szinoviálissarcoma

Szinoviálissarcoma is a rare type of soft tissue sarcoma that typically arises in the vicinity of joints, tendons, and bursae. Despite its name, it does not originate from the synovial membrane itself, but rather from primitive mesenchymal stem cells that have the potential to differentiate into synovial-like cells. It is most commonly found in the extremities, particularly around the knee and ankle, but can also occur in the trunk, head, and neck. Szinoviálissarcoma can affect individuals of any age, though it is more prevalent in young adults.

The exact cause of szinoviálissarcoma is unknown, but it is characterized by a specific chromosomal translocation, t(X;18)(p11;q11), which fuses the SS18 gene with one of three partner genes (SSX1, SSX2, or SSX4). This genetic abnormality is believed to play a key role in the development of the tumor. Clinically, it often presents as a slow-growing, painless mass, although rapid growth and pain can occur, especially if the tumor has invaded surrounding structures.

Diagnosis relies on imaging techniques such as MRI and CT scans, followed by a biopsy for histological confirmation. Szinoviálissarcoma is further classified into monophasic (composed of either spindle cells or epithelioid cells) and biphasic (containing both types of cells) subtypes, and sometimes a poorly differentiated variant. Treatment typically involves a multidisciplinary approach including surgical resection with wide margins, often combined with radiation therapy and sometimes chemotherapy, depending on the stage and grade of the tumor. Prognosis varies depending on factors such as tumor size, location, grade, and the presence of metastasis.