{'fraction_non_alphanumeric': 0.02, 'fraction_numerical': 0.0, 'mean_word_length': 5.257352941176471, '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}}
[Malignant melanoma of nasal cavities. Case contributions].

Primitive melanoma of nasal cavities is a rare clinical event. Its pathogenesis is due to the neoplastic development of melanocytes of neuroectodermal origin which are located in the nasal mucosa. Characteristics clinical symptoms are nasal obstruction and recurrent nose-bleeding. In spite of new therapeutic approaches the prognosis of this disease remains severe. No case of primitive malignant melanoma of the nasal cavities has been treated with radiotherapy, according to the authors experience. Sometimes it may be difficult to recognize a cutaneous malignant melanoma because of regression. It may be found after the evidentiation of its recurrences and/or metastasis in different sites. One of the cases here reported came to the authors' attention as ethmoido-frontal metastasis.