Extraosseous Osteogenic Sarcoma

Introduction

Extraosseous osteogenic sarcoma is a sporadic kind of malignancy. Only 1.2 % of all soft tissue sarcomas are of this kind. The first instance of this sarcoma was reported in 1941, and less than 200 occurrences have been recorded. Osteogenic sarcoma of bone is the most common kind of variant. They develop in children and adolescents, middle-aged and elderly persons. People with extraosseous osteogenic sarcomas are often older than 40 or children or adolescents.

What Is Extraosseous Osteogenic Sarcoma?

Extraosseous osteogenic sarcoma is a rare kind of bone cancer. The appearance of osteogenic sarcoma outside of the skeletal system is highly unusual. However, extraskeletal bone growth is not affected by several stimuli. Osteogenic sarcoma can arise in soft tissues, most commonly in the proximal lower limbs. The rare location for it to occur is the mediastinum. Given the aggressive nature of extraosseous osteogenic sarcoma, total surgical resection with adjuvant chemotherapy and radiation, including preoperative neoadjuvant chemotherapy, is the treatment of choice. Extraskeletal osteosarcoma is an uncommon kind of soft tissue sarcoma that accounts for less than two percent of all soft tissue sarcomas. Middle-aged and elderly patients, a history of radiation, and questionable relation to trauma are all known risk factors for development.

What Is the Incidence and the Site of Origin For Extraosseous Osteogenic Sarcoma?

Malignancy is uncommon in all age categories, accounting for less than one percent of all soft tissue sarcomas, and skeletal osteosarcomas, which typically occur in the first two decades of life, account for less than five percent of all osteosarcomas. Extraosseous osteogenic sarcoma typically affects those above 20 but can also occur in younger children. The tumor usually develops in the upper region of the leg or thigh. Other tumor locations included the retroperitoneum and the pilonidal region.

What Are the Signs and Symptoms of Extraosseous Osteogenic Sarcoma?

The most prevalent presentation is gradual swelling with accompanying discomfort. Before the patient seeks medical attention, the tumor frequently swells to a great size. The soft tissues of the limbs (67 %) and the retroperitoneum (17 %) appear to be the most often afflicted areas in adults. Although limb primary tumors have been recorded in young children, a retroperitoneal tumor has never been described.

How Is Extraosseous Osteogenic Sarcoma Diagnosed?

Physical Evaluation -

• These tumors are typically encased in a solid connective tissue capsule tightly adhered to surrounding tissues, making dissection exceedingly tricky.

• Occasional ulceration of the overlying skin tumors ranges from 1.5 cm to 20 cm in maximum diameter.

• The color of the tumor cut surfaces ranges from red to grey, greyish white, whitish grey, or yellowish-white; numerous combinations can be found in different sections of the same tumor.

• Hemorrhagic and necrotic areas are shared.

• The core region is normally cystic, but the perimeter is solid with occasional flecks of calcification or bone growth.

Radiographic Evaluation -

• A radiographic evaluation of the soft tissue is required to rule out tumor-bone continuity. If a nearby bone displays radiologic alterations indicating tumor involvement, it is most likely a bone sarcoma rather than a soft tissue.

• One of the characteristic radiographic presentations of this tumor is a soft tissue mass with patchy calcification and no surrounding bone involvement.

• The presence of malignant osteoid is the most crucial requirement for diagnosing this malignancy.

Histologic Evaluation -

• Fibroblastic and chondroblastic components may be in varying amounts.

• The tumor's nodular pattern is a prominent histopathological characteristic.

• The nodules are highly cellular and include both spindle and giant cells, typically organized in cords, as in fibrosarcoma.

• Spindle cell nuclei vary in form, size, and staining quality and are typically hyperchromatic.

What Is the Differential Diagnosis for Extraosseous Osteogenic Sarcoma?

To differentiate between different tumors, specific histologic identification should be performed only after extensive neoplasm sampling.

1. Malignant giant cell tumor.

2. Malignant fibrous histiocytoma of soft tissue (type of soft tissue cancer).

3. Myositis ossificans (bone formation inside muscles).

What Is the Treatment of Extraosseous Osteogenic Sarcoma?

Given the aggressive nature of these outcomes, total surgical resection with adjuvant chemotherapy and radiation, maybe with the inclusion of preoperative neoadjuvant chemotherapy, is the treatment of choice.

Surgery -

• The treatment of choice should be wide local excision with at least a five centimeters margin of normal tissue. Amputation may be considered if this is impossible due to the tumor's anatomic placement.

• Because of the high recurrence rate of extraosseous osteogenic sarcoma following resection, simple excision or enucleation of the tumor should be avoided.

• During a thorough inspection of the tumor, the tumor has an extraordinary capacity to infiltrate the surrounding muscles, tendons, and adipose tissue.

• The lesion may touch the periosteum of the underlying long bone in rare cases.

Adjuvant Chemotherapy and Radiation -

• It may be beneficial since recurrence occurs most frequently within two years following treatment. Careful preoperative assessment and multimodal therapy are necessary for treating individuals with extraosseous osteogenic sarcoma.

• Thus, careful preoperative assessment and multimodal therapy are necessary for treating individuals with extraosseous osteogenic sarcoma.

What Is the Prognosis of an Extraosseous Osteogenic Sarcoma?

Most of these tumors progress aggressively, with frequent local recurrence following resection and early metastasis, most often to the lung. In a study of 48 patients at Memorial Sloan-Kettering Cancer Center, the median duration of metastasis recurrence was just seven months. Local recurrence occurred in 70 % of all patients, and distant metastases occurred in 80 %, with most recurrences becoming apparent within two years. The average survival time was 31 months. Other studies report five-year survival rates ranging from 13 % to 22 %. Thus preoperative neoadjuvant treatment may help treat this tumor. However, chemotherapy has a low response rate in patients with distant metastases.

Conclusion:

Adult extraosseous sarcoma appears to have an aggressive clinical history, with 70 % having a local recurrence and 80 % acquiring metastatic disease within two years following the first tumor removal. It can appear in soft tissues, most often in the proximal lower limbs. Given the aggressive nature of these results, complete surgical resection with adjuvant chemotherapy and radiation, maybe with preoperative neoadjuvant chemotherapy, is the treatment of choice. Thus, rigorous preoperative screening and multimodal treatment are required when treating patients with extraosseous osteogenic sarcoma.