Image Quiz

Cortical Erosion of the Distal Parts of the Radius and Ulna in a Sixteen-Year-Old Boy with Hemophilia1 (continued)

Answer: Hemophilic pseudotumor of the left forearm.

The factor-VIII level was 30%. After administration of factor-VIII replacement, the ruptured cyst, which extended down to the bone and compressed and displaced all of the volar structures in the distal third of the forearm, was evacuated (Fig. 3). A forearm fasciotomy and decompression of the median nerve was performed concomitantly. The skin was loosely closed, and, after administration of antibiotics for three days and administration of 50 units of factor VIII every twelve hours for two weeks, the wound healed without complications. The finger contractures responded to physiotherapy (Figs. 4-A and 4-B). Two and one-half years postoperatively, the patient had only a mild residual fixed flexion contracture of the proximal interphalangeal joint of the index finger. Radiographs made at that time showed that the pseudotumor had resolved (Fig. 5).


Fig. 3		 Fig. 3 Intraoperative photograph following excision of the pseudotumor.

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Fig. 4-A
Fig. 4-B		 Fig. 4-A At two and a half years after the operation, there was a full range of flexion of the interphalangeal and metacarpophalangeal joints.
Fig. 4-B There was slight residual deformity of the distal interphalangeal joint of the index finger.

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Fig. 5		 Fig. 5 At two and a half years after the operation, anteroposterior (left) and lateral (right) radiographs showed filling of the erosion and extensive remodeling.

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Discussion

Although the lesion described in this paper occurred in a patient with a factor-VIII level of 30%, pseudotumors associated with hemophilia are rare, with a rate of about 1% to 2% in patients with severe hemophilia.

Clinically, an enlarging mass in a limb or the pelvis of a patient with hemophilia that fails to respond to replacement therapy in the absence of antibody formation to factor VIII or IX suggests a pseudotumor. Koepke and Brower reported a case in which a chondrosarcoma of the left scapula in a patient with hemophilia was treated as a pseudotumor but recurred six months later. A biopsy revealed chondrosarcoma, and the patient was treated with amputation. Whether this was truly a malignant tumor is uncertain, but it indicates that pathological changes in hemophilic blood cysts can closely resemble those of tumors—thus, the name pseudotumor.

The etiology of pseudotumors is obscure. Ghormley and Clegg suggested a subperiosteal extension of hemorrhage. Silber and Christensen as well as Abell and Bailey attributed pseudotumors to intraosseous bleeding with pressure necrosis of bone. Fernandez de Valderrama et al. thought that they were the result of bleeding into large muscle masses in areas where there was a rich periosteal blood supply to the bone. Fraenkel et al. noted rapid refilling of the cysts after aspiration and postulated that the original etiology might be a small arteriovenous aneurysm, but they found no evidence in support of this theory. Hilgartner and Arnold stated that one type of hemophilic pseudotumor may be caused by arteriovenous fistula.

Three distinct lesions were described by Fernandez de Valderrama. The first and simplest form is bleeding within muscle, causing nerve and blood vessel compression but no radiographic evidence of bone involvement. The second type develops in muscles with extensive periosteal attachment and results in thinning of cortical bone. In the third type, subperiosteal hemorrhage causes periosteal stripping and cortical destruction.

Before factor VIII was available, the outcome of treatment of pseudotumors was poor, with a mortality rate of up to 50%. If the pseudotumor is not treated, the limb may be threatened as the enlarging tumor compresses nerves and vessels. The prognosis is better for younger patients. Gilbert distinguished between two types of pseudotumors: a proximal type situated in the pelvis or femur and a distal type localized in the hand or foot. The former occurs in adults and is associated with a poor prognosis, and the latter occurs in children and has a better prognosis. Rapidly growing lesions in the distal part of the skeleton in children usually respond better to nonoperative treatment, whereas slowly growing lesions in the proximal part of the skeleton in adults usually lead to bone erosions and fail to respond to conservative treatment.

Radiation therapy has been recommended, but the results are controversial. Gilbert stated that radiation therapy has proven unsuccessful for established cases of pseudotumor of the pelvis and femur. Recently, Caviglia et al. recommended percutaneous treatment of hemophilic pseudotumors. They reported that they begin by giving factor-VIII replacement for six weeks in adults and twelve weeks in children. Regression by >50% is regarded as improvement and a positive response to conservative treatment. Regression by <50% is an indication for surgery in children. Adults receive factor VIII for another six weeks, and regression by 25% is a sign of response. If regression is <25%, then surgery is indicated. A small pseudotumor (<3 cm) can be aspirated and filled with fibrin glue, a locally hemostatic agent that is a mixture of fibrinogen, thrombin, a fibrinolysis inhibitor, and calcium, which are originally in separate vials. When mixed, they form a viscous solution that sets into an elastic coagulum to seal and fill the cavity. If there is more than one cavity of the pseudotumor, each must be aspirated. For larger pseudotumors, a small incision is made, the cavity is drained with a laparoscopic cannula, and the cavity is filled as described above. In pseudotumors of bones, the cavity should be opened, débrided, and filled with lyophilized bone graft or bone substitute.

Bone involvement and unresponsiveness to conservative treatment are indications for surgical management. The most effective treatment for pseudotumors with osseous involvement is surgical evacuation and resection in association with factor-VIII replacement therapy. This approach was successful in our patient.

Reference

1. Shaheen S, Alasha E. Hemophilic pseudotumor of the distal parts of the radius and ulna. A case report. J Bone Joint Surg Am. 2005;87:2546-9.