The imaging characteristics of hemophilic pseudotumor

Abstract

Objective To investigate the imaging characteristics of hemophilic pseudotumor. Methods Twelve cases of type A hemophilic pseudotumor proved by clinic and laboratory examination were included in the study. The X-ray, CT and MRI examination were performed in 6, 9 and 5 cases, respectively. The imaging appearances of 12 cases were retrospectively analyzed regarding the pseudo-tumor location, size, density, bone destruction, enhancement and the change of adjacent tissue. Results In 12 cases of hemophilic pseudo-tumors, there were 4 cases in femur, 3 cases in ilium, 3 cases in skull and 2 cases in calcaneus. There were intra-muscular type (n=1), subperiosteal type (n=2) and intra-osteal type (n=9).The size of pseudo-tumor was 5.0-60.0 cm, mean (19.1±6.0) cm, and more than 10.0 cm in 7 cases. X-ray and CT demonstrated expansive bone destruction(n=6), expansive and lytic bone destruction(n=3), erosive bone destruction(n=2), cystic and lytic bone destruction(n=1); bone destruction with edge sclerosis(n=10), thick bone crest residue within bone destruction(n=2), bone destruction with pathologic fracture(n=2), pseudo Codman's triangle(n=1), and soft tissue mass(n=10) with higher density (CT value 45-68 HU) than normal muscle. CT showed no enhancement in bone destruction and soft tissue mass in 5 cases of contrast agent enhancement and CT angiography demonstrated compression and displacement of pseudo-tumor and adjacent vessels. MRI examination (n=5) showed soft tissue masses and bone destruction with high, low and mixed signals on T2WI, T1WI, SPAIR and DWI sequences, as well as multiple cystic and separate change in pseudo-tumors(n=2, respectively). Conclusions Hemophilic pseudo-tumor has some imaging characteristics, such as expansive, cystic and erosive bone destruction, thinning or disappearance of bone cortex, bone destruction with edge sclerosis, prominent soft tissue mass, mixed density or signal on CT or MRI, and no contrast enhancement, et al. It can be clearly diagnosed on imaging together with clinic andlaboratory information. Key words: Tomography, X-Ray computed; Magnetic resonance imaging; Hemophilia pseudotumor