RESUMO
Introduction:Specific management schemes of the exceedingly rare primitive mesenchymal leiomyosarcomasdo not exist. Reporting their behavior and management is necessary to be able to construct evidence-based directives. Case Report:We report a case of a 42-year-old Caucasian woman that presented with a large indolent abdominal mass evolving over 3 months. Two differential diagnosis were looked upon, either GIST or leiomyosarcoma. The abdomino-pelvic ct-scan proved that this tumor could be completely resected, so the patient was successfully operated within 2 weeks of the preliminary diagnosis. A monoblocnegative margin resection was performed and the patient recovered on the surgical floor. The anatomopathological studies and immunohistochemistry tests confirmed the presence of a primitive mesenchymal leiomyosarcoma. The patient was recommended a follow up every 4 months with a thoraco-abdomino-pelvic ct-scan due to her economic status. Conclusion:The management of rare tumors is always challenging due to the lack of knowledge concerning its behavior and response to the various treatment modalities. Reporting this rare case of mesenchymal leiomyosarcoma and similar cases will enable a better understanding of this disease and its treatment.