Hepatobiliary Mucinous Cystic Neoplasms With Ovarian Type Stroma (So-Called “Hepatobiliary Cystadenoma/Cystadenocarcinoma”)

Abstract

The literature is highly conflicting on hepatobiliary mucinous cystic neoplasms (MCNs), aka "hepatobiliary cystadenoma/cystadenocarcinoma," largely because ovarian stroma (OS) was not a requirement until WHO-2010 and is not widely applied even today. In this study, MCNs (with OS) accounted for 24 of 229 (11%) resected hepatic cysts in one institution. Eight of the 32 (25%) cysts that had been originally designated as hepatobiliary cystadenoma/cystadenocarcinoma at the time of diagnosis proved not to have an OS during this review and were thus re-classified as non-MCN. In total, 36 MCNs (with OS) were analyzed-24 from the institutional files and 12 consultation cases. All were women. Mean age was 51 (28 to 76 y). Mean size was 11 cm (5 to 23 cm). Most (91%) were intrahepatic and in the left lobe (72%). Preoperative imaging mentioned "neoplasm" in 14 (47%) and carcinoma was a differential in 6 (19%) but only 2 proved to have carcinoma. Microscopically, only 47% demonstrated diffuse OS (>75% of the cyst wall/lining); OS was often focal. The cyst lining was often composed of non-mucinous biliary epithelium, and this was predominant in 50% of the cases. Degenerative changes of variable amount were seen in most cases. In situ and invasive carcinoma was seen in only 2 cases (6%), both with small invasion (7 and 8 mm). Five cases had persistence/recurrence, 2 confirmed operatively (at 7 mo and 15 y). Of the 2 cases with carcinoma, one had "residual cyst or hematoma" by radiology at 4 months, and the other was without disease at 3 years. In conclusion, many cysts (25%) previously reported as hepatobiliary cystadenoma/cystadenocarcinoma are not MCNs. True MCNs are uncommon among resected hepatic cysts (11%), occur exclusively in females, are large, mostly intrahepatic and in the left lobe (72%). Invasive carcinomas are small and uncommon (6%) compared with their pancreatic counterpart (16%). Recurrences are not uncommon following incomplete excision.

Multiple KRAS mutations in the non‐mucinous epithelial lining in the majority of mucinous cystic neoplasms of the pancreas

“…considered MCNs with predominant NMLE to be the same as MCNs with mucinous epithelium, in spite of the differences in malignant potential between the two groups . NMLE is observed not only in pancreatic MCNs but also in hepatobiliary MCNs …”

“…6 NMLE is observed not only in pancreatic MCNs but also in hepatobiliary MCNs. 8 The somatic genetic drivers of MCNs include KRAS, RNF43, p16/CDKN2A, and TP53. 9-11 KRAS mutations occur in 6-50% of MCNs with low-grade dysplasia, depending on the detection method.…”

Differentiation and management of hepatobiliary mucinous cystic neoplasms: a single centre experience for 8 years

“…[11] IBC and IBAC are rare liver cystic tumours that were redefined as H-MCNs by WHO 2010 with the presence of an ovarian-like stoma (OS), occupying only 5% of liver cystic lesions. [3,6,7] H-MCNs are much more aggressive than HSC. BAC tends to transform into IBAC at about 20%.…”

“…[5] By the year of 2010, the World Health Organization (WHO) redefined that the OS is the requirement for the diagnosis the cystadenoma both in liver and pancreas, and uniformly rename the IBC and IBAC as hepatobiliary mucinous cystic neoplasms (H-MCNs). [6,7] Although H-MCNs were defined by the new standard, the preoperative diagnosis of H-MCNs remains quite tricky. Notably, even the equipment of diagnosis have been improving quite a lot, such as contrasted-enhanced ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI), the differential diagnosis for H-MCNs and HSC was still a big challenge.…”

A giant bleeding liver mucinous cystic neoplasm

“…MCNs represent 11% of all resected hepatic cysts, and occur as multilocular cystic lesions with rare malignant transformation . Although capsular ruptures may occur in hepatic masses regardless of their nature, this is unlikely in MCNs due to the thick fibrous capsule.…”