Case Report
In 2019, a 70-year-old woman visited her local doctor with a complaint
of weight loss of 15 kg in a month. Abdominal ultrasound revealed a
liver tumor, and she was referred to our hospital. There was no history
of alcohol intake. Blood examination (Table 1) showed aspartate
aminotransferase elevation (AST; 66 U/L), alanine aminotransferase
elevation (ALT; 68 U/L), positive HBs antigen, HBV-DNA elevation (5.6
LogIU/mL), and negative hepatitis C virus antibody. Alfa-fetoprotein
(AFP) was markedly elevated (3946 ng/mL). Abdominal ultrasound revealed
a 22 x 20 mm mass with an internal mosaic pattern in segment 5 of the
liver (Figure 1). Angiographic computed tomography (AGCT) scan revealed
low absorption in CT during arterioportography (CTAP) and uniformly high
absorption in both early and delayed CT during hepatic arteriography
(CTHA) (Figure 2). EOB-MRI revealed a high signal in early phase, low
signal in hepatocellular phase, high signal in diffusion-weighted image,
and low signal in ADC (Figure 3). The lesion was solitary and there were
no findings suggestive of vascular invasion. Laparoscopic partial
hepatectomy was performed subsequent to the diagnosis of classical
hepatocellular carcinoma (HCC) UICC Stage Ib. Microscopically, there
were many infiltrating lymphocytes in the background, and tumor cells
with round to oval nuclei with prominent irregularities and abundant
eosinophilic sporophytes had grown in a plump, sheet-like pattern. Some
tubular structures corresponding to the moderately differentiated type
remained at the tumor margins; however, the majority of the cells were
the poorly differentiated type (Figure 4). Immunostaining of the tumor
cells was positive for glypian3 and negative for EBER. Programmed cell
death ligand 1 (PD-L1) was positive in about 40% of tumor cells, and
inflammatory cells around the tumor were also partially positive,
showing scattered positive cells in the form of small clusters. The
infiltrating lymphocytes showed a mixture of CD3- and CD8- positive
cytotoxic T cells and CD4- and FOXP3-positive regulatory T cells (Figure
5-8). Twenty months have passed since hepatectomy and no recurrence has
been observed to date.