Journal of the Pancreas Open Access

Keywords

Cystadenoma, Mucinous; Pancreatectomy; Pancreatic Cyst; Viscosity

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 nonmucinous 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”).

Conflict of interest

The authors have no potential conflicts of interest.

References

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