Background: Intravascular large B-cell lymphoma is a rare and aggressive lymphoma with a dismal prognosis. Synchronous intravascular large B-cell lymphoma involving gastrointestinal stromal tumor has not previously been documented.
Case presentation: We report a case of a 61-year-old Chinese woman who presented with high fever of unknown origin for 20 days, and hematemesis, melena for 2 days. A computed tomography scan revealed a mass lesion located in the anterior wall of the stomach. Surgery was performed to remove the tumor and histopathology showed a gastrointestinal stromal tumor and a synchronous intravascular large B-cell lymphoma. The patient refused further treatment and died 4 months after surgery.
Conclusions: To the best of our knowledge, this case represents the first report of synchronous intravascular large B-cell lymphoma involving a gastrointestinal stromal tumor.