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

BACKGROUND Rectal subepithelial lesions(SELs) are commonly seen in endoscopic examination, generally manifested as bumps with a smooth surface. Precise preoperative diagnoses for rectal SELs are difficult because abnormal tissues are not easily to be obtained by regular endoscopic forceps biopsy. Traditional guidance modalities of preoperative biopsy, including endoscopic ultrasound, computed tomography, and transabdominal ultrasound, are often unsatisfactory. An updated, safe, and effective biopsy guidance method is required. We herein report a new biopsy guidance modality—endorectal ultrasound(ERUS) combined with contrastenhanced ultrasound(CEUS).CASE SUMMARY A 32-year-old woman complained of a mass inside the rectovaginal space for 9 years, which became enlarged within 1 year. A rectal SEL detected by endoscopy was suspected to be a gastrointestinal stromal tumor or exophytic uterine fibroid. Pathological diagnosis was difficult because of unsuccessful transabdominal core needle biopsy with insufficient tissues, as well as vaginal hemorrhage. A second biopsy was suggested after multiple disciplinary treatment discussion, which referred to a transperineal core needle biopsy(CNB) guided by ERUS combined with CEUS. Adequate samples were procured and rectal gastrointestinal stromal tumor was proved to be the pathological diagnosis. Imatinib was recommended for first-line therapy by multiple disciplinary treatment discussion. After the tumor shrunk, resection of the rectal gastrointestinal stromal tumor was performed through the posterior vaginal wall. Adjuvant therapy was applied and no recurrence or metastasis has been found by the last follow-up on December 13, 2019.CONCLUSION Transperineal CNB guided by ERUS and CEUS is a safe and effective preoperative biopsy of rectal SELs yet with some limitations.

Value of contrast-enhanced ultrasound in deep angiomyxoma using a biplane transrectal probe:A case report

BACKGROUND Deep angiomyxoma(DAM)is a very rare tumor type.Magnetic resonance imaging(MRI)is considered the best imaging modality for diagnosing DAM.Computed tomography(CT)is used mainly to assess the invasion range of DAM.The value of ultrasonography in the diagnosis of DAM is still controversial.Through a literature review,we summarized the current state of ultrasonic examination for DAM and reported for the first time the contrast-enhanced ultrasound(CEUS)features of DAM seen using a biplane transrectal probe.CASE SUMMARY A 37-year-old woman presented with a sacrococcygeal mass that had gradually increased in size over the previous 6 mo.MRI and CT examinations failed to allow a definite diagnosis to be made.Transperineal core needle biopsy(CNB)guided by transrectal ultrasound and CEUS was suggested after a multidisciplinary discussion.Grayscale ultrasound of the lesion showed a layered appearance with alternating hyperechoic and hypoechoic patterns.Transrectal CEUS showed a laminated distribution of the contrast agent that was consistent with the layered appearance of the tumor on grayscale ultrasound.We performed transperineal CNB of the enhanced area inside the tumor under transrectal CEUS guidance and finally made a definitive diagnosis of DAM through histopathology.The patient underwent laparoscopic-assisted transabdominal surgery combined with transperineal surgery for large pelvic tumor resection and pelvic floor peritoneal reconstruction.No recurrence or metastasis was found at the ninemonth follow-up.CONCLUSION Transrectal CEUS can show the layered perfusion characteristics of the contrast agent,guiding subsequent transperineal CNB of the enhanced area within the DAM.