Multifocal osteosarcoma in childhood

Advance MR evaluation of synchronous multifocal osteosarcoma with pathologic fracture

Objective:

Synchronous multifocal osteosarcoma is a rare condition in which the osteosarcoma presents with multiple bone lesions at the time of diagnosis, usually without any visceral metastases. The first case was described in early 1930s by Silverman. To report a case of synchronous multifocal osteosarcoma in adolescent with pathologic fracture.

Methods:

An 18-year-old girl presented with a painful mass in the right thigh of 4 months’ duration and a history of thigh bone fracture a month ago. Patient’s medical records and family history was unremarkable. Physical examination showed angulation and shortening at right femoral region with tenderness and swelling. Initial radiograph and magnetic resonance (MR) images showed multiple lesions in right femoral shaft and pelvic bone with primary tumor in right distal femur with pathologic fracture and multiple bone marrow lesions found in the contralateral bones. Imaging and histopathological results supported the diagnosis of synchronous multifocal osteosarcoma. After following the chemotherapy as the treatment of choice, the radiograph and MRI evaluation were done and showed reduction of the mass size with union of the destructed part with the formation of callus. The advance MRI revealed reduction of the overall mass and the composition of the viable area compared to previous study. The patient had satisfying response to chemotherapy series and a better functional outcome on subsequent visits.

Results:

Diagnosis of synchronous multifocal osteosarcoma was based on patient and family history and finding of multiple lesions in the MR images, meanwhile the plain radiograph only revealed the primary tumor. Amstutz described multifocal osteosarcoma as presence of one primary tumor and several smaller lesions. Most recent reviews concluded that multifocal osteosarcoma is bone-to-bone metastatic process rather than multicentric origin. The limitation in this case was absence of thoracic CT which is suggested to rule out any pulmonary metastases instead of routine chest radiograph.

Conclusion:

Although satisfying improvement was clinically achieved, further advanced MRI would be indicated to evaluate the progression of tumor and its respond to therapy.

Multifocal bone and bone marrow lesions in children - MRI findings

Polyostotic bone and bone marrow lesions in children may be due to various disorders. Radiographically, lytic lesions may become apparent after loss of more than 50% of the bone mineral content. Scintigraphy requires osteoblastic activity and is not specific. MRI may significantly contribute to the correct diagnosis and management. Accurate interpretation of MRI examinations requires understanding of the normal conversion pattern of bone marrow in childhood and of the appearances of red marrow rests and hyperplasia. Differential diagnosis is wide: Malignancies include metastases, multifocal primary sarcomas and hematological diseases. Benign entities include benign tumors and tumor-like lesions, histiocytosis, infectious and inflammatory diseases, multiple stress fractures/reactions and bone infarcts/ischemia.

Preliminary Application of Precision Genomic Medicine Detecting Gene Variation in Patients with Multifocal Osteosarcoma

OBJECTIVES

The purpose of this study was to present our clinical experience of treating multifocal osteosarcoma (MFOS) in our center and gain more insight into the biology of this rare condition; in particular, to address with the help of precision genomic medicine the issue of whether the multiple osteosarcoma (OS) lesions in such patients are multi-centric or originate from one primary lesion and metastasize to other sites. Finally, we aimed to identify particular gene phenotypes and mutations that differentiate MFOS from OS with only one tumor.

METHODS

Clinical data of patients with MFOS treated at our center between June 2007 and October 2014 were collected and analyzed retrospectively. High throughput sequencing of the whole exome of normal tissue and multiple lesions had been performed on samples from two patients (HJF and JZ) diagnosed in 2014. To explore the particular gene phenotype and clinical significance of MFOS, these sequencing results were analyzed and compared with those from patients with osteosarcoma in a single site. Seven patients with MFOS (three male and four female; average age 19.71 ± 3.35 years were enrolled in this study. Two of these patients declined treatment and died after 4 and 6 months, respectively. The remaining patients received standard treatment comprising neoadjuvant chemotherapy, surgery and chemotherapy. The chemotherapy regimen was lobaplatin (45 mg/m(2) ), doxorubicin (60 mg/m(2) ) and ifosfamide (12 g/m(2) ). Patients were followed up every 3 months after completing treatment and evaluated by the Enneking and Response Evaluation Criteria in Solid Tumors scoring systems.

RESULTS

Up to the last follow-up on 1 December 2015, three patients were still alive. The event-free survival ranged from 4 to 144 weeks (median, 50.14 weeks), the mean (±SD) being 55.45 ± 45.47 weeks. Overall survival ranged from 16 to 388 weeks (median, 89 weeks; mean ± SD, 118.7 ± 147.7 weeks). The rates of mutation of the targeted drug-related genes were 133.5% ± 3.0% in the proximal tibia lesion and 113.1% ± 1.9% in the distal femur of patient HJF (P < 0.01) and 136.1% ± 10.8% in the proximal tibial lesion and 122.3% ± 5.5% in the proximal humerus of patient JZ (P = 0.0335). Furthermore, there were several anti-oncogenes in the somatic copy number variation lists analyzed from the two patients, especially TP53. However, no kataegis was found.

CONCLUSIONS

Early and radical surgery accompanied by appropriate chemotherapy is the optimal means of treating MFOS. These patients may benefit from precision genomic medicine.