Transperineal core-needle biopsy of a rectal subepithelial lesion guided by endorectal ultrasound after contrast-enhanced ultrasound: A case report

Table 1 Timeline of diagnosis and treatment process

Time	Events
January 2018	A mass in the rectovaginal space found 9 years ago had significantly grown in a year, with several times of negative endoscopy biopsy results
January 31, 2018	Transabdominal biopsy failed to provide qualified tissues to make well-defined pathological result
February 8, 2018	The patient underwent transperineal biopsy guided by ERUS and CEUS, diagnosed as rectal GIST
July 23, 2018	The tumor shrunk after 5-mo imatinib treatment, and was completely resected through the posterior vaginal wall
October 13, 2019	Fifteen months after tumor resection, no obvious sign of recurrence was found

ERUS: Endorectal ultrasound; CEUS: Contrast-enhanced ultrasound; GIST: Gastrointestinal stromal tumor.