**Core Concept**
Synovial sarcoma is a rare type of cancer that typically occurs near the joints of the arm, neck, or leg. It is a malignant tumor that arises from the synovial tissue, which is a type of connective tissue that surrounds and supports the joints.

**Why the Correct Answer is Right**
Synovial sarcoma is characterized by its location, histological appearance, and molecular features. It typically presents as a painless mass near the joint, and histologically, it shows a biphasic pattern of epithelial and spindle cell components. The tumor cells often express epithelial markers such as EMA and cytokeratins, and molecular studies have identified specific genetic alterations, including the SS18-SSX fusion gene.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because synovial sarcoma typically arises near the joints, but it is not exclusively found in the synovial tissue. It can also occur in other locations, such as the abdominal wall or the neck.
**Option B:** This option is incorrect because synovial sarcoma is a type of cancer that is typically malignant, not benign. While it may present as a painless mass, it has the potential to metastasize and cause significant morbidity.
**Option C:** This option is incorrect because synovial sarcoma is not typically associated with a specific age group or sex. While it may be more common in young adults, it can occur at any age and affects both males and females.

**Clinical Pearl / High-Yield Fact**
One key fact to remember about synovial sarcoma is that it is often misdiagnosed as a benign tumor or a soft tissue injury due to its painless nature and lack of systemic symptoms. A high index of suspicion and careful histological examination are essential for accurate diagnosis and treatment.

**Correct Answer: A. Synovial sarcoma can occur in locations other than near the joints.**