Primary aneurysmal bone cyst of the patella: a case report

Curettage through a wide cortical window for treatment of a primary aneurysmal bone cyst of the patella

A 27-year-old man presented with intermittent right knee pain for 1 year with no previous trauma. Physical examination revealed only tenderness over the patella. Typical fluid-fluid levels were visible on magnetic resonance imaging (MRI), which highly suggested aneurysmal bone cyst (ABC) of the patella. After removal of a large window of thin cortical bone, curettage and bone grafting followed by cerclage wiring was performed. Histology confirmed the initial diagnosis of primary ABC of the patella. At the final follow-up visit at 71 months after surgery, the patient had normal joint activity with no pain or evidence of recurrence. Previous publications indicated patellectomy in the initial series, but curettage and bone grafting have more recently provided excellent results and good graft incorporation in most cases, even for aggressive lesions. In our patient, thorough curettage and bone grafting through a wide cortical window followed by cerclage wiring fixation and figure-eight sutures was a successful treatment option for primary ABC of the patella without articular disruption.

Giant Cell Tumor with Secondary Aneurysmal Bone Cyst of the Patella: A Case Report

A 15-year-old girl presented with pain and swelling on the anterior aspect of the right knee for one year. The radiological evaluation with x-rays and magnetic resonance imaging suggested a benign aggressive lesion of the right patella with a cortical breach. Core needle biopsy of the lesion revealed it to be a giant cell tumor (GCT). She was treated with total patellectomy and end-to-end repair of quadriceps to the patellar tendon. The histopathological report of the whole specimen revealed it to be a GCT with secondary aneurysmal bone cyst (ABC). After 24 months, she was asymptomatic, and there was no evidence of local recurrence or distal metastasis. An extensive review of the literature revealed only four cases of combined GCT with secondary ABC in the patella. Though rare, GCT with secondary ABC of the patella should be kept as a differential diagnosis for anterior knee pain and swelling in young patients. The diagnosis is solely based on histopathological findings. It is imperative to obtain a precise tissue diagnosis in the preoperative period to plan appropriate treatment. 

Pathological fracture of the patella due to an atypical located aneurysmal bone cyst: verification by means of ultrasound-guided biopsy

INTRODUCTION

We report on a rare case of an atypical located aneurysmal bone cyst (ABC) in the patella presenting with pathological fracture after trauma.

MATERIALS AND METHODS

Using all available diagnostic modalities and by means of ultrasound-guided core-needle biopsy an unclear and suspected pathological fractured cystic bone lesion in the patella of a young man could be further clarified.

RESULTS

The acquired images suggested the diagnosis of a pathological fractured aneurysmal bone cyst after mild trauma. However, due to the extraordinary location and clinical presentation the diagnosis was secured by means of ultrasound-guided biopsy through a small cortical gap.

CONCLUSION

As shown in this rare case of an atypical aneurysmal bone cyst of the patella, the quite seldom but sometimes possible ultrasound-guided biopsy of intraosseous lesions can help to achieve the diagnostic clarification and should also be taken into account as a non-standard procedure.

Aneurysmal bone cyst secondary to a giant cell tumor of the patella: A case report

The patella is an unusual location for primary and metastatic bone tumors to develop. The most frequently encountered primary osteolytic lesions at the patella include giant cell tumors of the bone (GCT), chondroblastoma and aneurysmal bone cysts (ABC). However, the presentation of an ABC originating secondary to a GCT at the patella is rare. The present study describes such a case in a 46-year-old female. The differential diagnosis of the condition was extensive. The patient underwent curettage and the addition of bone cement to fill the defect. Pathological analysis of the resected tissue demonstrated that the lesion was consistent with an ABC forming secondary to a GCT. A 3-month follow-up was completed subsequent to the surgery, with a computed tomography scan demonstrating no evidence of recurrence. However, frequent and continuous observations of the patient following diagnosis are planned in order to evaluate the long-term efficacy of the surgical treatment. To the best of our knowledge, the present study describes the third reported case in the literature of this rare, double synchronous, benign tumor located at the patella.

Challenges in imaging and histopathological assessment of a giant cell tumour with secondary aneurysmal cyst in the patella

The patella is an uncommon site for all primary and metastatic bone tumours and primary intra-osseous tumours of the patella are very rare. A majority of the patella tumours are benign. We report a patient with a sudden onset swelling and pain of the right knee following a staircase fall. The plain radiograph showed an expansile multiseptated patella lesion and it was further assessed with an MRI. The radiological findings and the initial histopathological features from a limited sample were suggestive of a primary aneurysmal bone cyst. However, the final histopathological diagnosis from a more adequate specimen was a giant cell tumour with a secondary aneurysmal bone cyst.

Primary aneurysmal bone cyst of the patella: a case report

An aneurysmal bone cyst is rare in the patella. We report the case of a 28-year-old woman who presented with chronic pain and no previous trauma history. Treatment included curettage of the cyst and filling with a corticocancellous graft. Thirty-one months after surgery, the knee was mobile and painless and graft incorporation was good.

Uncommon cause for anterior knee pain - Aggressive aneurysmal bone cyst of the patella

A 56-year-old man presented with a two month history of increasing anterior knee pain without previous trauma. As usual we recommended physiotherapy with stretching exercises of the quadriceps muscle. Since symptoms did not improve after 6 weeks MRI was performed. Surprisingly a hyperintense lobulated mass of the patella with small fluid-filled cavities at the inferior pole was revealed. We performed an open biopsy to exclude any malignancy and diagnosed an aneurysmal bone cyst. Further examination with CT scans showed an aggressive behaviour with cortical breakthrough.

We performed an intralesional curettage with additional high-speed burring and bone cement packing. Sixteen months later the patient was free from any complaints and without signs of local recurrence.

Primary bone tumors of the patella are extremely rare and occurrence of aneurysmal bone cysts in this localization is very uncommon. This case report indicates that although anterior knee pain is a very frequent and usually harmless symptom, it is essential to consider that it might also be caused by more severe disorders such as bone tumors.