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Home , Ganglion cyst

EXCISION OF THE GANGLION

Craig A. Camasta, DPM

INTRODUCTION the . Therefore, the lesions are believed to be reactive and not neoplastic. The first description of the is credit- ed to Hippocrates, who described these lesions as PATHOGENESIS "...flabby ganglionic tumors, containing only mucoid flesh..." Interestingly, this original descrip- The pathogenesis of ganglion cyst formation has tion was quite accurate, and little more has been been widely debated over the last century. The discovered about these masses in most commonly accepted theory is the "hernial recent medical times. hypothesis." This theory describes the formation Ganglion have been reported exten- of a ganglion cyst as an out-pouching or disten- sively in the medical literature. Controversy, with tion of a weakened portion of a capsule or respect to the pathogenesis of these lesions is tendon sheath. This theory is supported by the reflected in the variety of terms used to describe fact that these lesions occur in close proximily to them, as many synonymous terms have been tendons and , and microscopic analysis of used to describe a similar condition. (Table 1) the cyst wall and fluid within the cyst closely resemble normal anatomy of tendosynovial tissue and joint fluid. Controversy as to whether or not Table L there is direct communication with a joint capsule or tendon sheath has been the main opposition to TERMS FOR GA]\GLION CYSTS this theory, as surgical exploration of these lesions Ganglion does not consistently demonstrate a direct com- Ganglion Cyst munication. Ganglionic Cyst Various diagnostic studies have been per- Bursal Cyst formed which support this theory, most notably Synovial Cyst Arthrography and Gangliography. In these stud- Tendosynovial Cyst ies, a radiopaque contrast dye has been injected Baker's Cyst into either the cyst itself (Gangliography), or the Cystic Myxoma suspected communicating joint capsule (Arthrog- raphy). Dye injected into a cyst does not usually demonstrate retrograde flow into a joint capsule, Ganglion cysts are benign, tumor-like lesions however, when a contrast dye is injected into the which contain a translucent, viscous fluid and are suspected adjacent joint capsule, there is fre- derived from tendo-synovial tissue. The appear- quently demonstrated communication with the ance of these cystic lesions has been attributed to cyst. An explanation to this observed pattern is inflammatory conditions which cause effusion of that of the "valve phenomenon," where there

181 exists a pressure differential within the potential The microscopic anatomy of the cyst wall space of a joint capsule that encourages effusion reveals a structural similarity to the normal lining of the contrast dye into the cyst. This unidirec- of a tendon sheath or ioint capsule. The wall con- tional flow of fluid, based on differentiai pres- sists of collagen-rich fibrous tissue of varying sures of the fluid in the cyst and joint fluid, pre- thickness, which is lined by fibroblasts and is vents the low pressure cystic fluid from secretory in nature. The fluid within the cyst, re-entering the joint capsule. This theory is also which is synthesized by fibroblasts, is clear to suppofied by the frequently obserwed enlarging of amber colorecl, and may appear hemorrhagic sec- a cyst following an increase in activity, such as ondary to trauma. The fluid is gelatinous in tex- ambulation. In addition, the observed refilling of ture, and contains and a ganglion cyst following aspiration supports this mucopolysaccharides, resembling the ioint fluid of theory, as there is a persistent communication an inflammatory condition. through a stalk or pedicle. Three stages of ganglion cyst development have been described. The stage of formation LOCATION occurs when the cyst first appears, with the lesion being hard, tense, and tender. The stationary Ganglion cysts are commonly observed in associ- phase is marked by the enlargement and reduc- ation with the joints and tendons of the appendic- tion of the cyst's size based on activity level, and ular skeleton. The cysts are frequently found in the stage of diminution follows with softening of communication with the multiple small joints of the cyst and occasional, gradual disappearance. It the hand and (88%), and the and has been reported that up to one-half of all gan- (770/i). In addition, superficial tendons in these glion cysts spontaneously disappear with time. anatomic locations are frequently subject to local trauma, and can be the site of ganglion cysts aris- ing from a tendon sheath. In the foot and ankie, the most common sites of ganglion cysts are the The patient, with a ganglion cyst, typical presents anterior ank1e, sinus tarsi, dorsum of the foot with localized swelling with or without accompa- (great tarsal synovial cavity), and extensor tendon nying pain. Pain is usually secondary to a space- sheaths. It has been reported that more than one- occupying condition, and may present as a simu- third of all patients with ganglion cysts relate the lated compartment syndrome, sinus tarsi, or tarsal appearance of the cyst with a local trauma or an tunnel syndrome. In cases where the lesion is in increased use of the part in question. close proximiry to a peripheral nelwe, the patient The female to male ratio has been reported may present with a neuropraxia or neuritis-type to be from 2-J:1., and 70-750/o of all patients with a pain. These lesions may also cause difficulty in ganglion cyst report a bilateral condition. The finding shoes that fit. Palpation reveals an average size of the lesion is 2.0 cm, and excised extremely hard to fluctuant mass, which is often cysts have been measured in excess of 5.0 cm. movable beneath the skin. In addition, the overly- Less frequently, intraosseous ganglion cysts have ing soft tissue and integument is usually freely also been described, as either solitary iesions, or mobile over the mass. in association with overlying soft tissue cysts. DIAGNOSIS COMPONENTS, ANATOMY, AND The diagnosis of a ganglion cyst is one which is OF DEYELOPMENT STAGES made through a combination of assessment Ganglion cysts may appear as either a solitary, modalities. As with any mass of unknown origin, fluid-filled mass, or they may be multi-lobed or a list of differentials must be considered and sys- multilocular. There may be ganglial pseudopods, tematically ruled out, based on the frequency of which are cystic offshoots from the main cyst, or their appearance in a particular anatomic location. smaller microcysts which are present belween the (Table 2') main cyst and the ioint capsule or tendon sheath.

1,82 where the lesion is associated with a superficial Table 2 tendon, the mass may move with the tendon upon range of motion examinaiion. COMMON SOFT TISSUE AND OSSEOUS LESIONS Transillumination Soft Tissue Osseous Depending on whether or not the mass has perfo- Rursae rated through the deep facial layer, an osseous Epidermal Inclusion Cyst Unicameral Bone Cyst lesion may be suspected. However, when the Neuroma Giant Cell Tumor lesion appears as a superficial structure, an addi- Benign tional test may be performed to determine Chondroblastoma whether or not the mass is fluid filled. Transillu- Fibrous Dysplasia mination of the mass can be performed with little Mlxoma Enchondroma discomfort to the patient, using a penlight to pro- Xanthoma Brodie's Abscess vide a narrow beam of light. In a dimly lit exami- Gouty Tophus Subchondral nation room, it is possible to view the light as it Bone Cyst passes through the fluid-fi11ed lesion. This test can Benign Synovioma help differentiate between a fluid-filled and a Giant Ce1l Tumor (PVS) more dense structure. \X/e11-Demarcated EDB Muscle Radiography Plain film or soft tissue sensitive radiography can be performed as an adjunctive study to determine In addition to this list, one must also suspect if there is an osseous strllcture producing the a lesion of vascular origin, such as a thrombosed observed findings. Secondarily, arthritic conditions superficial vein. may predispose to joint and it is not A thorough and detailed history of the pre- uncommon to obserue osteophytic formation of sentation of the lesion will direct the examination. adjacent joint surfaces in cases where a ganglion Special attention should be paid to the onset of cyst protftrdes from an afihritic joint. This fact is symptoms and the subsequent course of tl-ie also important in preoperative planning, as the lesion. The patient may recal7 a history of trauma stalk or pedicle of the cyst is often not directly to the area, or increased activity prior to the onset beneath the central portion of the mass. As an of symptoms. The patient often notices that the out-pouching of a joint capsule or tendon sheath, mass enlarges after ambulation, and decreases in these lesions will follow the path of least resis- size with inactiviry. tance and may be directed away from the The location of the lesion is also important involved tendosynovial communication. A surgical in the diagnosis of a ganglion cyst, especially if attempt to locate the stalk may be aided 1f a par- the mass presents on the dorsum of the foot or ticular joint is suspected, thus directing incision anterior ankle region. The extensor tendons and placement and subsequent dissection. peroneal tendons are also common sites of involvement, as the tendons in this region of the MRI foot are superficial structures which are prone to If a more obscure lesion is suspected, or if the blunt trauma and irritation from shoes. extent of the mass is in question, a magnetic reso- The history and location of the lesions will nance image (MRI) can be obtained to further direct the initial , however, characterize the lesion. MRI offers superb resolu- the physical examination will prove more benefi- tion of soft tissue densities, and should be consid- cial in making an accurate diagnosis. Palpation of ered to be the definitive non-invasive diagnostic the mass often reveals a subcutaneous mass test. Since these cystic lesions are fluid filled, an which is not adherent to the overlying integu- increased signal on the T-2 weighted image, ment. The mass may be firm to soft in texture and which is similar to that which is seen in synovial may fluctuate upon laleral palpation. In cases fluid, would be expected.

IB3 Gangliography technique is no longer advocated due to the Another diagnostic tool in the evaluation of a gan- potential effects of radiation exposure. glion cyst is the use of a radiopaque contrast dye. Gangliography is a method of evaluating the size Semi-Invasive and extent of a ganglion cyst, and is performed as A variety of non-surgical, semi-invasive tech- an adjunct to aspiration. After the injection of a niques that have been used diagnostically, can feu. milliliters of contrast dye, a radiograph is also be used therapeutically to treat ganglion obtained, and the extent of the lesion is more eas- cysts. These techniques foctts around the use of ily visualized. This method has also been used to cyst aspiration, either as a solitary means of demonstrate the relationship between a ganglion reducing the fluid content within a cyst, or in cyst and the adjacent ioint capsule through a com- combination with adjunctive modalities such as municating stalk. However, this observation is the injection of agents intended to reduce the variable since the "valve phenomenon" prevents inflammatory condition. The most commonly retrograde flow of the dye back into the joint. used agent is a 1ocal acting corticosteroid, which Arthrography, or the injection of a contrast medi- is usually a combination of long and short acting um into the adjacent articular capsule, is more substances (acetate and phosphate). These tech- likely to demonstrate communication through a niques provide cure rates from 40-860%, however stalk, due to the pressure differential which exists most of these studies have been reported with between the potential space of a joint capsule and ganglion cysts of the hand and wrist. The proce- the out-pouching cyst. A positive study, demon- clure is performed in an office setting under local strating communication with the cyst, is predicat- anesthesia, under sterile conditions. A large bore ed on the placement of the contrast medium into needle (72-78 gauge) in combination with a large the correct joint, which may be difficult in cases syringe (20 cc) aids in the evacuation of the cyst. where the cyst overlies multiple small joints. Both Since these cystic lesions are often multi-lobed (or studies carry the risk of an allergic reaction to the multilocular), it is important to redirect the needle contrast dye and arthrography carries a greater in several planes to ensure penetration and evac- risk of infection. Llation of all cavities. This technique can be facili- tated by the use of laterai compression from an TREATMENT assistant, thus increasing the intralesional pres- sure. The collected fluid is then submitted for Conservative cltologic examination, and a compression dress- The treatment of ganglion cysts can be divided ing applied. Several variations to this method into conselative, serni-invasive, and surgical cate- have been described in the literature, such as gories. Historically, the prelerred method for treat- injecting a sclerosing agent or hyaluronidase, ment of a ganglion cyst involved using a sharp either in combination with cofiicosteroids, or as a blow with a heary object to burst the mass. A solitary means of treatment. Another method book was commonly used, and the Bible appears describes needle irritation of the inner lining of to have been favored for this procedure. the cyst wall to encourage fibrosis and prevent Joint inflammation appears to aggravate and fecurrence. stimulate the enlargement of ganglion cysts, thus Another technique described involves the it is reasonable to suspect that immobilization of placement of a transfixation suture around the the involved part will provide relief. In addition, cyst, followed by daily retraction of the suture. biomechanical support through the use of an The risk of infection was the maior contraindica- orthosis has been advocated in reducing the tion to the use of this technique. inflammatory state. Applying digital pressure to the cyst has been described as a means of reduc- Surgical ing the size of ganglions in the wrist, with this Surgical excision of the ganglion cysts remains the technique providing a 56o/o cure rate. Radiothera- mainstay of treatment, with the most common py has also been used historically, however this complication being recurrence. The cure rate from

r84 surgical excision ranges from 75-850/0. The use of SUMMARY a properly placed incision will facilitate a layered surgical exposure. Surgical exposure should not The ganglion cyst is a common soft tissue mass be limited at the expense of an incomplete exci- which presents in a variety of anatomic locations sion. A tourniquet can be used to aid in hemosta- in the foot and ankle. It is one which will chal- sis, thus providing a dry surgical field. Meticulous lenge even the most experienced diagnostician, in dissection with the use of fine instruments rvil1 aid that it often presents in uncommon locations and in the location of the communicating stalk, which with varied symptoms. Although benign in nature, should be exposed and ligated with an appropri- the differential diagnosis of a ganglion cyst is ate suture. Maintaining the integrity of the cyst's quite extensive and must be systematically evalu- wall will prevent ftipture of the cyst and extrava- ated. Treatment of the ganglion cyst varies from sation of its contents. This rupture is the most conservative to surgical, and is patient specific. common intraoperative complication. Rupture of Through careful surgical dissection, location and the cyst can prevent the surgeon from delineating extirpation of the communicating sta1k, presefl/a- the margins of the mass, and can lead to an tion of vital structures, and a layered closure of incomplete excision and a greater chance of tissue planes, the chance of recurrence will be recurrence. In cases where a stalk is identified greatly reduced. protruding from a joint capsule, it is not uncom- mon to obserye osteoph),tic formation from adja- BIBLIOGRAPTTY cent articular surfaces. this setting, appropriate In Light N{, Pr-rpp G: Ganglions of the Sinus Txsr../ Foctt Surg 30G):350- osseous resection is warranted. 355.1991. A layered closure will eliminate dead space Ly PN, \lcCarq, J\4: Gangliogr aphy. J F'oot Sutg 31(1'):52-56. 7992. \'lr.rdc1u BN. \Iorns IIA. Fahn.r' NR\'I: The Treatment of Ganglia. / formation and reduce the chance of hematoma Bane.[oilt. Sutg (Br') -2(B):1.i]. 1990. formation. In addition, reapproximation of the \clson CL. Sas'miller S. Phalen GS: Ganglions of the \i'rist ancl Hand. J Bone ./oint SLog i4(A),1459 1161, 7{)i2. deep facial layer will act as an anatomic barrier to Potter GK, Ward KA: Tumors. In McGlarnry ED, Banks AS, Don'ney subsequent recuflent cyst formation. The inlection NIS (eds): Comprebensiue Textbook of Foot Surgery. Baltimore N{D. Villiams & Wilkins, 1992. pp. 1151-11,51. of a short-acting corticosteroid agent can reduce Przystawski N, McGarry JJ. Stern NIB, Edelman RD. Intratendinor.rs local inflammation, and an appropriate compres- Ganglion C:ist. J l-oot Surg28:G)214-218, 1989. C)'st. Am Podi.tlr Assoc sive dressing Rosenberg A. Dorsal Tenclo-sl,novial .J Med should be applied. 76(8):155 156, 1986. Rosson I\\'. \\-alker- G. The \atural Histon' of Ganglia in Chilclren. / ( r1(B B o trc .lo I I t t .!ir.q Br) ) r 107-;'08. 1 989. \'a|e l: \'ale.s Potliatic .lledicine. Tbird Ed. Yiilliams & \tu'ilkins, Bald- more l,{D, pp. 281 283, 1987.

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