000 people newly develop ganglion of the wrist or hand a year.

Presentation

The average size of these cysts is , but excised cysts of more than have been reported. The size of the cyst may vary over time. Between 50 and 70% of all masses on the hand and wrist are ganglion cysts.

Wrist

They commonly are found near the wrist joint, especially at the scapholunate area. Common wrist ganglions include: * dorsal wrist ganglion * volar wrist ganglion * extensor retinaculum ganglion * occult ganglion * intraosseous ganglion * mucous cyst

Foot

In a 2007 study of patients in

Glasgow Glasgow is the Cities of Scotland, most populous city in Scotland, located on the banks of the River Clyde in Strathclyde, west central Scotland. It is the List of cities in the United Kingdom, third-most-populous city in the United Kingdom ...

whose foot lumps were removed surgically, 39 of 101 cases were ganglion cysts. The study replicated earlier findings that no ganglion cysts were found on the sole or heel. The authors wrote, "Although lumps in these areas may be ganglia, the surgeon should probably consider other diagnoses in the first instance." The researchers noted a preponderance of occurrence among females (85%) and that 11 of the other cases had been misdiagnosed as ganglion cysts before surgery.

Lower extremity

Ganglion cysts are not limited to the hands and feet. They may occur near the

knee In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia (tibiofemoral joint), and one between the femur and patella (patellofemoral joint). It is the largest joint in the hu ...

, mostly within and near the

anterior cruciate ligament The anterior cruciate ligament (ACL) is one of a pair of cruciate ligaments (the other being the posterior cruciate ligament) in the human knee. The two ligaments are called "cruciform" ligaments, as they are arranged in a crossed formation. In ...

, but they may occur at the origins of the

gastrocnemius The gastrocnemius muscle (plural ''gastrocnemii'') is a superficial two-headed muscle that is in the back part of the lower leg of humans. It is located superficial to the soleus in the posterior (back) compartment of the leg. It runs from its t ...

tendon, and

anteriorly Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Thi ...

on Hoffa's infrapatellar fat pad. Most patients with a ganglion cyst of the knee present with both pain and a restricted range of motion, but these findings are variable, and some patients may have neither.

Other

From their common origin at a joint or tendon, ganglion cysts may form in a wide range of locations. At the shoulder, they typically occur at the acromioclavicular joint or along the biceps tendon, and are occasionally known to cause nerve compression or bone erosion. Rarely, intraosseous ganglion cysts occur, sometimes in combination with a cyst in the overlying soft tissue. It is possible for a cyst to be considerably displaced from the joint. In one extreme case, a ganglion cyst was observed to propagate extensively via the conduit of the

common peroneal nerve The common fibular nerve (also known as the common peroneal nerve, external popliteal nerve, or lateral popliteal nerve) is a nerve in the lower leg that provides sensation over the posterolateral part of the leg and the knee joint. It divides a ...

sheath to a location in the thigh; in such cases surgery to the proximal joint to remove the articular connection may remove the need for a riskier, more extensive surgery in the neural tissue of the thigh. The cysts may intrude into the spine, which may cause pain and

dysesthesia Dysesthesia is an unpleasant, abnormal sense of touch. Its etymology comes from the Greek word "dys," meaning "bad," and "aesthesis," which means "sensation" (abnormal sensation). It often presents as pain but may also present as an inappropriate, ...

in distant extremities. Cystic adventitial disease, in which a cyst occurs within the

popliteal artery The popliteal artery is a deeply placed continuation of the femoral artery opening in the distal portion of the adductor magnus muscle. It courses through the popliteal fossa and ends at the lower border of the popliteus muscle, where it branche ...

near the knee, has been proposed recently to occur by an articular mechanism, with a conduit leading from the joint, similar to the development of ganglion cysts, that spreads within the peroneal nerve. One uncommon location of the cysts are in the muscle tendons of the hand, such as the extensor digitorum superficialis. Cyst_Profile2.JPG, Cyst on right wrist Ganglion Cyst on Foot.jpg, Cyst on dorsum of right foot Kyste420.jpg, Cyst on a finger Ganglion Cyst On Right Index Finger.jpg, Small cyst on right index finger Ganglion_cyst_lanced.JPG, small cyst on thumb lanced with red-hot needle File:Ganglion Cyst on the palmar side of the left wrist.jpg, Ganglion cyst on the palmar side of the left wrist

Causes

The exact cause is unknown. The most commonly accepted probable cause of ganglion cysts is the ''

herniation A hernia (: hernias or herniae, from Latin, meaning 'rupture') is the abnormal exit of tissue or an organ, such as the bowel, through the wall of the cavity in which it normally resides. The term is also used for the normal development of the in ...

hypothesis,'' by which they are thought to occur as an out-pouching or distention of a weakened portion of a joint capsule or tendon sheath. This description is based on the observations that the cysts occur close to tendons and joints. The microscopic anatomy of the cyst resembles that of tenosynovial tissue. The fluid is similar in composition to

synovial fluid Synovial fluid, also called synovia, elp 1/sup> is a viscous, non-Newtonian fluid found in the cavities of synovial joints. With its egg white–like consistency, the principal role of synovial fluid is to reduce friction between the articul ...

. Dye injected into the joint frequently ends up in the cyst. Dye injected into the cyst rarely enters the joint, however, which has been attributed to the apparent formation of an effective and one-way "

check valve A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. Check valves are two-port valves, meaning they have ...

", allowing fluid out of the joint, but not back in. In synovials, post-traumatic degeneration of

connective tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...

and

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

have been considered as causes. Other possible mechanisms for the development of ganglion cysts include repeated mechanical stress,

facet Facets () are flat faces on geometric shapes. The organization of naturally occurring facets was key to early developments in crystallography, since they reflect the underlying symmetry of the crystal structure. Gemstones commonly have facets cu ...

arthrosis, myxoid degeneration of periarticular

fibrous tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesode ...

s and liquefaction with chronic damage, increased production of

hyaluronic acid Hyaluronic acid (; abbreviated HA; conjugate base hyaluronate), also called hyaluronan, is an anionic, nonsulfated glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. It is unique among glycosaminog ...

fibroblasts A fibroblast is a type of biological cell typically with a spindle shape that synthesizes the extracellular matrix and collagen, produces the structural framework ( stroma) for animal tissues, and plays a critical role in wound healing. Fibrobla ...

, and a proliferation of

mesenchymal cell Mesenchymal stem cells (MSCs), also known as mesenchymal stromal cells or medicinal signaling cells, are multipotent stromal cells that can differentiate into a variety of cell types, including osteoblasts (bone cells), chondrocytes (cartilage c ...

s. (original source cites eight additional references for the quoted paragraph)

Diagnosis

Ganglion cysts are diagnosed easily, as they are visible and pliable to touch. Ultrasonography ( US) may be used to increase diagnostic confidence in clinically suspected

lesion A lesion is any damage or abnormal change in the tissue of an organism, usually caused by injury or diseases. The term ''Lesion'' is derived from the Latin meaning "injury". Lesions may occur in both plants and animals. Types There is no de ...

s or to view smaller "

occult The occult () is a category of esoteric or supernatural beliefs and practices which generally fall outside the scope of organized religion and science, encompassing phenomena involving a 'hidden' or 'secret' agency, such as magic and mysti ...

" cysts as a cause of dorsal wrist pain with forceful extension.

Treatment

At least 33% resolve without treatment within six years, and 50% within 10 years. Surgical excision is the primary discretionary, elective treatment option for ganglion cysts. Alternatively, a

hypodermic needle A hypodermic needle (from Greek Language, Greek ὑπο- (''hypo-'' = under), and δέρμα (''derma'' = skin)) is a very thin, hollow tube with one sharp tip. As one of the most important intravenous inventions in the field of drug admini ...

may be used to drain the fluid from the cyst (via aspiration). The recurrence rate is about 50% following aspiration of a ganglion cyst.

Complications

Complications of treatment may include joint stiffness and scar formation. Recurrence of the

is more common following excision of a volar ganglion cyst in the wrist. Incomplete excision that fails to include the stalk or pedicle also may lead to recurrence, as will failing to execute a layered closure of the incision.

Prognosis

Recurrence rate is higher in aspirated cysts than in excised ones. Ganglion cysts have been found to recur following surgery in 12% to 41% of patients. A six-year outcome study of the treatment of ganglion cysts on the dorsal wrist compared excision, aspiration, and no treatment. Neither excision nor aspiration provided long-term benefit better than no treatment. Of the untreated ganglion cysts, 58% resolved spontaneously; the postsurgery recurrence rate in this study was 39%. A similar study in 2003 of ganglion cysts occurring on the palmar surface of the wrist states: "At 2- and 5-year follow-up, regardless of treatment, no difference in symptoms was found, regardless of whether the palmar wrist ganglion was excised, aspirated, or left alone."

Etymology

Being a

misnomer A misnomer is a name that is incorrectly or unsuitably applied. Misnomers often arise because something was named long before its correct nature was known, or because an earlier form of something has been replaced by a later form to which the nam ...

that has persisted into modern times, the ganglion cyst is unrelated to the neural

ganglion A ganglion (: ganglia) is a group of neuron cell bodies in the peripheral nervous system. In the somatic nervous system, this includes dorsal root ganglia and trigeminal ganglia among a few others. In the autonomic nervous system, there are ...

cell; its etymology traces back to the ancient Greek , a 'knot' or 'swelling beneath the skin', which extends to the neural masses by analogy. Generally,

Hippocrates Hippocrates of Kos (; ; ), also known as Hippocrates II, was a Greek physician and philosopher of the Classical Greece, classical period who is considered one of the most outstanding figures in the history of medicine. He is traditionally referr ...

is credited with the description of these cysts.

"Bible bump"

A historical method of treatment for a ganglion cyst was to strike the lump with a large, heavy book, causing the cyst to rupture and drain into the surrounding tissues. Historically, a Bible, usually the largest (or only) book in a household, was employed for this treatment. This practice led to the nickname of "Bible bumps" or "

Gideon Gideon (; ) also named Jerubbaal and Jerubbesheth, was a military leader, judge and prophet whose calling and victory over the Midianites is recounted in of the Book of Judges in both the Hebrew Bible and the Christian Bible. Gideon was th ...

's disease" for the cysts. This treatment risks injuring the person and thus is not recommended.

References

External links

American Academy of Orthopaedic Surgeons - Ganglions cyst of the wrist

{{DEFAULTSORT:Ganglion Cyst Dermal and subcutaneous growths Wikipedia medicine articles ready to translate Wikipedia emergency medicine articles ready to translate