# Gastrointestinal stromal tumor with small cell carcinoma infiltration: a case report

## TL;DR

A rare case of a gastrointestinal stromal tumor with small cell carcinoma infiltration is reported, highlighting an unusual cancer combination.

## Contribution

This case report presents a rare coexistence of GIST and small cell carcinoma, adding to the understanding of complex tumor interactions.

## Key findings

- A patient was diagnosed with GIST infiltrated by small cell carcinoma through core needle biopsy.
- The patient is undergoing chemotherapy with etoposide and cisplatin.
- The case highlights the importance of thorough pathological examination for rare tumor combinations.

## Abstract

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the digestive system. They usually occur in the gastrointestinal tract. However, we discovered a rare phenomenon in which small cell carcinoma infiltrated the GIST of a patient. The patient came to the hospital and presented with chest tightness and shortness of breath for 2 months and a dry cough for half a month. As the ancillary tests were refined, it was discovered that he also had a lesion in the pelvic cavity. After pathological examination of the core needle biopsy (CNB) samples from the pelvic cavity lesion, the patient was diagnosed with GIST with small cell carcinoma infiltration. The patient is currently receiving a chemotherapy regimen of etoposide combined with cisplatin.