# Pazopanib-induced enteritis in a patient with renal cell carcinoma

## TL;DR

A patient with renal cancer developed enteritis from pazopanib, showing extensive inflammation and partial recurrence upon drug resumption.

## Contribution

This case highlights unique features of pazopanib-induced enteritis compared to other tyrosine-kinase inhibitors.

## Key findings

- Discontinuation of pazopanib led to rapid resolution of diarrhea and improvement in colonoscopic findings.
- Resuming pazopanib caused recurrence of gastrointestinal symptoms, indicating a drug-related cause.
- The case showed less bleeding but more widespread inflammation compared to prior reports.

## Abstract

A 69-year-old woman presented to our department with the chief complaint of diarrhea. She had undergone left nephrectomy for renal cancer 14 years earlier. Three years earlier, metastasis was detected in the left retroperitoneal cavity, and pazopanib administration was initiated. In the 29th month after the start of chemotherapy, the patient developed diarrhea, and on the 31st month, computed tomography showed thickening of the intestinal wall. Colonoscopy revealed white villi, intramucosal hemorrhage in the terminal ileum, and rough inflammatory mucosa with inflammatory polyps extending from the transverse to the sigmoid colon. Suspecting pazopanib-induced enteritis, we discontinued the medication, and the diarrhea resolved within 3 days. On the 21st day after discontinuation, colonoscopy revealed that the inflammatory polyps had shrunk, and the inflammatory findings had improved. Biopsy of the white villi of the ileum revealed histiocytes. The patient resumed treatment with pazopanib at 400 mg/day and developed soft stool on the 7th day after resumption. Compared with other tyrosine-kinase inhibitor-induced enteritis cases, this case showed less bleeding and more extensive inflammatory findings. There are similarities as well as differences from cases of previously reported pazopanib-induced enteritis. The mechanisms and characteristics of this disease require further investigation.