Warning: XSLTProcessor::transformToXml() [xsltprocessor.transformtoxml]: I/O warning : failed to load external entity "file:////srv/scielo/www/bases/xml/ms/v22n1/1727-897X-ms-22-01-177.xml" in /srv-new/scielo/www/htdocs/class.XSLTransformerPHP5.php on line 36 Acantosis nigricans maligna y carcinoma mamario. Presentación de un caso