Malignant transformation of biliary adenofibroma: a rare biliary cystic tumor

Abstract

Biliary adenofibromas (BAFs) are rare, benign biliary cystic tumors with potential for malignant transformation. Of the eleven prior cases of BAF reported in the literature, six showed evidence of malignant transformation. We describe the clinical, imaging and pathology features of two cases of malignant BAF and review the existing literature to raise awareness of this entity and provide additional tools for diagnosing this rare tumor Additionally, we identified a loss of function mutation in the cyclin-dependent kinase inhibitor 2A (CDKN2A) tumor suppressor gene in a malignant caudate lobe BAF, thereby providing potential insight into the molecular pathogenesis of BAF malignant transformation. Although additional cases and longer-term follow-up are needed, our cases suggest that recurrence or metastasis of malignant BAF is not common and that complete surgical resection can be curative.

A case of biliary adenofibroma of the liver with malignant transformation: a morphomolecular case report and review of the literature

“…Similar to the cases described in the literature (Table 1), the presented neoplasia morphologically showed a characteristic structure of a biliary adenofibroma with tubulocystic biliary epithelium and a broad fibrous, non-ovarian-like stroma. In addition, a partly abrupt, partly gradual transformation into more cell-dense tumor areas could be seen, which histologically showed characteristics of an invasive carcinoma in the form of microcystic, fine-papillary and partly cribriform epithelial formations with distinct nuclear atypia and an increased mitotic rate, comparable to the two cases described by Thompson et al with a very similar architecture [15].…”

“…Molecular pathology studies of the biliary adenofibroma have not been extensively described. Only Thompson et al found a nonsense mutation in the tumor suppressor protein p16 INK4a , which encodes the cyclin-dependent kinase inhibitor (CDKN2A) in the gene [15].…”

Benign biliary neoplasms and biliary tumor precursors

“…Multiple clonal cytogenetic alterations have been described in BAF, supporting its neoplastic nature. Moreover, amplifications of CCND1 and ERBB2 and mutations in CDKN2A were found in cases showing aggressive behavior and malignant transformation 22 .…”

“…As the behavior of these tumors is poorly understood, patients require close clinical follow-up. Malignant degeneration leads to the development of a conventional adenocarcinoma 20 , 22-25 .…”

Malignant Transformation Arising Within Unusual and Rare Hepatic Lesions: Fibropolycystic Disease Form of Ductal Plate Malformation and Biliary Adenofibroma

“…Biliary adenofibroma is a rare primary hepatic tumor with less than 20 cases described since it was first described in 1993 by Tsui et al 19 These cases including ours (malefemale 9:11) are summarized in Table 1. [19][20][21][22][23][24][25][26][27][28][29][30][31] Most reported cases of BAF are solitary lesions, and only one female patient had multiple (3) lesions. 21 Location wise, of the 22 BAF lesions in these 20 patients, 10 were found in the left lobe (size: 1.7-16 cm), 11 were in the right lobe (size: 2.5-20 cm), and 1 was not specified.…”