A rare case of high-grade chondroblastic osteosarcoma post-radiotherapy for a right frontal oligodendroglioma

This is the fourteenth case of an intracranial and dural-based osteosarcoma in the literature to date. The case involves a forty-year old woman with a previous history of a brain tumour, which was treated with surgery, chemotherapy and radiotherapy six years previously. The hypothesis is that this rare malignancy is secondary to the radiation exposure given the growth of the lesion in the previous radiation field

A case of recurrent chondroblastic osteosarcoma mandible

<p class="abstract">Osteosarcoma is an uncommon primary malignant tumor of bone. Craniofacial osteosarcomas constitute only about 6.5–7% of all osteosarcomas. The most common histopathologic type is chondroblastic type in head and neck group and osteoblastic in extremity group. We present a case report of 21 year old male patient with chondroblastic osteosarcoma with two episodes of recurrence. The tumour was dealt with left hemimandibulectomy followed by radiochemotherapy. After first recurrence he underwent right hemimandibulectomy. During second recurrence excision of growth followed by radiochemotherapy was done. Thus an aggressive multi-modality approach was adopted for treatment. Osteosarcoma is an uncommon primary malignant tumor of bone. Craniofacial Osteosarcomas are considered a separate category in view of their low histologic grade, less frequent metastases and better prognosis. The most common presentation is local swelling with or without pain. Aggressive surgical approach with post-surgical radiochemotherapy can be an effective tool.</p>

Bone mineral density changes in a free vascularised fibular graft in the distal femoral bone after osteosarcoma in a 10-year-old boy: a 7-year follow-up

A 10-year-old boy presented with continuous reports of pain located to the left knee. Imaging revealed a sclerotic process in the left distal femur, and biopsies were consistent with chondroblastic osteosarcoma. As part of standard treatment the patient underwent neoadjuvant chemotherapy followed by limb sparring surgery and adjuvant chemotherapy. The entire tumour was excised and femoral bone reconstruction was performed with a double barrel free vascularised fibular graft. Bone mineral density (BMD) can be decreased in childhood survivors of cancer. The patient was followed for 7 years with dual-energy X-ray absorptiometry scans in order to assess BMD and graft adaption. Despite two accidental fractures to the graft region local and global BMD underwent an overall increase. Approximately 7 years after tumour resection the patient had a global Z-score of 0.2, which is considered within normal range.

Osteosarcoma arising in a case of osteofibrous dysplasia of tibia with classic adamantinoma: A case report and literature review

A five-year-old boy presented with left tibial swelling; there was a typical radiological feature of osteofibrous dysplasia. He was observed until the age of 14 years; there was development of aggressive radiological features. Biopsy revealed chondroblastic osteosarcoma. It was excised and the histology revealed chondroblastic osteosarcoma. A small lesion distal to the main tumour revealed adamantinoma within a background of feature of osteofibrous dysplasia. Proximally, feature of osteofibrous dysplasia was identified focally. The finding of adamantinoma over the distal part of the lesion supports that feature of osteofibrous dysplasia may be a precursor of adamantinoma. They may be a spectrum of diseases with multistep neoplastic transformation. The osteosarcoma may be a result of de-differentiation from adamantinoma. This case is remarkable as the patient was only 14 years old and the tumour showed typical features of osteosarcoma, with feature of osteofibrous dysplasia and adamantinoma found in the same specimen. Feature of osteofibrous dysplasia may be a precursor of adamantinoma, and adamantinoma may dedifferentiate into osteosarcoma.

Novel RB1 and MET Gene Mutations in a Case with Bilateral Retinoblastoma Followed by Multiple Metastatic Osteosarcoma

Retinoblastoma (Rb) is a malignant tumor of the developing retina that affects children before the age of five years in association with inherited or early germline mutations of the RB1 gene. The genetic predisposition is also a driver for other primary malignancies, which have become the leading cause of death in retinoblastoma survivors. Other malignancies can occur as a consequence of radiotherapy. We describe a patient with retinoblastoma in which we detected a novel RB1 c.2548C > T, p.(Gln850Ter) and a synchronous MET c.3029C > T, p.(Thr1010Ile) mutation as well. After presenting with bilateral retinoblastoma, the patient developed at least four different manifestations of two independent osteosarcomas. Our goal was to identify all germline and somatic genetic alterations in available tissue samples from different time periods and to reconstruct their clonal relations using next generation sequencing (NGS). We also used structural and functional prediction of the mutant RB and MET proteins to find interactions between the defected proteins with potential causative role in the development of this unique form of retinoblastoma. Both histopathology and NGS findings supported the independent nature of a chondroblastic osteosarcoma of the irradiated facial bone followed by an osteoblastic sarcoma of the leg (tibia).

Intracardiac extension of chondroblastic osteosarcoma

Intravascular tumour extension invading the intracardiac space is rarely seen with osteosarcoma. We present a patient with a history of previously resected pelvic osteosarcoma who was later found to have a local recurrence with continuous intravascular extension from the right femoral vein to the right atrium. Preoperative imaging studies initially described extensive thrombus burden, and a multidisciplinary approach involving open and percutaneous thrombectomy was planned. Intraoperative inspection and pathological analysis revealed unresectable malignant solid tumour rather than thrombus. Though exceedingly rare, the possibility of metastatic tumour must be considered when planning treatment strategies for these patients.