Acute Right Lower Abdomen in a Patient with a History of Gastrointestinal Stromal Tumor

BACKGROUND: Gastrointestinal stromal tumor (GIST) is an uncommon tumor of the GI tract usually seen in elderly patients, often difficult to diagnose because of the unspecific symptoms such as abdominal pain and fullness. Recurrent GIST may have an even more obscure clinical presentation. CASE REPORT: A 44-year-old female with a history of surgically treated GIST presented to the emergency room complaining of acute onset sharp RLQ pain, nausea, and vomiting. Clinically, she had RLQ tenderness with rebound, her WBC was elevated, and CT scan showed signs of appendicitis and also soft tissue masses suspicious for malignancy. After contemplating treatment options including antibiotics and further workup, it was recommended to proceed with surgery. Laparoscopy showed a thickened appendix with nodular infiltration and multiple mass-like lesions in the RLQ not amendable to minimal invasive resection. From a lower midline incision, an open appendectomy and excision of multiple masses in the terminal ileum and in the abdominal wall were done. Narrow-based Meckel's diverticulum with multiple nodular lesions was also removed. Pathology identified appendicitis and serosal involvement of GIST in all specimens staining positive for CD68, CD117, and vimentin. The patient was started on imatinib and remained recurrence-free after 6 months. CONCLUSIONS: This case illustrates a rare presentation of acute symptomatic recurrent metastatic GIST. Our patient was unusually young, and GIST recurrence presented with acute RLQ pain suggestive for acute appendicitis and also involved Meckel's diverticulum. Surgical debulking followed by imatinib seems to be a reasonable approach in such cases.