A case of unclassified multicystic biliary tumor with biliary adenofibroma features

Abstract

A 40-year-old Japanese man was admitted to our hospital for evaluation of upper abdominal pain. Abdominal computed tomography (CT) revealed a well-circumscribed multicystic mass measuring approximately 7 × 6 cm. The mass contained a solid lesion measuring 3 × 2 cm. Biopsy of a swollen cervical lymph node led to a diagnosis of diffuse large B-cell lymphoma. After initial chemotherapy for lymphoma, the multicystic mass was surgically resected. The tumor was composed of a multicystic lesion and a solid lesion. Histopathologic examination of the multicystic lesion revealed that the locules were lined by biliary epithelium, demonstrating various degrees of cytological atypia. The stroma was fibrous, and the tumor showed marked apocrine snouts. Part of the tumor showed papillary growth with strong cytological atypia. The solid lesion showed tubulocystic proliferation of tumor cells, with prominent apocrine snouts, embedded in dense and partially hyalinized fibrous stroma. The morphology of the solid part was quite similar to that of reported biliary adenofibroma. Despite lengthy discussion, an appropriate pathological diagnosis could not be found among the current classifications of biliary tumor. The tumor was finally diagnosed as unclassified multicystic biliary tumor with adenofibroma features.

Malignant transformation of biliary adenofibroma: a rare biliary cystic tumor

“…However, imaging alone cannot reliably differentiate biliary cystadenoma from cystadenocarcinoma (13). Moreover, the reports that include imaging findings of malignant BAF are similar to other biliary cystic tumors (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)13). As such, a tissue diagnosis is needed.…”

“…To our knowledge, only 11 cases of BAF have been reported in the literature (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). We performed a database search to find cases of BAF diagnosed at Mayo Clinic from years 1994 to 2016.…”

A problematic case of unclassified multicystic biliary tumor with adenofibroma features

“…However, the first report of biliary adenofibroma documented that moderate atypia was evident in some cysts similar to the present tumor (1). Additionally, two out of seven reported recent cases showed malignant transformation (2,3) and one of them showed local recurrence and distant metastases (3,8). That is why our diagnosis was in the direction of biliary fibroadenoma despite the presence of cellular atypia.…”

“…Since then, few cases of BFA of the liver have been reported in the literature (1)(2)(3)(4)(5)(6)(7)(8). It is characterized by tubulocystic proliferation of variable-sized neoplastic ducts embedded in abundant fibrous stroma.…”

“…The tumor was composed of neoplastic cysts and fibrous stroma only whereas multicystic biliary hamartoma is composed of ducts, periductal glands and connective tissue (8).…”