Transrectal endoscopic ultrasound-guided fine-needle aspiration biopsy for qualitative diagnosis of pelvic space-occupying lesions: a diagnostic test.

Background: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is an effective technique for qualitative diagnosis of space occupying lesions in and around the wall of the digestive tract. At present, there are many studies on EUS-FNA via the upper gastrointestinal route, while there are few studies on EUS-FNA via the lower gastrointestinal route, especially for Chinese patients with pelvic mass. Therefore, this study sought to evaluate the value of transrectal EUS-FNA in the qualitative diagnosis of pelvic masses in Chinese patients. Methods: The clinical data of 35 patients with pelvic masses who underwent EUS-FNA at our hospital were collected from September 2014 to December 2021. Among these patients, 10 underwent surgical treatment after EUS-FNA, and a diagnosis was made based on a pathologic evaluation. The EUS-FNA biopsy results were compared to the final diagnostic results to calculate the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of EUS-FNA in the diagnosis of malignant pelvic mass. For the 10 patients who underwent surgery, the final diagnoses were based on the pathologic findings of surgical specimens, and for the 25 patients who did not undergo surgery, the final diagnoses were based on the malignant pathological results of EUS-FNA or clinical follow-up results. Results: Among the 35 patients, 12 had benign lesions, including pelvic abscesses, cysts, and inflammatory masses, and 23 had malignant lesions, including mesenchymal tumors, leiomyosarcomas, teratomas, and malignant tumors with pelvic metastases. There were no complications resulting from the biopsy punctures. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EUS-FNAs for the diagnosis of malignant pelvic masses were 91.3% (21/23), 100.0% (12/12), 100.0% (21/21), 85.7% (12/14), and 94.3% (33/35), respectively. Conclusions: EUS-FNA is a safe and effective method for the qualitative diagnosis of pelvic masses, and has good clinical application value.