spindle cell synovial sarcoma

Spindle cell synovial sarcoma, also known as monophasic synovial sarcoma, is a rare type of soft tissue cancer that develops in the deep tissues of the arms, legs, and feet. It is characterized by the presence of spindle cells, which are elongated cells with a spindle-like shape.

Key Features:

• Comprised entirely of spindle cells
• No epithelial components present
• Can be found in deep tissues of the arms, legs, and feet
• Rare type of soft tissue cancer

According to [1], spindle cell synovial sarcoma is one of the three variants of synovial sarcoma, with the other two being biphasic and poorly differentiated. This variant is characterized by the presence of spindle cells only, without any epithelial components.

In terms of microscopic (histologic) description, spindle cell synovial sarcoma is typically composed of fibroblast-like spindle cells that are similar in appearance to those found in monophasic spindle cell subtype [4].

References:

[1] - Monophasic variant, where the tissue is comprised entirely of spindle-cells (Source: 2) [4] - Microscopic (histologic) description. General (Ann Diagn Pathol 2014;18:369): 2 main subtypes: biphasic and monophasic spindle cell subtype (Source: 4)

Common Signs and Symptoms of Spindle Cell Synovial Sarcoma

Spindle cell synovial sarcoma, a rare type of soft tissue cancer, can manifest in various ways depending on the tumor's size, location, and growth rate. Here are some common signs and symptoms associated with this condition:

• Bone pain: A constant or intermittent ache in the affected bone is a frequent complaint among patients.
• Swelling or lump under the skin: The first noticeable symptom is often a swelling or lump near the joint where the cancer has developed.
• Broken bone (pathological fracture): Weakened bones can lead to fractures, which may be painful and require medical attention.
• Pain or numbness: As the tumor grows, it can press on nerves, causing pain or numbness in the affected area.

Other Possible Symptoms

While not as common, other symptoms that may occur include:

• Weight loss
• Fatigue
• Loss of appetite
• Swollen lymph nodes

Important Notes

It's essential to note that spindle cell synovial sarcoma can be slow-growing and may not cause noticeable symptoms in the early stages. As a result, diagnosis often occurs when the tumor has grown significantly or has caused complications.

References:

[1] Synovial sarcoma is a rare type of cancer that tends to occur near large joints, mainly the knees. (Source: Search Result 3) [2] Symptoms vary depending on tumor size, number of tumors, and which bones contain cancer cells. (Source: Search Result 2) [3] The lump may or may not be painful, but it's often a noticeable swelling under the skin. (Source: Search Result 8) [4] Early diagnosis and treatment are crucial for improving outcomes in spindle cell synovial sarcoma patients. (Source: Search Result 9)

Treatment Options for Spindle Cell Synovial Sarcoma

Spindle cell synovial sarcoma is a rare and aggressive type of cancer that requires prompt and effective treatment. While there are no specific guidelines for the treatment of this subtype, various therapies have been explored to manage the disease.

• Surgery: The primary goal of surgery in spindle cell synovial sarcoma is to remove the tumor completely, if possible. This may involve resection of the affected limb or part of it.
  • [3] mentions that CT scans can show if the cancer has spread to soft tissue, and are best for detecting potential fractures or areas of bone weakening.
• Chemotherapy: Chemotherapy is often used in conjunction with surgery to treat spindle cell synovial sarcoma. The goal is to kill any remaining cancer cells after surgery.
  • [4] states that as doctors learn more about the biology of sarcoma cells, targeted therapy is becoming an important treatment option for some soft tissue sarcomas.
• Targeted Therapy: Targeted therapy involves using medications that specifically target the genetic mutations driving the growth of spindle cell synovial sarcoma cells. Pazopanib (Votrient) is one such medication that has shown promise in treating this type of cancer.
  • [4] mentions that pazopanib blocks several cell enzymes called tyrosine kinases that are important for cell growth and survival.
• Immunotherapy: Immunotherapy involves using medications that stimulate the immune system to attack cancer cells. Afamitresgene autoleuecel (Tecelra) is an immunotherapy medication that has been approved by the FDA for the treatment of adults with synovial sarcoma.
  • [5] states that afami-cel is the first engineered T cell therapy to receive FDA approval for a solid tumor cancer.

Current Research and Future Directions

Researchers are actively exploring new treatments for spindle cell synovial sarcoma, including γ-secretase inhibitors (Notch and WNT/β-catenin pathway) and kinase inhibitors. These novel therapies aim to target specific genetic mutations driving the growth of this type of cancer.

• [7] mentions that medications currently under investigation for treatment of STS with novel mechanisms of action include γ-secretase inhibitors.
• [9] states that we can also treat with the kinase inhibitor pazopanib, an approved type of targeted therapy designed to stop or slow the growth of cancer cells.

The differential diagnosis for spindle cell synovial sarcoma includes several types of sarcomas and other neoplasms that can present with similar histological features.

Key Differential Diagnoses:

• Malignant Peripheral Nerve Sheath Tumor (MPNST): This type of tumor is characterized by its spindle cell morphology, which can be similar to synovial sarcoma. However, MPNST typically lacks the biphasic or monophasic pattern seen in synovial sarcoma [5].
• Fibrosarcoma: Fibrosarcoma is a type of soft tissue sarcoma that can present with spindle cell morphology, making it difficult to distinguish from synovial sarcoma. However, fibrosarcoma typically lacks the characteristic t(X;18)(p11.2;q11.2) translocation associated with synovial sarcoma [10].
• Leiomyosarcoma: This type of tumor is characterized by its spindle cell morphology and can be difficult to distinguish from synovial sarcoma. However, leiomyosarcoma typically expresses smooth muscle markers such as h-caldesmon and caldesmon [14].
• Rhabdomyosarcoma: This type of tumor is a pediatric malignancy that can present with spindle cell morphology, making it difficult to distinguish from synovial sarcoma. However, rhabdomyosarcoma typically expresses muscle markers such as desmin and myogenin [14].

Other Differential Diagnoses:

• Spindle Cell Carcinoma: This type of tumor is characterized by its spindle cell morphology and can be difficult to distinguish from synovial sarcoma. However, spindle cell carcinoma typically lacks the characteristic t(X;18)(p11.2;q11.2) translocation associated with synovial sarcoma [10].
• Solitary Fibrous Tumor/Hemangiopericytoma: This type of tumor is characterized by its spindle cell morphology and can be difficult to distinguish from synovial sarcoma. However, solitary fibrous tumor/hemangiopericytoma typically expresses CD34 and lacks the characteristic t(X;18)(p11.2;q11.2) translocation associated with synovial sarcoma [10].

Molecular Diagnostic Techniques:

• FISH (Fluorescence In Situ Hybridization): This technique can be used to detect the characteristic t(X;18)(p11.2;q11.2) translocation associated with synovial sarcoma, helping to distinguish it from other types of sarcomas [10].
• Immunohistochemistry (IHC): This technique can be used to express markers such as keratin and EMA, which are typically positive in synovial sarcoma. However, IHC results should be interpreted in conjunction with histological features and molecular diagnostic techniques [15].

In summary, the differential diagnosis for spindle cell synovial sarcoma includes several types of sarcomas and other neoplasms that can present with similar histological features. Molecular diagnostic techniques such as FISH and IHC can be used to help distinguish synovial sarcoma from other types of sarcomas.