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.

中文翻译：

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粘液样肝腺瘤的形态学和分子发现。

粘液样肝腺瘤是肝腺瘤的一种罕见亚型，在肝板之间具有独特的细胞外粘液样物质沉积。共确诊9例，其中女性6例，男性3例，平均年龄59±12岁。粘液样腺瘤单发5例，多发4例。在 1 例多发性腺瘤病例中，粘液样腺瘤是在 GNAS 突变的肝腺瘤病背景下出现的。粘液样肝腺瘤恶变频率较高（N=5例）。它们在分子水平上表现为 HNF1A 失活突变，导致 LFABP 蛋白表达丧失。此外，粘液样腺瘤的蛋白激酶 A (PKA) 通路内的基因或调节 PKA 通路的基因中存在反复突变：GNAS、CDKN1B（编码 p27）和 RNF123。总之，粘液样腺瘤很罕见，发生在老年人中，具有很高的恶变风险，其特征是 HNF1A 的联合失活和似乎聚集在 PKA 途径中的其他突变。