Chondroblastoma

Original Editors -Drew CecilChancelor Chadwick  ;from Bellarmine University's Pathophysiology of Complex Patient Problems project. Top Contributors - Drew Cecil, Chancelor Chadwick, Rewan Elsayed Elkanafany, Elaine Lonnemann, Admin, Nikhil Benhur Abburi, Vidya Acharya, 127.0.0.1, Wendy Walker, Evan Thomas, WikiSysop and Kim Jackson  

Definition/Description

Chondroblastoma, also referred to as Codman tumours are a benign bony tumour that is caused by the rapid division of chondroblast cells which are found in the epiphysis of long bones. They have been described as calcified chondromatous giant cell tumours. The most frequently involved body regions are the hip, knee, and shoulder. Although usually benign, chondroblastoma metastasizes on rare occasions, with fatal results.

Prevalence

Chondroblastoma is a relatively rare, benign cartilaginous tumour, accounting for approximately 1% of the benign tumours of bone. The peak incidence is in the second decade of life and is slightly more common in males than females. In addition to long bones, chondroblastoma also occurs in the acetabular region of the pelvis, scapula, spine, and ribs. It can also occur in the patella, tarsal bones, and occasionally in craniofacial bones.

Metaphyseal origin is rare but has been reported. Rare cases of multifocal chondroblastoma with synchronous involvement of several typical sites have also been documented. A small number of cases have reported chondroblastomas that are exclusively found in soft tissue.

Recurrence of the tumour happens in about 20% of cases, and seems to depend on the location of the initial tumour and the surgical intervention selected to treat it. Recurrence is most common in tumours of the hip and lumbar spine.

Characteristics/Clinical Presentation

Clinically, patients present with the following signs and symptoms in the early stages of tumour development:

• Pain
• Muscle wasting
• Swelling around the joint
• Limited range of motion secondary to pain
• Palpable mass at the sight of the lesion
• Antalgic gait patterns secondary to pain and decreased range of motion.

In later stages of tumour development the following signs and symptoms may become evident:

• Synovitis
• Joint effusion
• Periostitis

Histologically, the tumour is built up of round or polygonal chondroblasts surrounded by reticulin fibers. The matrix is pink stained chondroid, with occasional focal calcification. Scattered osteoclast-type multi-nucleated cells are often present. Dystrophic (chicken-wire) calcification is occasionally present but is not necessary for diagnosis.

The following is a link to a video which discusses the histological components of a chondroblastoma:

Associated Co-morbidities

No associated co-morbidities were found to be related to condroblastoma.

Medications

There is currently no evidence that supports the pharmacological management of chondroblastoma. Over the counter medications such as nonsteroidal anti-inflammatory drugs (Ibuprofen) and acetaminophen (Tylenol) are commonly used for the management of pain as needed.

Diagnostic Tests/Lab Tests/Lab Values

Biopsy

In cases that appear to be atypical upon imaging, a needle or incisional biopsy of the tumour may be required before further surgical intervention can take place.

Radiographic Imaging

The appearance of chondroblastomas in radiographic imaging is reflected by the benign, slow-growing nature with well defined lucent lesions. They are usually revealed as round or oval, lucent lesions with sharply marginated borders. Radiographs may also be useful in differentiating chondroblastoma from other benign bony tumours when periostitis is present

Magnetic Resonance Imaging

MRI can be useful in depicting the extent of the tumour when a chondroblastoma extends to the metaphysis of long bones. The stroma of the bony tumour provides a low signal intensity on T1-weighted( low to intermediate signal) images and variable signal intensity on T2-weighted(T2- intermediate to high signal) images. The signal intensities of other bony tumours ( endochondromas, osteochondromas, etc.) tend to be very high in T2 weighted images, a characteristic that is not seen in chondroblastomas. In some cases, MRI and radiographic images may have contradicting results. In this situation, the diagnosis of chondroblastoma should be made based off of radiographic images.

Nuclear Imaging

Nuclear imaging involves the uptake of a radionuclide agent that is absorbed by the bone. This type of imaging has proven to be useful as the agent is absorbed by the highly vascularized area surrounding the tumour. Nuclear imaging is not typically used to diagnose chondroblastoma, rather, it can be used to rule in other bony tumours that are typically multifocal in nature such as endochondromas and osteochondromas.

Angiography

Angiography is not typically used as a diagnostic intervention, however, it can be useful in planning for surgical removal of the tumour. Angiograms rarely reveal any serious vascular abnormality, but there have been reports of vascular displacement in cases where large tumours are present. Periosteal reactions and neovascularization of nearby cortical bone have been reported in some angiographic imaging cases.

Computed Tomography

CT scanning is rarely used as a diagnostic tool in patients with chondroblastoma. This imaging modality is usually reserved for more severe or recurrent tumours. CT scans can depict matrix mineralization, an extension of the tumour into the soft tissue, and erosion of cortical bone. Coronal and sagittal reconstructions can be used to assess the extension of the tumour across the epiphyseal plate into the metaphysis of the bone. Solid periosteal reaction and Endoosteal scalloping may be seen.

The following is a link to a video which depicts CT scan results of a chondroblastoma in the proximal tibia:

Etiology/Causes

Chondroblastomas occur when a single chondroblast cell begins to divide at an abnormally high rate. This typically occurs in the epiphyseal region of long bones. The cause of the high rate of cell division is unknown. There is currently no evidence that links chondroblastoma to a faulty or abnormal gene. Chondroblastoma has also been found to have no association with repeated joint trauma.

Systemic Involvement

Musculoskeletal

• Joint pain
• Decreased range of motion
• Atrophy of muscle
• Pathological fracture

Integumentary

• Elevated temperature of the overlying skin
• Swelling at the location of the tumour

Neurologic

• Bowel and bladder dysfunction
• Sexual dysfunction
• Numbness/weakness in lower extremity

Cardiopulmonary

• Possibility of metastasizing to lungs

Medical Management (Current Best Evidence)

Most patients undergo curettage and bone grafting surgery when the tumour is present, high speed burring can also be included in the surgery. Other treatments vary in the type of replacement after the curettage. These types of fillings can include polymethylmethacrylate and fat implantation. Long term follow-up is needed because of the tumours ability for late recurrence.

Radiofrequency ablation is also used to treat this type of tumour. According to the Mayo Clinic, radiofrequency ablation is a treatment in which the doctor inserts a thin needle through the skin and into the tumour, guided by imaging techniques. High-frequency electrical energy delivered through this needle heats and destroys the tumour. Months after the procedure, dead cells turn into a harmless scar.

Physical Therapy Management (Current Best Evidence)

Although physical therapy does not have a direct role on the treatment of chondroblastoma, it does have an important role in maintaining the well-being of the patient. Physical therapists have the ability to screen for non- musculoskeletal involvement by recognizing red-flags that may be associated with chondroblastoma. The Therapist can refer patients to the proper healthcare provider if such a discovery is made.

Physical therapy will be involved in treating any impairments, functional limitations, or disabilities that can occur secondary to chondroblastoma. Increasing the patient’s quality of life and allowing the patient to maintain an independent lifestyle are the main goals of physical therapy for patients. The treatment will focus on improving mobility, allowing the patient to return to their prior level of function, and reducing pain. Cardiovascular fitness will also be an important aspect of treatment. Improving this will help the patient’s energy levels and tolerance for activities of daily living.

Differential Diagnosis

Differential diagnosis is important for both the physician and the physical therapist. The physician must differentiate between different bony tumor disease processes using appropriate imaging and histological findings. The physical therapist, especially in a direct access situation, must be able to rule out articular or soft tissue injuries in order to refer the patient to the proper practitioner. Below, is a list of possible differential diagnoses seen with chondroblastoma:

• 
  Giant cell tumour
• Chondrosarcoma
• Endochondroma
• Osteochondroma
• Osteoarthritis
• Rheumatoid Arthritis
• Juvenile Rheumatoid Arthritis
• Periarticular Soft Tissue Injury
  

Case Reports/ Case Studies

Title

Chondroblastoma Of A Metacarpal Bone Mimicking an Aneurysmal Bone Cyst: A Case Report And Review Of The Literature

Authors

Takuya Kudo, Kyoji Okada, Yoshinori Hirano, and Masato Sageshima

Abstract

Chondroblastoma of the metacarpal bone is rare. This study talks about a case where a 21-year-old male developed a chondroblastoma of the first metacarpal bone on the right hand. Radiographs showed an expansile osteolytic lesion with a multilocular appearance. In the MRI the lesion showed low-intensity in T1 and high intensity in T2-weighted images with multiple fluid levels. These MRI findings resemble an aneurismal bone cyst (ABC). The tumour was recognized as a chondroblastoma from the pathological findings. 

Examination

The 21-year-old male had experienced swelling of his right thenar region. The physical examination revealed swelling tenderness and a well-defined tumour with bony hard consistence in the right thenar region of the right hand. Excursion of the metacarpophalangeal joint and carpometacarpal joint was limited. The patient did not have any history of trauma and laboratory data was unremarkable.
Radiographs showed thinning and ballooning of the bone cortex of the entire right first metacarpal bone, except in its distal end. In the medullary region of the metacarpal bone, and osteolytic lesion having multilocular septa was found. Sclerotic change of the rim of the lesion was prominent in the radial distal site.

Summary of findings

A benign bone tumour such as ABC or giant cell tumour with ABC-like change was suspected. Histologically, low power magnification showed a number of large and small cystic spaces filled with blood, suggesting and ABC. Based on the presence of pink-stained chondroid foci and a coffee-bean appearance of the nuclei of the cells, chondroblastoma with ABC-like change of the first metacarpal bone was diagnosed.

Intervention

Complete resection of the tumour was performed, leaving only the distal end of the metacarpal bone. A columnar shaped iliac bone was used to replace the bony tumour that was resected and fixed through the carpometacarpal joint.

Outcome

The patient was followed up with until the 27th-month post-op, there was no sign of local recurrence in a physical and radiological examination, and the bone union was in satisfactory condition.

Discussion

In summary, this is a rare case of chondroblastoma. In the imaging diagnosis, it appeared to be an ABC or giant cell tumour with ABC-like change. The resection and subsequent bone graft provided a good clinical outcome. The authors stressed that chondroblastoma rarely occurs in metacarpal bone, and may show imaging features similar to those of ABC.