Hepatocellular adenoma Chapter 13 Hepatic Tumors, Benign 1 Hepatocellular adenoma Case 13.1

Clinical Presentation 13 Hepatic Tumors, Benign 2 Clinical Presentation A 30-year-old woman was admitted for evaluation of right upper quadrant pain that at times was severe. She had a 25 lb weight loss from a diet (“Weight Watchers”) and had been on oral contraceptives for the past 12 years.

Laboratory Values Course in Hospital LDH: 365 (NI 52-149) AST: 35 13 Hepatic Tumors, Benign 3 Laboratory Values LDH: 365 (NI 52-149) α-Fetoprotein: 5.0 (normal range) HBsAg: Negative AST: 35 ALT: 22 Alk Phos: 101 Course in Hospital Further workup led to an exploratory laparotomy revealing a large mass in the right hepatic lobe that was resected.

Pathology 13 4 Hepatic Tumors, Benign The tumor measured 13 × 6 × 5 cm and was multilobulated and gray-tan with focal areas of hemorrhage. The entire tumor was composed of cytologically benign hepatocytes forming trabecular cords one to two cells thick (a, b). Figure 13.1(a)

13 Hepatic Tumors, Benign 5 Pathology Figure 13.2(b)

13 Hepatic Tumors, Benign 6 Diagnosis Hepatocellular adenoma

13 Hepatic Tumors, Benign 7 Comment Although no genotyping was performed, this tumor best fits the hepatocyte nuclear factor 1α (HNF1α)-inactivated variant of hepatocellular adenomas, although usually that variant has some degree of steatosis as well (see Chapter 13, Table 13.2, Genotypic and phenotypic classification of hepatocellular adenomas). Importantly, although complications such as abdominal pain, tumor necrosis, and tumor rupture may still occur, malignant transformation is not a feature of this subtype.