Hygroma is a lumped tumor-like formation filled with serous-fibrinous or serous-mucosal fluid. It is located next to joints or tendon sheaths. Small hygromas usually do not cause any inconvenience other than aesthetic. When they are enlarged or located next to the nerves, pain appears; in some cases, sensitivity may be impaired. Pathology is diagnosed taking into account the data of anamnesis and physical examination. Conservative therapy is ineffective, surgical treatment is recommended – removal of hygroma.
M71.3 Another cyst of the synovial sac
Hygroma is a benign cystic tumor consisting of a dense wall formed by connective tissue and viscous contents. The contents look like transparent or yellowish jelly, and by nature is a serous liquid with an admixture of mucus or fibrin. Hygromas are associated with joints or tendon sheaths and are located near them. Depending on the localization, they can be either soft, elastic, or hard, resembling bone or cartilage in density.
Hygromas account for approximately 50% of all benign tumors of the wrist joint. The prognosis for hygromas is favorable, however, the risk of relapse is quite high compared to other types of benign tumors. In women, hygromas are observed almost three times more often than in men. At the same time, the vast majority of cases of their occurrence occur at a young age – from 20 to 30 years. In children and the elderly, hygromas develop quite rarely.
The causes of the pathology have not been fully clarified. In traumatology and orthopedics, it is assumed that hygroma occurs under the influence of several factors. It has been established that such formations appear more often in blood relatives, that is, there is a hereditary predisposition. In slightly more than 30% of cases, the occurrence of hygroma is preceded by a single injury. Many researchers believe that there is a connection between the development of hygroma and repeated traumatization or constant high stress on the joint or tendon.
Theoretically, a hygroma can appear anywhere where there is connective tissue. However, in practice, hygromas usually occur in the distal extremities. The first place in prevalence is occupied by hygromas on the back surface of the wrist joint. Less common are hygromes on the palmar surface of the wrist joint, on the hand and fingers, as well as on the foot and ankle joint.
It is widely believed that hygroma is a common protrusion of an unchanged joint capsule or tendon sheath, followed by infringement of the isthmus and the formation of a separately located tumor-like formation. This is not entirely true.
Hygromas are really connected with joints and tendon sheaths, and their capsule consists of connective tissue. But there are also differences: the cells of the hygroma capsule are degeneratively altered. It is assumed that the root cause of the development of such a cyst is metaplasia (degeneration) of connective tissue cells. In this case, two types of cells arise: one (fusiform) forms a capsule, the other (spherical) are filled with liquid, which is then emptied into the intercellular space.
That is why conservative treatment of hygroma does not provide the desired result, and after operations there is a fairly high percentage of relapses. If at least a small area of degeneratively altered tissue remains in the affected area, its cells begin to multiply, and the disease recurs.
Initially, a small localized tumor appears in the area of the joint or tendon vagina, usually clearly visible under the skin. Usually hygromas are single, but in some cases there is a simultaneous or almost simultaneous occurrence of several hygromas. There are both very soft, elastic, and solid tumor-like formations. In all cases, the hygroma is clearly delimited. Its base is tightly connected to the underlying tissues, and the remaining surfaces are mobile and not soldered to the skin and subcutaneous tissue. The skin above the hygroma shifts freely.
When pressure is applied to the area of the hygroma, acute pain occurs. In the absence of pressure, symptoms may vary and depend on the size of the tumor and its location (for example, the neighborhood of nerves). There may be constant dull pains, radiating pains or pains that appear only after intense exercise. In about 35% of cases, hygroma is asymptomatic. Quite rarely, when the hygroma is located under the ligament, it can remain unnoticed for a long time. In such cases, patients go to the doctor because of pain and discomfort when bending the hand or trying to grasp an object with their hand.
The skin above the hygroma can both remain unchanged and become rough, acquire a reddish hue and peel off. After active movements, the hygroma may increase slightly, and then decrease again at rest. Both slow, almost imperceptible growth and rapid increase are possible. Usually the size of the tumor does not exceed 3 cm, but in some cases the hygromas reach 6 cm in diameter. Self-resorption or spontaneous autopsy is not possible. At the same time, hygromas never degenerate into cancer, the prognosis for them is favorable.
Certain types of hygromas
Hygromas in the area of the wrist joint usually occur on the back side, on the lateral or anterior surface, in the area of the dorsal transverse ligament. As a rule, they are clearly visible under the skin. When located under the ligament, the tumor-like formation sometimes becomes visible only with strong flexion of the hand. Most of these hygromas are asymptomatic and only some patients experience minor pain or discomfort when moving. Less often, hygromas appear on the palmar surface of the wrist joint, almost in the center, slightly closer to the radial side (the side of the thumb). They can be soft or densely elastic in consistency.
On the back of the fingers, hygromas usually occur at the base of the distal phalanx or interphalangeal joint. The skin over them is stretched and thinned. A small dense, rounded, painless formation is detected under the skin. Pain appears only in some cases (for example, with a bruise).
On the palm side of the fingers, hygromas are formed from the tendon sheaths of the flexors. They are larger than the hygromas located on the back side, and often occupy one or two phalanges. As the hygroma grows, it begins to put pressure on numerous nerve fibers in the tissues of the palm surface of the finger and nerves located on its lateral surfaces, therefore, with such localization, severe pain is often observed, resembling neuralgia in nature. Sometimes a fluctuation is detected during palpation of the hygroma. Less often, hygromas occur at the base of the fingers. In this department, they are small, the size of a pinhead, painful when pressed.
In the distal (far from the center) part of the palm, hygromas also arise from the tendon sheaths of the flexors. They differ in small size and high density, therefore, when examined, they are sometimes confused with cartilage or bone formations. At rest, they are usually painless. Pain appears when trying to grasp a hard object tightly, which can interfere with professional activity and cause inconvenience in everyday life.
On the lower extremity, hygromas usually appear in the area of the foot (on the back surface of the metatarsal or fingers) or on the antero-outer surface of the ankle joint. As a rule, they are painless. Pain and inflammation can occur when rubbing the hygroma with shoes. In some cases, the pain syndrome appears due to the pressure of the hygroma on a nearby nerve.
Usually, the diagnosis of hygroma is made on the basis of anamnesis and characteristic clinical manifestations. To exclude osteoarticular pathology, radiography may be prescribed. In doubtful cases, ultrasound, magnetic resonance imaging or hygroma puncture are performed. Ultrasound examination makes it possible not only to see the cyst, but also to assess its structure (homogeneous or filled with fluid), determine whether there are blood vessels in the hygroma wall, etc. If nodular formations are suspected, the patient may be referred for magnetic resonance imaging. This study allows us to accurately determine the structure of the tumor wall and its contents.
Differential diagnosis of hygroma is carried out with other benign tumors and tumor-like formations of soft tissues (lipoma, atheroma, epithelial traumatic cyst, etc.), taking into account the characteristic location, the consistency of the tumor and the patient’s complaints. Hygromas in the palm area sometimes have to be differentiated with bone and cartilage tumors.
Pathology is treated by surgeons and orthopedic traumatologists. In the past, hygroma was tried to be treated by crushing or kneading. A number of doctors practiced punctures, sometimes with simultaneous administration of enzymes or sclerosing drugs into the hygroma cavity. Physiotherapy, therapeutic mud, bandages with various ointments, etc. were also used. Some clinics still use these methods, but the effectiveness of such therapy cannot be called satisfactory.
The percentage of relapses after conservative treatment reaches 80-90%, while after surgical removal, hygromas recur in only 8-20% of cases. Based on the presented statistics, the only effective method of treatment today is surgery. Indications for surgical treatment:
- Pain during movement or at rest.
- Limitation of the amount of movement in the joint.
- Unsightly appearance.
- Rapid growth of education.
Surgical intervention is especially recommended for the rapid growth of hygroma, since excision of a large formation is associated with a number of difficulties. Hygromas are often located next to nerves, vessels and ligaments. Due to the growth of the tumor, these formations begin to shift, and its isolation becomes more laborious. Sometimes surgical intervention is performed on an outpatient basis. However, during the operation, it is possible to open the tendon vagina or joint, so it is better to hospitalize patients.
The operation is usually performed under local anesthesia. The limb is exsanguinated by applying a rubber tourniquet above the incision. Exsanguination and injection of anesthetic into the soft tissues around the hygroma makes it possible to clearly define the boundary between tumor-like formation and healthy tissues. With complex localization of hygroma and large formations, it is possible to use anesthesia or conduction anesthesia. During the operation, it is very important to isolate and excise the hygroma so that even small areas of altered tissue are not left in the incision area. Otherwise, the hygroma may recur.
The tumor-like formation is excised, paying special attention to its base. The surrounding tissues are carefully examined, small cysts are isolated and removed when detected. The cavity is washed, sutured and the wound is drained with a rubber graduate. A pressure bandage is applied to the wound area. The limb is usually fixed with a plaster splint. Immobilization is especially indicated with large hygromas in the joints, as well as with hygromas in the fingers and hands. The graduate is removed 1-2 days after the operation. The stitches are removed for 7-10 days.
In recent years, along with the classical surgical technique of excision of the hygroma, many clinics have been practicing its endoscopic removal. The advantages of this method of treatment are a small incision, less tissue injury and faster recovery after surgery.