An ileal gastrointestinal stromal tumor misdiagnosed as pelvic metastases from rectal cancer: a case report

Abstract

With the advancement of imaging and pathological diagnostic methods, it is not uncommon to see synchronous gastrointestinal stromal tumors (GIST) and other primary cancers, the most common of which are synchronous gastric cancer and gastric GIST. However, synchronous advanced rectal cancer and high-risk GIST in the terminal ileum are extremely rare, and they are easily misdiagnosed as rectal cancer with pelvic metastases due to their special location near iliac vessels. Herein, we report a 55-year-old Chinese woman with rectal cancer. Preoperative imaging revealed a middle and lower rectal lesion with a right pelvic mass (considered possible metastasis from rectal cancer). Through multidisciplinary discussions, we suspected the possibility of rectal cancer synchronous with a GIST in the terminal ileum. Intraoperative exploration by laparoscopy revealed a terminal ileal mass with pelvic adhesion, a rectal mass with plasma membrane depression, and no abdominal or liver metastases. Laparoscopic radical proctectomy (DIXON) plus partial small bowel resection plus prophylactic loop ileostomy was performed, and the pathological report confirmed the coexistence of advanced rectal cancer and a high-risk ileal GIST. The patient was treated with the chemotherapy (CAPEOX regimen) plus targeted therapy(imatinib) after surgery, and no abnormalities were observed on the follow-up examination. Synchronous rectal cancer and ileal GIST are rare and easily misdiagnosed as a rectal cancer with pelvic metastases, and careful preoperative imaging analysis and prompt laparoscopic exploration are required to determine the diagnosis and prolong patient survival.

Concurrent Stage III Unresectable Duodenal Adenocarcinoma and Metastatic Gastrointestinal Stromal Tumor Treated With Combination of Imatinib and mFOLFIRI

“…One case report demonstrated that apatinib monotherapy can induce partial response in synchronous GIST and primary gastric adenocarcinoma following the progression of both tumors on a combination of imatinib and S1 (oral fluoropyrimidine) therapy [ 7 ]. In another case, adjuvant CAPOX + 400 mg imatinib showed efficacy in limiting the progression of disease in synchronous rectal cancer and GIST [ 15 ]. In the present case, we had to perform treatment of a synchronous duodenal adenocarcinoma and GIST metastatic to the peritoneum in a patient who had already failed FOLFOX and mFOLFIRI therapy.…”

“…However, limited data exists outlining proper procedure in cases of an inoperable primary GI malignancy and a concurrent inoperable metastatic GIST. First-line medical therapy for small bowel adenocarcinoma is typically oxaliplatin-based regimens such as capecitabine plus oxaliplatin (CAPOX) or leucovorin, 5-fluorouracil, oxaliplatin (FOLFOX) [ 15 ]; however, most patients with GIST are treated with imatinib or other tyrosine kinase inhibitors (TKIs) [ 15 , 16 ]. Concurrent treatment has largely been avoided in previous studies due to risks of severe neutropenia on a combined regimen of a TKI and standard chemotherapy regimens [ 15 - 17 ].…”

“…First-line medical therapy for small bowel adenocarcinoma is typically oxaliplatin-based regimens such as capecitabine plus oxaliplatin (CAPOX) or leucovorin, 5-fluorouracil, oxaliplatin (FOLFOX) [ 15 ]; however, most patients with GIST are treated with imatinib or other tyrosine kinase inhibitors (TKIs) [ 15 , 16 ]. Concurrent treatment has largely been avoided in previous studies due to risks of severe neutropenia on a combined regimen of a TKI and standard chemotherapy regimens [ 15 - 17 ]. Here, we will outline the successful ongoing management of stage IIIA locally advanced/unresectable duodenal adenocarcinoma with concurrent metastatic small intestinal GIST with a combined TKI and chemotherapy regimen on a patient who initially failed standard of care FOLFOX therapy.…”