Ultrasonographic Diagnosis of Sigmoid Colon Schwannoma: Report of One Case and Literature Review.

Sigmoid colon schwannoma is a rare benign gastrointestinal tumor that is challenging to be diagnosed preoperatively.This paper reported a case of sigmoid colon schwannoma that was preoperatively misdiagnosed as a gastrointestinal stromal tumor on ultrasonography.Intraoperative frozen section analysis identified it as a spindle cell tumor,with definitive diagnosis confirmed as gastrointestinal schwannoma via immunohistochemistry.This paper summarizes the similarities and differentiating features of intestinal stromal tumors and schwannomas on ultrasonographic imaging.By analyzing and discussing previous literature,we aim to enhance the diagnostic and differential diagnostic capabilities of ultrasonographers in preoperative evaluation of intestinal schwannomas,thereby providing reliable evidence for clinicians in the diagnosis and management of this condition.