{'fraction_non_alphanumeric': 0.021798365122615803, 'fraction_numerical': 0.014986376021798364, 'mean_word_length': 5.074380165289257, '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}}
Growing teratoma syndrome after chemotherapy for germ cell tumour of the ovary

Malignant teratoma is an uncommon ovarian germ cell tumour which behaves aggressively (Caldas et al. 1992). It makes up 2 – 10% of ovarian tumours. Studies of germ cell tumours of the testes and ovaries have shown that tumour growth or persistence during or after chemotherapy may be caused by necrosis, fibrosis or growth of mature teratomatous elements and not just by progression of the malignant neoplasm. Since the introduction of postoperative chemotherapy cases of transformation of this malignant tumour into mature teratoma (retroconversion) have been described (Geisler et al. 1994). We report a case of retroconversion of a malignant teratoma.