Rapidly enlarged inflammatory hepatocellular adenoma: A case report

We present a rare case of rapidly enlarging inflamematory hepatocellular adenoma (IHCA) in a 60-yearold Japanese man. Screening abdominal computed tomography (CT) for the fatty liver patient revealed a 1.7-cm liver mass in the anterior segment of the liver. After 19 months, the lesion had rapidly enlarged to 6 cm in diameter and the patient was referred to our hospital. On perflubutane microbubble contrast-enhanced ultrasonography, the tumor showed a characteristic centripetal filling pattern in the vascular phase. We performed hepatic anterior segment resection because we could not rule out malignant tumor. Histopathological examination showed hyperplasia of mildly atypical hepatocytes and sinusoidal dilatation with marked inflammatory cell infiltration. Immunohistological staining revealed positive staining for serum amyloid A and C-reactive protein; therefore, we diagnosed this tumor as IHCA. The patient remains alive 42 months after operation without evidence of recurrence.