MULTIMEDIA ARTICLE – Clinical Imaging

JOP. J Pancreas (Online) 2014 Mar 10; 15(2):206-207.

Endoscopic “String Sign”

Jesus Espinel¹, Eugenia Pinedo², Gabriela Rascarachi³, Vanesa Ojeda⁴

¹Endoscopy Unit and ²Department of Radiology, Hospital de León. León, Spain. ³Endoscopy Unit, Hospital del Bierzo. Ponferrada, Spain. ⁴Department of Digestive Diseases, Dr. Negrín University Hospital. Las Palmas de Gran Canaria, Spain

A 76-year-old female patient was admitted at hospital with diarrhea, weight loss, fatigue and abdominal pain. Her physical examination and laboratory test were normal; however, the radiological images showed an atrophic pancreas with cystic dilatation of the main pancreatic duct. Severe dilatation of the main pancreatic duct was confirmed on EUS, with the presence of round images of mucinous aggregates within (droplets of mucous plug). In view of these findings, we performed a duodenoscopy, which showed mucin extrusion from a patent ampulla (a “fish-mouth” look-like patulous papilla with mucus excretion from the orifice; Image 1), a pathognomonic finding of intraductal papillary mucinous tumor (IPMT) of the main pancreatic duct. We obtained blind biopsies and the histological results confirmed the diagnosis of IPMT. After removing the duodenoscope, a mucus string of about 40 cm in length was adhered to the biopsy channel of the duodenoscope (Image 2).

Image 1

Image 2

Viscosity is one of the main features which might help on the diagnosis of a pancreatic cystic lesion. It is useful to distinguish mucinous from non-mucinous cystic lesions. Cystic fluid from serous cystadenomas and pseudocysts had mean relative viscosity values of 1.24 and 1.25 respectively. By contrast, mean relative viscosity values of mucinous cysts were significantly higher, ranging from 1.2 to 30 [1]. A recent study concluded that viscosity greater than 1.6 predicted mucinous cystic adenoma/adenocarcinoma [2]. A novel surrogate marker of cyst viscosity was used by Leung et al., and it was described as the “string sign” [3]. This test was determined by placing a drop of fluid between the thumb and index finger and measuring the maximum length of stretch before disruption of the mucous string. The authors concluded that a long string sign (greater than 3.5 mm) has a high predictive value for a mucinous lesion. The string sign is a simple technique which could help to supplement the diagnosis of cystic lesions.

In our case, we obtained a very long string sign (about 40 cm in length) with the help of the duodenoscope (“endoscopic string sign”).

Received September 11^th, 2013 – Accepted December 11^th, 2013

Key words Cystadenoma, Mucinous; Pancreatectomy; Pancreatic Cyst; Viscosity

Conflict of interest The authors have no potential conflicts of interest

Correspondence
Jesus Espinel
c/ Santos Olivera nº30, 4º-B
24.005-León
Spain
Phone: +34-987.237.400
Fax: +34-987.235.318
E-mail: espinel.jesus@gmail.com

References

1. Lewandrowski KB, Southern JF, Pins MR, Compton CC, Warshaw AL. Cyst fluid analysis in the differential diagnosis of pancreatic cysts. A comparison of pseudocysts, serous cystadenomas, mucinous cystic neoplasms, and mucinous cystadenocarcinoma. Ann Surg. 1993; 217(1):41-7. [PMID: 8424699]

2. Linder JD, Geenen JE, Catalano MF. Cyst fluid analysis obtained by EUS-guided FNA in the evaluation of discrete cystic neoplasms of the pancreas: a prospective single-center experience. Gastrointest Endosc. 2006; 64(5):697-702. [PMID: 17055859]

3. Leung KK, Ross WA, Evans D, Fleming J, Lin E, Tamm EP, et al. Pancreatic cystic neoplasm: the role of cyst morphology, cyst fluid analysis, and expectant management. Ann Surg Oncol. 2009; 16 (10):2818-24. [PMID: 19536601]