Chondroblastoma patella presenting as a pathological fracture.

Area of Science:

• Orthopedic Oncology
• Musculoskeletal Pathology
• Bone Tumors

Background:

• Chondroblastoma is a rare, benign bone tumor typically found in the epiphysis of long bones.
• Patellar involvement by chondroblastoma is exceptionally rare, making diagnosis and management challenging.
• Pathological fractures secondary to bone tumors can present insidiously with minimal trauma.

Purpose of the Study:

• To report a rare case of chondroblastoma presenting as a pathological fracture of the patella.
• To highlight the diagnostic challenges and treatment of chondroblastoma at an unusual skeletal site.
• To emphasize the importance of considering rare tumors in the differential diagnosis of knee pathology.

Main Methods:

• Clinical presentation of a 24-year-old male with chronic knee pain and inability to walk after a fall.
• Radiographic evaluation revealing a transverse patellar fracture with a significant lytic lesion.
• Fine needle aspiration cytology (FNAC) and subsequent surgical patellectomy with histological analysis.

Main Results:

• Histopathology confirmed chondroblastoma, characterized by chondroid matrix, calcification, and focal areas of osteoclastic giant cells.
• The tumor occupied a substantial portion of the patella, leading to structural weakness and pathological fracture.
• FNAC findings were suggestive but not definitive, underscoring the role of surgical biopsy and histology.

Conclusions:

• Chondroblastoma, though rare, should be considered in the differential diagnosis of lytic lesions and pathological fractures of the patella.
• Early recognition and appropriate surgical management are crucial for favorable outcomes in such rare presentations.
• This case underscores the importance of comprehensive histopathological evaluation for accurate tumor diagnosis.