Giant and high-risk gastrointestinal stromal tumor in the abdomino-pelvic cavity: A case report

Abstract

Gastrointestinal stromal tumors (GISTs) are benign mesenchymal tumors of the gastrointestinal tract. The clinical presentations of patients with GIST are variable and may be non‑specific. The current study reports the case of a 66‑year‑old man that presented with a gradual enlargement of the abdomen, emaciation, hyperhidrosis and frequent and urgent micturition. A computed tomography (CT) scan of the abdomen revealed a large, heterogeneous, low density mass that occupied the entire abdomino‑pelvic cavity. Magnetic resonance imaging (MRI) identified a high signal intensity on the T2 weighted image and an intermediate signal intensity on the T1 weighted image. A contrast enhanced CT scan and MRI demonstrated the uptake of contrast material. A biopsy revealed that the tumor was composed of spindle cells, and immunohistochemical analysis identified the presence of mast/stem cell growth factor receptors. Together, these results lead to a diagnosis of GIST. The clinical findings, imaging modalities and pathological studies suggested that the GIST was a large and high‑risk tumor located in the abdomino‑pelvic cavity. The final surgical results confirmed these findings. Following conservative treatment with imatnib (400 mg, daily) for 6 months, the tumor became smaller and was suitable for surgery, which the patient received in December 2014. The final surgery confirmed the high‑risk GIST. Subsequent to the surgery, the patient was recommended to continue the use of imatnib with regular CT or MRI reexaminations every 3 months, which are planned to continue for 3 years.