RESUMEN Introduccion: El tumor fusocelular hialinizante con rosetas gigantes es una neoplasia constituida por dos componentes histologicos, uno celular con elementos fusiformes, y el segundo representado por islas bien delimitadas casi acelulares, llenas de material hialino, rodeadas de celulas redondas u ovales, las cuales muestran un perfil inmunohistoquimico inusual, e histogenesis incierta. Objetivo: Instruir a los patologos y clinicos sobre este tumor, su forma de presentacion y diagnosticos diferenciales. Metodologia y resultados: Se presenta el caso de una mujer de 42 anos con masa ubicada en region inguinal, de crecimiento progresivo (1 ano), que se reseca quirurgicamente anatomia patologica informo un tumor fusocelular hialinizante con rosetas gigantes, segun hallazgos morfologicos e inmuno histoquimicos, en correlacion con su localizacion y cuadro clinico. Conclusion: Se hace necesario ampliar el conocimiento sobre esta entidad y de esta forma obtener una adecuada evaluacion de sus criterios pronosticos histologicos, comportamiento clinico y tratamiento. Salud UIS 2010; 42: Palabras clave: Tumor fusocelular hialinizante con rosetas gigantes, fibrosarcoma, sarcoma fibromixoide de bajo grado, inmunohistoquimica ABSTRACT Introduction: The hyalinizing spindle cell tumor with giant rosettes is a neoplasia characterized by both histologic components, one of which is cellular, with spindle-shaped elements and the second represented by well defined almost acellular islands filled with hyaline material surrounded by round to oval cells, which shows an unusual immunohistochemical profile and uncertain histogenesis. Objective: Educate pathologists and clinicians about this tumor, its presentation and differential diagnosis. Methods and results: A case of a 42 year old woman with a mass located in the inguinal region, with progressive growth (1 year), surgically resected and histopathology reported as Hyalinizing spindle cell tumor with giant rosettes according to morphological, immunohistochemical findings correlates with its location and clinical. Conclusion: It is necessary to expand awareness about this condition and thus obtain a proper assessment of histological prognostic criteria, clinical behavior and treatment. Salud UIS 2010; 42: Keywords: Hyalinizing spindle cell tumor with giant rosettes, grade fibromyxoid sarcoma, Immunohistochemistry