{'fraction_non_alphanumeric': 0.01517706576728499, 'fraction_numerical': 0.0, 'mean_word_length': 5.456521739130435, '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}}
Perforation of the oesophagus by a swallowed foreign body presenting as a mediastinal and pulmonary mass.

Perforation of the oesophagus from any cause, including a swallowed foreign body, usually presents with rapid onset of severe pain, followed by the development of fever, perhaps subcutaneous emphysema, and then septicaemia and shock. Very rarely presentation may be delayed and we report an extremely unusual case where the diagnosis was made four months after perforation, when a chronic mediastinal and pulmonary inflammatory mass containing a swallowed bone was found at thoracotomy.