Eye-opening: a case of hemophilic femoral pseudotumor with pathological fracture

The patient was a 39-year-old male

Physical examination: left thigh swelling, tenderness, limited movement, bone rubbing sensation (+), abnormal activity, purple foot, and good arterial pulse

Laboratory tests: plasma coagulation factor VIII activity was determined to be 13.

Film degree exam:

X-ray examination: Before the left femur was not fractured, an arc-shaped defect of the cortical bone in the middle of the femur along the long axis of the diaphysis was seen, with irregular edges and sclerosis.

Figure 1 Before the left femur was fractured, an arc-shaped defect of the cortical bone in the middle of the femur along the long axis of the diaphysis was seen.

Figure 2 Post-traumatic X-ray films showed that the defect of the cortical bone in the middle femur was fractured, the broken ends were displaced and overlapped, the localized soft tissue mass-like density was more obvious than before, the scope was slightly enlarged, the edge was clearer, and strip-like density was seen in the mass Heightened shadow, clear surrounding muscle space

CT findings: The bone window shows a limited defect of the cortical bone in the middle of the femur, the medial border is sclerotic, the edge is not regular, and the surrounding soft tissue is slightly hyperdense.

Figure 3 Enhanced scan shows that soft tissue mass is seen on the medial and lateral sides of the femur.

MRI manifestations: bone defect in the middle of the femur, the medial edge is sclerotic and regular, showing low signal; T1WI and T2WI around the bone cortical defect area showed irregular mixed signal mass shadow, T1WI mass showed equal and slightly low signal, and the film can be seen inside Slightly short T1 signal in strip shape, iso- and slightly high signal in T2WI mass, slightly short T2 and long T2 signal in patch, slightly high signal on STIRT2WI, and patchy low signal area inside

Figures 4-6 Figure 4 T1WI

CTA of the femoral artery showed that the middle part of the femoral artery was compressed and moved, but the femoral artery was not invaded, and irregular slender blood vessels were seen in the mass (Figure 7)

Figure 7 CTA of the femoral artery shows that the middle segment of the femoral artery is partially compressed and moved, the femoral artery is not invaded, and irregular slender blood vessels are seen in the mass

Pathology: (surgical resection of pseudotumor) Most of the tissues submitted for inspection were blood clots, with fibrous, fatty and striated muscle tissue in the focus, and some tissues showed degeneration, with diffuse and scattered inflammatory cell infiltration, mainly chronic inflammatory cell infiltration.

discuss:

Hemophilia is a genetic bleeding disorder that can be divided into three types: A, B, and C according to the lack of coagulation factors.

The mechanism of this lesion is bone and subperiosteal hemorrhage, which on the one hand causes periosteal hyperplasia, on the other hand, erodes the bone from outside the cortex, and spreads along the bone to form a pseudotumor; or continuous hemorrhage in the cortex and medullary cavity , increased intraosseous pressure, resulting in bone destruction and absorption, the formation of tumor-like lesions

This case belongs to the typical subperiosteal type.

Hemophilic pseudotumor should be differentiated from giant cell tumor of bone and bone cyst.