Osteoblastic and fibroblastic multicentric osteosarcoma

Primary fibroblastic osteosarcoma of sternum: A case report

RATIONALE

Osteosarcoma, a malignant bone tumor, rarely occurs in the sternum, especially the fibroblastic type, and is associated with poor survival. This case report describes a patient with a neoplasm of the sternum who underwent tumor resection 3 times and reconstruction twice because of the high risk of recurrence.

PATIENT CONCERNS

A 60-year-old Chinese man presented with a 3-cm palpable bulging mass located in front of his sternum. Chest computed tomography (CT) revealed an anterior chest wall neoplasm with sternal destruction.

DIAGNOSIS

Pathological examination revealed that the mass was a low-grade malignant primary fibroblastic osteosarcoma.

INTERVENTIONS

Locking plates were used for chest wall reconstruction, demonstrating good structural stability and economic applicability. Regarding the ineffectiveness of current therapies, whole-exome sequencing was conducted, and no targets matched any of the currently available agents.

OUTCOMES

No recurrence was found on regular reexamination.

LESSONS

Surgery is the first choice of treatment for patients with primary fibroblastic osteosarcoma of the sternum. The reconstruction-locking plate is a good alternative for chest wall reconstruction. Whole-exome sequencing can shed new light on this uncommon disease and help identify novel therapeutic targets.

Reconstruction using a frozen autograft for a skull and humeral lesion of synchronous multicentric osteosarcoma after undergoing successful neoadjuvant chemotherapy: a case report and review of the literature

Background

Synchronous multicentric osteosarcoma (SMOS) is a rare disease characterized by simultaneous multicentricity of intraosseous osteosarcoma without visceral involvement. SMOS, including a skull lesion, which occurs relatively rarely, and reconstruction using a frozen autograft after the excision of a lesion of SMOS has been infrequently reported previously.

Case presentation

We report an 18-year-old girl with SMOS, with lesions located in the left distal femur, right proximal humerus, and left occipital bone. Her major complaint was pain and swelling around the left knee joint. Asymptomatic lesions of the humerus and skull bone were detected on a systemic bone scan. No visceral organ metastasis was observed. A biopsy of the distal femoral lesion revealed osteosarcoma. Based on the histological findings, multiple bone lesions, and absence of visceral lesion, the clinical diagnosis of SMOS was made. After five courses of neoadjuvant chemotherapy with a regimen of doxorubicin and cisplatin, reconstruction using a tumor prosthesis following wide excision of the left distal femur was performed, and total necrosis was histologically observed in the retracted specimen. Following three cycles of adjuvant chemotherapy, tumor excision and reconstruction with a frozen autograft treated with liquid nitrogen was conducted for both lesions of the humerus and skull, rather than tumor prosthesis or synthetics, in order to retain a normal shoulder function, and to obtain a good cosmetic and functional outcome after treatment of the skull lesion. Further adjuvant chemotherapy could not be administered after the completion of the surgical treatment for all lesions because the adverse events due to chemotherapy were observed. At over 5 years after the diagnosis, she remains clinically disease-free.

Conclusions

An early correct diagnosis, the proper management of chemotherapy, and surgical treatment for all lesions are essential for achieving a good clinical outcome, even in SMOS including a skull lesion. By performing reconstruction using a frozen autograft for a proximal humeral lesion and a skull lesion after confirming the good histological efficacy of neoadjuvant chemotherapy for the primary lesion, the excellent function of the shoulder joint and a good cosmetic outcome at the site of the skull lesion was acquired without complications or recurrence.