{'fraction_non_alphanumeric': 0.021241830065359478, 'fraction_numerical': 0.004901960784313725, 'mean_word_length': 5.009803921568627, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Synovial sarcoma of the mediastinum.

Synovial sarcomas are exceedingly rare neoplasms of the mediastinum. We herein report a case of synovial sarcoma occurring in the mediastinum of an 11-year-old boy. The patient presented with superior vena cava syndrome, and the tumor was found located in the upper superior mediastinum. Due to the large size of the tumor making complete removal impossible, an incisional biopsy was performed. The biopsy showed the typical biphasic pattern of synovial sarcoma. After surgery, the patient received radiotherapy and chemotherapy, and was still alive 2 years after diagnosis.