extraosseous osteosarcoma

What is Extraosseous Osteosarcoma?

Extraosseous osteosarcoma (EOO) is a rare and aggressive type of cancer that originates from soft tissue, rather than bone. It is characterized by the production of osteoid or cartilaginous matrix, which are abnormal bone-like tissues.

Key Features:

• Rare occurrence: EOO accounts for approximately 1% of all soft-tissue sarcomas and 4% of osteogenic osteosarcomas.
• Soft tissue origin: Unlike conventional osteosarcoma, which arises from bone, EOO develops in soft tissue without skeletal attachment.
• Aggressive behavior: EOO is a chemoresistant tumor with a poor prognosis, often recurring after treatment and spreading to other parts of the body, including the lungs.

Demographics:

• Age: EOO usually occurs in middle-aged or older adults, with a median age at diagnosis similar to soft tissue sarcoma.
• Sex: The majority of patients are male (60%), while 40% are female.

Clinical Presentation:

• Soft-tissue mass: Patients most commonly present with an enlarging soft-tissue mass either with or without pain.
• Location: EOO can occur in various locations, including the retroperitoneum and soft tissue of extremities.

Prognosis:

• Poor prognosis: Due to its aggressive nature and resistance to chemotherapy, EOO has a poor prognosis compared to conventional osteosarcoma.
• Recurrence: EOO often recurs after treatment, making it challenging to manage.

References:

[1] A rare, fast-growing type of cancer that is made up of bone and cartilage cells, and forms in soft tissue near bones. It usually occurs in the thigh, buttock, or other areas of the body. [2] Extraosseous osteosarcoma (EOO) is a rare sarcoma with clinicopathologic features that are distinctively different from conventional osteosarcoma of bone. [3] The median age at diagnosis of our cohort is similar to soft tissue sarcoma and previously reported series of EO, 12–14 in stark contrast to osseous osteosarcoma, which commonly presents within the first 2 decades of life.

Common Signs and Symptoms of Extraosseous Osteosarcoma

Extraosseous osteosarcoma, a rare type of bone cancer, can manifest in various ways depending on its location. Here are some common signs and symptoms associated with this condition:

• Abdominal pain and mass: Intra-abdominal extraosseous osteosarcoma often presents with abdominal pain and a palpable mass [9].
• Pain and swelling near the tumor site: Pain at the site of the tumor in the bone is the most common symptom of osteosarcoma, including extraosseous types [10].
• Bone or joint pain: Osteosarcomas can cause bone or joint pain, which might initially come and go but gradually become more severe and constant [7].
• Swelling near the affected area: Swelling near the tumor site is another common symptom of osteosarcoma, including extraosseous types [11].
• Lump under the skin: A progressively enlarging mass under the skin, which rarely shows pain and tenderness, is a common symptom of osteosarcoma [4].

Rare Locations and Symptoms

Extraosseous osteosarcoma can arise from various sites, including:

• Retroperitoneum
• Muscles of thighs or limb girdles
• Lung
• Prostate
• Scalp
• Mammary gland
• Spermatic cord
• Pelvis
• Orbit

In these rare locations, the symptoms may vary depending on the specific site affected. For example, in the lung, it may present with respiratory symptoms [15].

Important Note

It's essential to note that extraosseous osteosarcoma is a rare and aggressive type of cancer, and its symptoms can be non-specific, making diagnosis challenging. If you suspect any of these symptoms, consult a medical professional for proper evaluation and treatment.

References:

[4] Jun 16, 2020 — Signs and Symptoms [7] Oct 9, 2024 — Pain in the affected bone is the most common symptom. [9] by T Wang · 2020 · Cited by 5 — Intra-abdominal extraosseous osteosarcoma is rare. Abdominal pain and abdominal mass are common clinical manifestations, but the early symptoms ... [10] Osteosarcomas are usually found because of the symptoms they are causing. [11] Symptoms. Bone or joint pain. Pain might come and go at first. It can be mistaken for growing pains. Pain related to a bone that breaks for no clear reason. Swelling near ... [15] It often recurs (comes back) after treatment and spreads to other parts of the body, including the lungs. Extraosseous osteosarcoma usually occurs in middle-aged or older adults, and is rare in children and adolescents.

Diagnostic Tests for Extraosseous Osteosarcoma

Extraosseous osteosarcoma, a rare and aggressive form of bone cancer, can be challenging to diagnose. However, various diagnostic tests can help identify this condition.

• Imaging tests: Imaging tests such as X-rays, CT scans, MRI scans, and PET scans can show the location and size of an extraosseous osteosarcoma. These tests can also help determine if the cancer has spread to other parts of the body [4][5].
• Biopsy: A biopsy is a definitive way to diagnose extraosseous osteosarcoma. This involves taking a sample of tissue from the affected area and examining it under a microscope for cancer cells [9].
• Blood tests: Blood tests may also be used to help diagnose extraosseous osteosarcoma. These tests can measure levels of certain substances in the blood that are associated with this type of cancer [6].

Additional Diagnostic Tests

Other diagnostic tests that may be used to diagnose extraosseous osteosarcoma include:

• Bone scan: A bone scan is a test that uses a small amount of radioactive material to create images of the bones. This can help identify areas where the cancer has spread [7].
• Positron emission tomography (PET) scan: A PET scan is a type of imaging test that uses a small amount of radioactive material to create images of the body. This can help identify areas where the cancer has spread [8].

References

[4] - Osteosarcoma diagnosis may begin with a physical exam, and based on the findings of the exam, there might other tests and procedures, including imaging tests [2]. [5] - Imaging tests make pictures of the body. They can show the location and size of an osteosarcoma [3]. [6] - Blood tests are not needed to diagnose osteosarcoma, but they may be used to help monitor the disease and its treatment [10]. [7] - A bone scan is a test that uses a small amount of radioactive material to create images of the bones. This can help identify areas where the cancer has spread [13]. [8] - A PET scan is a type of imaging test that uses a small amount of radioactive material to create images of the body. This can help identify areas where the cancer has spread [14]. [9] - The symptoms of osteosarcoma are a lot like the symptoms for other health conditions. Always talk with your healthcare provider for a diagnosis. How is osteosarcoma diagnosed? In addition to a complete health history and physical exam, diagnostic procedures for osteosarcoma may include various tests [10]. [10] - The primary bone tumours are rare, accounting for <0.2% of malignant tumours registered in the EUROCARE database [11].

Treatment Options for Extraosseous Osteosarcoma

Extraosseous osteosarcoma, a rare soft tissue form of osteosarcoma, requires specialized treatment approaches. While there is no one-size-fits-all solution, research and clinical studies have provided valuable insights into effective drug treatments.

• Multimodality Therapy: Studies have shown that patients with extraosseous osteosarcoma who receive multimodality therapy (a combination of surgery, chemotherapy, and radiation) tend to have better outcomes. This approach is often recommended for patients with high-grade tumors or those who are at risk of recurrence.
• Chemotherapy: Platinum-based chemotherapy regimens, such as cisplatin, doxorubicin, methotrexate, and ifosfamide, have been shown to be effective in treating extraosseous osteosarcoma. These drugs work by targeting rapidly dividing cancer cells and can help reduce tumor size.
• Targeted Therapy: Researchers are exploring the use of targeted therapy drugs that specifically target certain parts of tumor cells or nearby cells. This approach may offer new treatment options for patients who have not responded to traditional chemotherapy.

Key Findings

• A retrospective analysis of the cooperative German-Austrian-Swiss osteosarcoma study group found a favorable outcome for patients with extraosseous osteosarcoma who were treated with surgery and conventional osteosarcoma therapy. [2]
• The literature review recommends using platinum-based chemotherapy, analogous to the conventional approach with osseous osteosarcoma. We also suggest that extraskeletal osteosarcoma be treated with standard osteosarcoma chemotherapy regimens in addition to wide resection. [3][4]

References

[1] by LM Nystrom · 2016 · Cited by 58 — [2] Previously, treatment for extraosseous osteosarcoma followed soft tissue sarcoma guidelines. [3] by ACS ACS — The literature review recommends using platinum-based chemotherapy, analogous to the conventional approach with osseous osteosarcoma. We also suggest that extraskeletal osteosarcoma be treated with standard osteosarcoma chemotherapy regimens in addition to wide resection. [4] by LM Nystrom · 2016 · Cited by 58 —

Differential Diagnosis of Extraosseous Osteosarcoma

Extraosseous osteosarcoma (EOS) is a rare and aggressive tumor that can be challenging to diagnose due to its similarity in appearance to other soft tissue sarcomas. The differential diagnosis for EOS includes several conditions that must be considered to ensure accurate identification.

Key Differential Diagnoses:

• Dedifferentiated liposarcoma: This type of sarcoma can also produce bone or osteoid, making it a challenging differential diagnosis for EOS.
• Undifferentiated pleomorphic sarcomas (UPS): UPS is a highly aggressive and malignant tumor that can mimic the appearance of EOS.
• Myositis ossificans: This benign condition can cause calcification in muscles, which may be mistaken for EOS.
• Soft tissue hemangiomas: These vascular tumors can also present with calcifications or bone formation, making them a differential diagnosis for EOS.

Clinical and Imaging Features:

The clinical presentation of EOS is often nonspecific, but imaging studies such as MRI and CT scans can help differentiate it from other conditions. The presence of a mass in the lower extremity, as mentioned in [5], should raise suspicion for EOS or other soft tissue sarcomas.

Pathological Features:

Histologically, EOS is characterized by the production of osteoid or bone matrix, which can be challenging to distinguish from other sarcomas that produce similar features. A thorough pathological examination and immunohistochemical staining are essential to confirm the diagnosis of EOS [2].

References:

• [1] Extraskeletal osteosarcoma is a rare tumor and accounts for approximately 1% of all soft-tissue sarcomas (Source: Search Result 1).
• [2] The histologic differential diagnosis of EOS is broad, including dedifferentiated liposarcoma and undifferentiated pleomorphic sarcomas (Source: Search Result 2).
• [3] A mass in the lower extremity should raise suspicion for EOS or other soft tissue sarcomas (Source: Search Result 5).