Successful transcolonic endoscopic ultrasound-guided fine-needle biopsy of retroperitoneal fibrosis

A 54-year-old man presented to our department with a 2-month history of back pain and painful urination. A contrast-enhanced computed tomography (CT) revealed a large retroperitoneal soft tissue mass encircling the abdominal aorta, surrounding vessels, and the right ureter ([Fig. 1]). He had an average leukocyte level (7300/µL), within the normal range for tumor markers and IgG4 levels, and a C-reactive protein level of 38.88 mg/L. The clinical picture was highly suggestive of retroperitoneal fibrosis (RPF); however, for a definite diagnosis, a biopsy of the lesion was necessary.

Fig. 1 Contrast-enhanced computed tomography showed an abnormal retroperitoneal soft tissue mass encircling the abdominal aorta.

CT-guided aspiration biopsy was not an option as the blood vessels and bowel could not be avoided. Therefore, endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) was selected as the optimal method for obtaining tissue samples, as it is a minimally invasive technique that has previously demonstrated efficacy.

We decided to perform transcolonic EUS-FNB because of the lesion’s proximity to the pelvis ([Video 1]). In addition to avoiding adjacent blood vessels, transcolonic EUS-FNB allows for a comprehensive view of the lesion from all sides. Therefore, we proceeded with an ultrasound endoscope (EG-3870UTK; Pentax, Tokyo, Japan) to the ileocecal region and then withdrew the endoscope to observe and select the optimal puncture position when the lesion was visible.

Transcolonic endoscopic ultrasound-guided fine-needle biopsy of retroperitoneal fibrosis.Video 1

EUS disclosed a diffuse echo-reduced mass surrounding the distal aorta ([Fig. 2]), and Doppler imaging confirmed the absence of interpolated vessels. Subsequently, two locations in the ascending colon were selected for lesion puncture using a 22-gauge ultrasound biopsy needle (Cook EchoTip Procore HD Endobronchial Ultrasound Biopsy, G34281; Cook Medical, Bloomington, Indiana, USA). Biopsy results confirmed a definite histopathologic diagnosis of RPF ([Fig. 3]), and immunohistochemical analysis indicated CD38 and Congo red staining positivity. The patient did not experience any severe adverse events, and he was successfully treated with prednisolone and azathioprine.

Fig. 2 Transcolonic endoscopic ultrasound revealed a retroperitoneal, diffuse echo-reduced mass suggestive of retroperitoneal fibrosis.

Fig. 3 Histopathologic image of the specimen obtained from endoscopic ultrasound-guided fine-needle biopsy, showing fibrous tissue in cells, together with lymphocytes between the connective tissue fibers.

EUS-FNB can become a safe and effective diagnostic method for RPF [1]. Transduodenal EUS-FNB is unable to penetrate lesions in close proximity to the pelvic cavity. Conversely, transcolonic EUS-FNB can be utilized to identify and select multiple potential puncture sites while avoiding the vicinity of blood vessels, thereby ensuring a safe and precise procedure. Therefore, in cases of RPF affecting the lower abdomen or the region in proximity to the pelvis, a transcolonic EUS-FNB may be a viable option for diagnosis.

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Conflict of Interest

The authors declare that they have no conflict of interest.

• Reference

• 1 Wiedbrauck D, Flemming P, Hollerbach S. A case of idiopathic retroperitoneal fibrosis (Ormond’s disease) diagnosed by transduodenal EUS-guided fine-needle aspiration/biopsy. Gastrointest Endosc 2024; 99: 1069-1070

Publikationsverlauf

Artikel online veröffentlicht:
11. Februar 2025