Surgical resection as an adjuvant to tyrosine kinase inhibitors in metastatic GIST: Association or causation?/Are we any closer to an answer?

A Case Report of Multiple Gastrointestinal Stromal Tumors: Imaging Findings, Surgical Approach, and Review of the Literature

Introduction

Multiple gastrointestinal stromal tumors (GISTs) are rare tumors. Differential diagnosis between metastatic and multiple GISTs represents a challenge for a proper workup, prediction prognosis, and therapeutic strategy.

Case presentation

We present the case of 67-year-old man with computed tomography (CT) evidence of multiple exophytic lesions in the abdomen, reaching diameters ranging from 1 to 9 cm, without any signs of organs infiltration, and resulting positive at 18F-FDG-PET/CT. Laparoscopic biopsy revealed multiple GISTs, and surgical resection by using an open approach was performed to achieve radicality. Moreover, an extensive review of the current literature was performed.

Results

Small GISTs (<5 cm) can be treated by the laparoscopic approach, while in the case of large GISTs (>5 cm), tumor location and size should be taken into account to reach the stage of radical surgery avoiding tumor rupture. For metastatic GISTs, Imatinib represents the first choice of treatment, and surgery should be considered only in a few selected cases when all lesions are resectable.

Conclusion

Sporadic multiple GISTs are a rare event, imaging findings are not specific for GISTs, and biopsy requires a secure diagnosis and proper management. In the case of large lesions, with a high risk of vessels injury, laparotomy excision should be considered to achieve radicality and to avoid tumor rupture.

Intra-abdominal desmoid tumors mimicking gastrointestinal stromal tumors - 8 cases: A case report

BACKGROUND

Intra-abdominal desmoid tumors (DTs) can mimic recurrence or progression of gastrointestinal stromal tumors (GISTs). Differential diagnosis is important to avoid unnecessary or inappropriate treatment.

CASE SUMMARY

All 8 patients experienced surgical resection of GIST, and median time to diagnosis of DT was 1.8 years after surgical resection. All sites of DT were in the peritoneum around the surgical sites of GIST. The following clinical suspicion coupled with radiological findings contributed to the suspicion of intra-abdominal DTs: (1) Occurrence of a new single lesion in the peritoneum around the surgical sites of GIST; (2) uncontrolled lesion with imatinib while other lesions being controlled with imatinib; (3) well-defined ovoid shaped lesion with delayed or mild enhancement and absence of necrosis, hemorrhage, and cystic change on computed tomography; and (4) a lesion showing mild or no hypermetabolic activity on 18fluorodeoxyglucose-positron emission tomography, contrary to initially hyperactive lesion of GIST. All DTs were surgically removed except for one unresectable DT and only one DT recurred at another site of peritoneum, which was also surgically removed.

CONCLUSION

Intra-abdominal DT should be a differential diagnosis for a new single lesion in patients with GIST.