{'fraction_non_alphanumeric': 0.023086269744835967, 'fraction_numerical': 0.0, 'mean_word_length': 5.92436974789916, '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}}
Spindle cell neoplasm of skin: diagnostic dilemma.

Poorly differentiated, spindle cell malignancies, on sun damaged skin frequently pose a diagnostic challenge for pathologists. The vast majority of these neoplasms ultimately are diagnosed as either atypical fibroxanthoma (AFX), spindle cell melanoma (SCM), and very rarely as spindle cell squamous cell carcinoma (SCSCC), leiomyosarcoma or angiosarcoma. Light microscopic clues may suggest one of these neoplasms, but subtle and overlapping characteristics often render precise diagnosis impossible based on morphological features alone. Immunohistochemistry therefore is necessary to firmly and accurately diagnose the majority of spindle cell malignancies on sun damaged skin. Aim of this case report is to highlight the practical approach to such diagnostic dilemmas.