{'fraction_non_alphanumeric': 0.02653631284916201, 'fraction_numerical': 0.00558659217877095, 'mean_word_length': 4.925619834710743, '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}}
[A case of retroperitoneal venous aneurysm].

Venous aneurysm is a rare entity and the disease occurring in the retroperitoneal space has been reported in only 4 cases. Therefore, the fifth case of retroperitoneal venous aneurysm on the literature was described. A 59-year-old male was referred to our clinic because of painless large mass in the left abdomen. Computed tomography, ultrasonography, and magnetic resonance imaging revealed a cystic mass at the perinephric space. The resected cyst contained yellow-grayish fluid. The cyst wall was microscopically formed of 4 layers; blood and cholesterin, hyaline, muscle and collagen from the inner to outer side. He is well without any trouble after the operation.