Introduction: Aneurysmal bone cyst is a controversial osteolytic benign expansive lesions which occur more frequently in the metaphysis of long bones and spine. They are classified as primary or secondary lesions depending on the presence or absence of an associated bone pathology.
Case presentation: An uncommon case has proven histological of benign fibro-osseous lesions (fibrous dysplasia and juvenile psammomatoid ossifying fibroma) with secondary aneurysmal bone cyst formation inferior and lateral to the knee for a 7-year-old female patient. The lesion was surgically removed and the patient was followed up for 6 months with excellent results without any complications.
Discussion: There are many cases that have previously documented a bone aneurysm cyst, but what distinguishes this case is that it is a secondary type and its association with a benign bony fibrosis.
Conclusion: The combination of the two lesions constitutes a unique and rare case that can add to the medical literature within the orthopedic department.
Keywords: Aneurysmal bone cyst; Case report; Fibro-osseous lesions; Fibrous dysplasia.
© 2021 The Authors.