The clinicopathologic characteristics of epithelial neoplasms of the gallbladder is fairly limited, due to its rarity and because of the variability in terminology.
Indraneil Mukherjee Qing Zhao Ruan Jocelyn Villanueva Anupama Agarwal Kishore Agrawal 1: Department of Surgery, 2:Department of Pathology , Staten Island University Hospital , Northwell Health
1 MD
INTRODUCTION • The clinicopathologic characteristics of epithelial neoplasms of the gallbladder is fairly limited, due to its rarity and because of the variability in terminology. • The World Health Organization classification of 2010 added Mucinous cystic neoplasms as a separate entity. • The Category of lntracystic papillary neoplasm was created to encompass a vast spectrum of lesions, ranging from innocuous cyst lined by benign epithelium without atypia to extensive invasive carcinomas of mucinous type. • We present a case of an incidentally found Intra mural Intraductal Papillary Mucinous Neoplasm of the Gallbladder.
CASE PRESENTATION CLINICAL DETAILS: • A 67 year old lady with Post Prandial Right Upper Quadrant Pain. BMI of 27. • Past Medical History of H.Pylori Gastritis which had been eradicated and 3.3 cm stable Liver Hemangioma. • 20 Pack years of smoking. She is no longer an active smoker. IMAGING: • Sonogram for suspected Gallstones, did not show any gallstones. • MRI showed a focal form of adenomyomatosis of the gallbladderfundus and small hemangioma and cysts. • Hepatobiliary Scintigraphy with HIDA(99mTc-hepatic iminodiacetic acid) and CCK(cholecystokinin)-stimulated cholescintigraphy demonstrated a gallbladder ejection fraction of 8%. MANAGEMENT: • She underwent an uneventful Laparoscopic Cholecystectomy for Biliary Dyskinesia. PATHOLOGY: • Grossly gallbladder measured 9 x 3 x 2 cm, with smooth and glistening serosa. The gallbladder contained thin green bile with no stones. The wall measuring 0.1 cm in thickness and the mucosa was unremarkable. • A thin-walled cyst measuring 2.3 x 1.8 x 1.2 cm was seen at the fundus. On cut sections, the cyst contained clear fluid and had a firm, white, 0.1 cm thick wall. • It was deemed to be adenomyoma with low grade mucinous dysplastic process or "mural IPMN" pattern is at the fundus of the gallbladder away from the uninvolved cystic duct margin. • It was deemed safe to assume that this was clinically inconsequential and the patient was not offered any further invasive treatment other than follow up.
Figure 1: Adenomyomatous gallbladder wall and cyst with “mural IPMN” pattern (20x)
Figure 2: Cyst wall with low grade mucinous dysplastic epithelium with papillary configuration (20x)
Figure 3: Cyst wall with low grade mucinous dysplastic epithelium with papillary configuration (100x)
Figure 4: Cyst wall with low grade mucinous dysplastic epithelium with papillary configuration; no ovarian type stroma seen. (200x)
DISCUSSION
CONCLUSION
OUR CASE: • The gallbladder showed an adenomyomatous nodule (AM) ("adenomyomatous hyperplasia" or "adenomyoma") in which low grade mucinous dysplastic process evolved forming the "mural IPMN" pattern. • Characteristic features seen: conglomerate of dilated glands on the wall of the gallbladder forming a mural nodule that mostly spare the surface mucosa. • In one focus of this adenomyomatous nodule, there was a cystically dilated gland lined by dysplastic mucinous epithelium in papillary configuration. The overall picture closely resembled pancreatic intraductal papillary mucinous neoplasms (IPMN) which some authors name "mural IPMN of the gallbladder" or Intracystic papillary neoplasm (ICPN) for such lesions. REVIEW OF LITERATURE: • It is described as malformative or hamartomatous process rather than a true neoplasm itself. • In fact, in some cases, the overall architecture, in particular, the presence of central rudimentary lumen and its complete muscular coat points towards an incomplete duplication occurring on the gallbladder wall. • Adenomyomatous nodules are common incidental findings, and are generally of no known clinical significance although in rare cases neoplastic changes can develop within them, as in our case. • ICPNs are dysplastic lesion more than 1 cm similar to IPMNs and ITPNs of the Pancreas. ICPNs have variable amount of papillary and tubular pattern. Most common have papillary alone which has the highest association with Carcinoma. • IPMN-B can spread along the mucosal surface of the bile duct and it should be widely resected. However literature is limited regarding IPMN of the gall bladder, though depth of invasion has been described as the main prognostic factor.
