Dados do Trabalho

Título

EXTRAGASTROINTESTINAL STROMAL TUMOR OF VASCULAR ORIGIN IN RETROPERITONEUM: CASE REPORT

Apresentação do caso

Female, 39 years old, no comorbities, was hospitalized in Oncology Surgery Service for the investigation of an abdominal mass seen in ultrasound. A CT scan of the total abdomen showed a retroperitoneal tumor with soft tissue density and heterogeneous contrast-enhancement measuring 14.5 cm. Submitted to exploratory laparotomy which identified a cystic lesion with hematic content inseparably involving the aorta and inferior vena cava (IVC), suggesting a tumor of vascular origin. It was noted the presence of nourishing vascular branches coming from the right renal artery, aorta at the level of L3 and right common iliac artery, proceeding with embolization. A surgical resection was performed at R2, with residual lesion in the aorta. Histopathology revealed atypical hypercellular mesenchymal fusocellular neoplasm and immunohistochemistry (IHC) positive for CD34, CD117, desmin and negative for DOG1, concluding that it was a Gastrointestinal Stromal Tumor (GIST). The patient was referred to a clinical oncologist for treatment with Imatinib Mesylate 400 mg/day, remaining in complete clinical remission so far.

Discussão

GIST is the most common mesenchymal neoplasm of the gastrointestinal tract (GIT) and represent 1-2% of all GIT malignant diseases. However, in 5-10% of cases, the tumor is found outside the GIT, originating the so-called extragastrointestinal stromal tumor (EGIST). EGIST cases are rare and lack of reports and publications. Vascular wall EGIST was reported by Ko et al. in 2017, who identified a positive c-kit lesion that was histologically similar to GIST originating from the extraluminal part of the IVC. As for dealing with it, surgery remains the treatment of choice for localized disease, although chemotherapy using tyrosine kinase inhibitor (Imatinib) is also a therapeutic alternative.

Comentários finais

Despite sharing morphological and histological characteristics with GISTs, the clinical and radiological particularities of EGISTs are yet to be totally understood. Thus, becoming evident the importance of describing a primary case of a pathology in IVC, aiming at the inclusion of EGIST in the differential diagnoses of abdominal masses, as well as explaining the relevance of the active search for this tumor in the analysis of the IHC.

Palavras-chave

Extragastrointestinal Stromal Tumor, Gastrointestinal Stromal Tumor, Inferior Vena Cava