A rare case of aberrant pancreas in the colon: choristoma of Bauhin’s valve

A 48-year-old man with normal antenatal history was admitted to hospital with complaints of recurrent nonintensive pain on the right side. The patient had a medical history of Crohn’s disease (remission) for the past 5 years.

Physical and laboratory examinations (including amylase, 45 U/L) were unremarkable. Computed tomography scan revealed wall thickening of the distal ileum up to 0.4 cm. Colonoscopy showed a nonepithelial lesion with a diameter of 0.3 cm and a smooth surface and regular capillary pattern on the lower lip of the Bauhin’s valve (ileocecal valve) ([Fig. 1], [Video 1]). Biopsy was performed and demonstrated mucous glands lying directly under the muscle plate, forming a nodular lesion covered with the usual histological structure of mucous membranes ([Fig. 2]). Paneth cells with bright red granular cytoplasm were found at the base of the crypts (normal for this location in the colon mucosa). Given the lack of available mucous glands in the colon submucosa, this modification is to be seen as a choristoma, and thus, the specimen was identified as a choristoma of the Bauhin’s valve.

Fig. 1 Colonoscopy photographs before biopsy demonstrated a nonepithelial lesion on the lower lip of the Bauhin’s valve. a White-light imaging. b I-SCAN mode.

Video 1 Colonoscopy showing a nonepithelial lesion with a diameter of 0.3 cm and a smooth surface and regular capillary pattern.

Fig. 2 Histopathological section revealed groups of mucous glands surrounded by thin bundles of smooth muscle cells and located in the edematous stroma (hematoxylin and eosin stain). a × 100. b × 250.

At the next stage, the patient underwent endoscopic resection of the lesion with a cold snare. There were no complications in the postoperative period. The patient was discharged on the second day after surgery.

Choristoma (heterotopia, pancreatic ectopia; aberrant pancreas) is a rare, in most cases asymptomatic congenital anomaly, characterized by the presence of a group of pancreatic cells/tissue in an atypical place without neural, vascular, or other anatomical connections with the main pancreas [1]. The first morphologically confirmed case of pancreatic heterotopy was published by Klob in 1859 and, more recently, detailed analysis of morphology and histology has been described [2]. Aberrant pancreas can be located in the stomach (27.5 %), duodenum (25.5 %), and colon (15.9 %) [3] [4]. Rare localizations include biliary tract, liver, spleen, greater omentum, and lungs [3] [4].

We electronically searched PubMed (1984 – July 2019) for the keywords “choristoma colon” and found only 87 articles; for the keywords “choristoma Bauhin’s valve” there are no data.

Endoscopy_UCTN_Code_CCL_1AD_2AJ

Competing interests

None

• References

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• 3 Hirasaki S, Kubo M, Inoue A. et al. Jejunal small ectopic pancreas developing into jejunojejunal intussusception: a rare cause of ileus. World J Gastroenterol 2009; 15: 3954-3956
• 4 Sodhi KS, Fink AM. Education and imaging. Gastrointestinal: aberrant ileal pancreas causing intussusception. J Gastroenterol Hepatol 2009; 24: 322