# Rare occurrence of small bowel intussusception due to synchronous metastasis of renal cell carcinoma

## TL;DR

A rare case of kidney cancer spreading to the small intestine and causing intussusception is reported, highlighting the need for awareness of unusual gastrointestinal symptoms in cancer patients.

## Contribution

This paper presents a rare case of synchronous metastasis of renal cell carcinoma to the small bowel presenting as intussusception.

## Key findings

- A 62-year-old man with stage IV clear cell renal carcinoma presented with intestinal intussusception due to a metastatic tumor.
- Surgical resection resolved symptoms and allowed initiation of systemic therapy.
- Intestinal metastases from renal cell carcinoma are rare and pose significant diagnostic challenges.

## Abstract

Renal carcinoma is the third most common urological cancer, with 30% of patients presenting with metastases at diagnosis. Metastases to the small intestine are rare (0.7–1.1%), and their presentation as intestinal intussusception is even more uncommon, with only a few cases reported in the literature.

The aim of the study was to present a case of stage IV clear cell renal carcinoma with a rare presentation of intestinal intussusception, leading to emergency department admission due to severe anemia and melena.

A 62-year-old man presented with melena for 2 months and a critically low hemoglobin level of 2.9 g/dL (normal range: 13.5–17.5 g/dL). Abdominal and pelvic angiotomography identified an exophytic lesion in the left kidney consistent with renal carcinoma and an approximately 16 cm ileal intussusception.

Exploratory laparotomy revealed intestinal intussusception and a 4 cm lesion on the antimesenteric border, suspected to be a tumor. A segmental resection with primary anastomosis was performed, resulting in a favorable postoperative recovery. Histopathological and immunohistochemical analyses confirmed poorly differentiated metastatic clear cell renal carcinoma.

This report underscores the need to consider gastrointestinal symptoms in patients with renal carcinoma, as an intestinal metastasis, although rare, is a potential complication. Synchronous metastases are even rarer and present a significant diagnostic challenge.

Small bowel metastasis from renal cell carcinoma is extremely rare and can present as intussusception, with few cases reported in the literature.

A 62-year-old male presented with anemia and melena and was diagnosed with synchronous small bowel metastasis causing ileal intussusception.

Surgical resection of the affected bowel segment resulted in symptom resolution and allowed initiation of systemic therapy.

This case underscores the importance of considering intestinal metastasis in renal cancer patients with gastrointestinal bleeding or obstructive symptoms.

Renal carcinoma is the third most common urological cancer and the seventh among all neoplasms. Approximately 30% of patients with renal carcinoma present with metastases at diagnosis, with the most frequent sites being the lungs (50–60%), bones (30–40%), liver (3040%), and brain (5%). Metastases to the small bowel are extremely rare (0.7–1.1%) and are usually found when there is diffuse dissemination of the primary tumor, typically presenting as iron deficiency anemia due to occult bleeding or obstructive symptoms.

The presented report underscores the importance of maintaining suspicion for symptoms such as gastrointestinal bleeding, anemia, and intestinal obstruction in patients with renal carcinoma, considering the possibility, albeit rare, of intestinal metastasis. It is important to note that in cases of synchronous metastases, the diagnosis is even more uncommon, and the level of suspicion is more challenging.