Figure 1
Axial T1WI with fat suppression
A large mass with internal inhomogeneous signal intensity,due to blood products in various stages of organization.
Hemophilic pseudotumor
SectionMusculoskeletal system
Case TypeClinical Cases
AuthorsL.Dalamagkas, K.Iordanou, P.Sklavounos.
Connected authors
54 years, male
Clinical History
A 54 year old man with haemophilia A (FVIII=9%) presented with pain and a palpable mass in the right iliac fossa. The patient mentioned that the mass increased in size since last year and especially during last months.
Imaging Findings
On examination, a mass in the right iliac fossa was palpated.The mass was painful and increased in size since last year,although the patient mentioned that the first time he palpated it was approximately 2 years ago.There was a slight injury in this region,according to his sayings.A CT was performed.
The axial non-contrast CT demonstrates a large expansile lytic lesion with soft tissue attenuation and calcifications that involves the right iliac bone and extends into the pelvis (Fig 1). The next step was MRI. An axial T1WI (with fat suppression) of the pelvis shows a large mass with inhomogeneous signal intensity,due to existing blood products in various stages of organisation (methemoglobine with high signal in T1, fluid, and fibrosis). A low signal rim is demonstrated, because of hemosiderine deposition (Fig 2).
On axial contrast enhancement T1WI with fat suppression the lesion shows absence of enhancement.Moreover, one can see the iliac vessels displaced to the left, as a result of the mass extension (Fig 3). Therefore, a magnetic angiography was obtained, and showed in more detail the displacement of the right common, external and internal iliac artery to the left (Fig 4).
The axial non-contrast CT demonstrates a large expansile lytic lesion with soft tissue attenuation and calcifications that involves the right iliac bone and extends into the pelvis (Fig 1). The next step was MRI. An axial T1WI (with fat suppression) of the pelvis shows a large mass with inhomogeneous signal intensity,due to existing blood products in various stages of organisation (methemoglobine with high signal in T1, fluid, and fibrosis). A low signal rim is demonstrated, because of hemosiderine deposition (Fig 2).
On axial contrast enhancement T1WI with fat suppression the lesion shows absence of enhancement.Moreover, one can see the iliac vessels displaced to the left, as a result of the mass extension (Fig 3). Therefore, a magnetic angiography was obtained, and showed in more detail the displacement of the right common, external and internal iliac artery to the left (Fig 4).
Discussion
Haemophilic pseudotumours are uncommon, developing in 1-2% of patients affected with haemophilia. In most cases there is a prior history of trauma to the region. The pseudotumour represents a chronic, expanding haematoma with blood products in varying stages of organization, surrounded by a fibrous capsule.
The majority of the pseudotumours are contained within the soft tissues, most within muscles. There are also osseous pseudotumors, less common, developing within the medullary cavity or in a subperiosteal location.In most cases,the involved bones are the femur, pelvis (as in this case), tibia and hand bones.
Pseudotumours are radiographically variable. They are typically lytic, expansile lesions, may cause erosion of the adjacent bone(as in our case the right iliac bone), which may mimic a more aggressive lesion. MR imaging of the lesion demonstrates heterogeneous T1 and T2 signal due to blood products contained(showed in figures 2 and 3). MR is useful to delineate the extent of the lesion, as in this case with the displacement of iliac vessels.
Despite the variable imaging findings hemophilic pseudotumours may demonstrate, lesions with these characteristic findings in the clinical setting of a severe coagulopathy may be confidently diagnosed. The differential diagnosis includes many entities both benign (aneurysmal bone cyst, infectious processes, solitary bone cyst) and malignant (metastasis, osteosarcoma, malignant fibrous histiocytoma etc.).Therefore, clinical information is of great significance.
Treatment may vary from conservative (correction of coagulopathy) to aggressive (surgical excision), as in our case. Percutaneous biopsy or drainage is contraindicated due to complications, such as haemorrhage, infection or fistula formation.
The majority of the pseudotumours are contained within the soft tissues, most within muscles. There are also osseous pseudotumors, less common, developing within the medullary cavity or in a subperiosteal location.In most cases,the involved bones are the femur, pelvis (as in this case), tibia and hand bones.
Pseudotumours are radiographically variable. They are typically lytic, expansile lesions, may cause erosion of the adjacent bone(as in our case the right iliac bone), which may mimic a more aggressive lesion. MR imaging of the lesion demonstrates heterogeneous T1 and T2 signal due to blood products contained(showed in figures 2 and 3). MR is useful to delineate the extent of the lesion, as in this case with the displacement of iliac vessels.
Despite the variable imaging findings hemophilic pseudotumours may demonstrate, lesions with these characteristic findings in the clinical setting of a severe coagulopathy may be confidently diagnosed. The differential diagnosis includes many entities both benign (aneurysmal bone cyst, infectious processes, solitary bone cyst) and malignant (metastasis, osteosarcoma, malignant fibrous histiocytoma etc.).Therefore, clinical information is of great significance.
Treatment may vary from conservative (correction of coagulopathy) to aggressive (surgical excision), as in our case. Percutaneous biopsy or drainage is contraindicated due to complications, such as haemorrhage, infection or fistula formation.
Differential Diagnosis List
Hemophilic pseudotumor,treated with surgical excision
Final Diagnosis
Hemophilic pseudotumor,treated with surgical excision
References
[1] http://e-medicine.medscape.com/article/401842-imaging.
[2] http://www.learningradiology.com/notes/bonenotes/hemophiliapage.htm.
[3] Geyskens W, Vanhoenacker FM, Van der Zijden T, Peerlinck K (2004) MR imaging of intra-osseous hemophilic pseudotumor:case report and review of the literature. JBR-BTR 87:289-293. (PMID: 15679027)
[4] http://caseinpoint.acr.org.
Case information
| URL: | https://www.eurorad.org/case/7636 |
| DOI: | 10.1594/EURORAD/CASE.7636 |
| ISSN: | 1563-4086 |
Figure 2
Contrast enhanced T1WI with fat suppression
The right iliac vessels(small round areas of high signal intensity) are displaced to the left
Figure 3
Magnetic angiography
The right common,internal and external iliac arteries are displaced to the left
Figure 4
Axial Computed tomography
The CT shows a large expansile lytic lesion with soft tissue attenuation and calcifications that involves the right iliac bone
Axial T1WI with fat suppression
A large mass with internal inhomogeneous signal intensity,due to blood products in various stages of organization.
Contrast enhanced T1WI with fat suppression
The right iliac vessels(small round areas of high signal intensity) are displaced to the left
Magnetic angiography
The right common,internal and external iliac arteries are displaced to the left
Axial Computed tomography
The CT shows a large expansile lytic lesion with soft tissue attenuation and calcifications that involves the right iliac bone