Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.
Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada.
Am J Surg Pathol. 2021 Aug 1;45(8):1098-1107. doi: 10.1097/PAS.0000000000001711.
Myxoid hepatic adenomas are a rare subtype of hepatic adenomas with distinctive deposition of extracellular myxoid material between the hepatic plates. A total of 9 cases were identified in 6 women and 3 men with an average of 59±12 years. The myxoid adenomas were single tumors in 5 cases and multiple in 4 cases. In 1 case with multiple adenomas, the myxoid adenoma arose in the background of GNAS-mutated hepatic adenomatosis. Myxoid hepatic adenomas had a high frequency of malignant transformation (N=5 cases). They were characterized at the molecular level by HNF1A inactivating mutations, leading to loss of LFABP protein expression. In addition, myxoid adenomas had recurrent mutations in genes within the protein kinase A (PKA) pathway or in genes that regulate the PKA pathway: GNAS, CDKN1B (encodes p27), and RNF123. In sum, myxoid adenomas are rare, occur in older-aged persons, have a high risk of malignant transformation, and are characterized by the combined inactivation of HNF1A and additional mutations that appear to cluster in the PKA pathway.
黏液性肝细胞腺瘤是肝细胞腺瘤的一种罕见亚型，其特征是在肝板之间有独特的细胞外黏液样物质沉积。在 6 名女性和 3 名男性中总共发现了 9 例，平均年龄为 59±12 岁。黏液性腺瘤在 5 例中为单发肿瘤，在 4 例中为多发肿瘤。在 1 例多发性腺瘤中，黏液性腺瘤发生在 GNAS 突变性肝细胞腺瘤病的背景下。黏液性肝细胞腺瘤恶性转化的频率很高（N=5 例）。在分子水平上，它们表现为 HNF1A 失活突变，导致 LFABP 蛋白表达缺失。此外，黏液性腺瘤还存在蛋白激酶 A（PKA）途径内基因或调节 PKA 途径的基因的反复突变：GNAS、CDKN1B（编码 p27）和 RNF123。总之，黏液性腺瘤罕见，发生于老年患者，恶性转化风险高，其特征是 HNF1A 的联合失活以及似乎聚集在 PKA 途径中的其他突变。
