Contributed by Eizaburo Sasatomi MD, PhD and Anthony J Demetris, MD
Published on line in November 2005
The patient was a 48-year-old woman with a one-year history of back pain, who recently developed right upper quadrant pain that radiated to her side and back. The past medical history included cervical cancer in 1983, bipolar disorder, fibromyalgia, and Hashimoto's thyroiditis. Medications at presentation listed Synthroid, lithium, and Aviane (ethinyl estradiol and levonorgestrel). She had been on birth control pills for the past 20 years.
On physical examination, there was mild upper right quadrant tenderness to palpation over the liver edge. The remaining physical examination and review of systems were unremarkable. Her liver injury tests showed an ALT of 50 IU/L, AST of 45 IU/L, GGTP of 250 IU/L, and total bilirubin of 0.4 mg/dL. Abdominal computed tomography revealed a large isodense mass replacing the right lobe of the liver (Figure 1, left). A contrast enhanced scan revealed that the mass was hypervascular with large feeding arteries and large veins (Figure 1, right). Two smaller hypervascular lesions were also present in the lateral and medial segments. The patient underwent right hepatic lobectomy with an excisional biopsy of the left lobe liver lesion.
The capsular surface of the right lobectomy specimen of the liver showed an area of lighter brown discoloration compared to the adjacent dark red-brown normal-appearing liver (Figure 2). Sectioning revealed an irregularly lobulated, but well circumscribed, light-brown to orange-brown bulging mass, 15.0 x 11.0 x 6.0 cm, occupying about 65% of the right lobe (Figure 3). The mass was vaguely nodular, but showed no gross evidence of necrosis or hemorrhage. No central scar was recognized. Another separate circumscribed mass, 1.5 x 2.0 x 0.9 cm, was similar in appearance. The background liver was red-brown and grossly unremarkable. A third small lesion (1.8 x 1.0 x 0.7 cm) was also resected from segment II; the appearance was similar to the other two right lobe lesions.
Histologic sampling of the large mass revealed an un-encapsulated vaguely nodular arrangement of hepatocytes (Figure 4), but no normal hepatic architecture. The lesion lacked portal tracts and terminal hepatic veins. Instead, the parenchyma consisting of hepatic nodules was traversed by variously-sized, thick-walled vessels (Figure 5), as well as thin to thick fibrous septa that also contained similar abnormal vessels (Figures 6, 7 and 8) and lymphoplasmacytic inflammation (Figure 9). The interface zone between the fibrous septae and hepatocyte nodules showed a prominent ductular reaction that varied from area to area. The parenchymal component consisted of compactly arranged trabeculae of hepatocytes, which had round normochromatic nuclei and slightly larger and paler cytoplasm, compared to the adjacent non-lesional liver parenchyma (Figures 4 and 10). The smaller nodule within the right lobe showed histologic features similar to the larger lesion, but it lacked thick fibrous septa. The small lesion from segment II of the left lobe showed indistinct nodularity, a few large portal tracts, and some aberrant vascularity including occasional arteries unaccompanied by other portal tract structures and dilated venules. Although not well defined, this lesion was interpreted to represent an earlier stage of the other two lesions.