Pedunculated femoral bone tumor is a type of osteochondroma or exostosis usually found at the distal end of the femur bone. The bony projection is almost always benign, and is referred to as pedunculated if it has a stalk. Most osteochondromas are asymptomatic and are often only diagnosed incidentally, and as such treatment is usually not considered necessary.
The tumor occurs due to the herniation of a portion of the growth plate. It generally develops during the first 20 years of life when the long bones are developing and growing. The distal femur is the most common site for development of osteochondroma, accounting for around 25 percent of all cases.
Symptoms of pedunculated femoral bone tumor
Many osteochondromas present as painless masses with no further symptoms, but sometimes pain and other symptoms may result from the mechanical irritation of surrounding blood vessels, nerves, tendons or ligaments.
Femoral bone tumors have been reported to cause vascular problems ranging from the occlusion of the femoral artery to pseudoaneurysm of the popliteal artery. Some osteochondromas are associated with neurological symptoms, but femoral tumors rarely cause neurological complications. Occasionally the stalk of the tumor may suffer a fracture, but this is rare and occurs due to localised trauma.
Malignant transformation and development of chondrosarcoma occurs in around 1 percent of lesions, and the average age for malignant transformation to occur is 50 to 55. Malignant transformation is usually accompanied by growth of the tumor in adults or development of pain.
Diagnosis of pedunculated femoral bone tumor
Pedunculated femoral bone tumor can be diagnosed using a simple x-ray, but CT scans or MRI may also be indicated in order to eliminate any possible complications. CT scans and MRI can identify occlusion of blood vessels or interference of the tumor with other soft tissue structures such as tendons and ligaments. MRI scans can also indicate the likelihood that the tumor has become malignant.
X-ray of pedunculated femoral bone tumor
Treatment and prognosis
If there are no associated symptoms treatment may not be necessary, but occasionally the tumor may need to be removed by surgical excision. A long-term follow-up study of osteochondroma patients was undertaken by Florez et al. Six of the 113 patients studied had a recurrence, and two patients developed malignant chondrosarcoma. In cases where the tumor was surgically removed, an estimated 2 percent of patients suffered a relapse.
 ID Dickey “Solitary Osteochondroma” emedicine from WebMD (2009)
 “Osteochondroma” bonetumor.org
 AB Smits, HDWM vd Pavoordt, FL Moll “Unusual Arterial Complications Caused by an Osteochondroma of the Femur or Tibia in Young Patients” Annals of Vascular Surgery 12:37-372 (1998)
 MD Murphey, JJ Choi, MJ Kransdorf “Imaging of Osteochondroma: Variants and Complications with Radiologic-Pathologic Correlation” Radiographics 20:1407-1434 (2000)
 B Florez, J Monckeberg, G Castillo, J Beguiristian “Solitary Osteochondroma Long-Term Follow-Up” Journal of Pediatric Orthopaedics 17:91-94 (2008)
Image courtesy of Lucien Monfils (Wikimedia Commons)