# Case Report: Renal metastasis of a gastric gastrointestinal stromal tumor mimicking a primary renal carcinoma

## TL;DR

A patient with a history of gastric GIST developed aggressive renal metastasis, highlighting the need for early detection and multimodal treatment.

## Contribution

This case report provides insights into the diagnosis and management of rare renal metastasis from GIST.

## Key findings

- Renal metastasis from GIST is uncommon and highly aggressive.
- Surgical resection may offer palliation but long-term survival requires multimodal therapy.
- Early detection of metastatic lesions is crucial for better outcomes.

## Abstract

Gastrointestinal stromal tumors (GISTs), mesenchymal neoplasms of the gastrointestinal tract, are prone to recurrence and metastasis. Despite improvements in prognosis with targeted treatments, such as imatinib, some patients develop metastatic GIST. Renal involvement in GIST is uncommon, and data on the diagnosis and treatment of GIST with renal metastasis remain limited. In this report, we describe the diagnostic and therapeutic regimen used for a patient with renal metastasis from GIST, providing an important reference for clinicians.

A 52-year-old man underwent resection of a gastric GIST 5 years previously and had received adjuvant imatinib therapy for 2 years. A radical nephrectomy was performed, and histopathological analysis confirmed metastatic GIST. Although the patient resumed imatinib therapy post-surgery, follow-up imaging 22 months later revealed multiple metastases in the retroperitoneum and abdominal cavity.

Renal metastasis from GIST is highly aggressive. Although surgical resection offers considerable palliation and may prolong survival, survival is generally dependent on sustained multimodal therapy and follow-up. Early detection and management of recurrent or metastatic lesions are imperative to optimize long-term outcomes.