Case report

A 41-year-old woman with long-term oral contraceptive use and no significant medical or surgical history presented with abrupt right upper quadrant pain immediately after vigorous physical exertion. She denied fever or jaundice. On admission, she was hemodynamically stable. Abdominal examination revealed right upper quadrant tenderness without signs of peritoneal irritation.

Initial laboratory tests showed anemia, with a hemoglobin level of 7.7 g/dL, and mild elevation of liver enzymes (AST, 62 U/L; ALT, 58 U/L).

Abdominal ultrasound demonstrated heterogeneous hepatic lesions containing internal echogenic components suggestive of hemorrhage, together with a small amount of perihepatic free fluid.

Unenhanced CT demonstrated multiple distinct hemorrhagic hepatocellular adenomas. The 2 largest lesions were a 12-cm lesion involving segments VII and VIII (Fig. 1) and a separate 3-cm lesion in segment V (Fig. 2). Both lesions contained spontaneously hyperattenuating areas consistent with intralesional hemorrhage. The larger lesion extended to the subcapsular region and was associated with a subcapsular hematoma.

Fig. 1: Unenhanced CT appearance of the largest hemorrhagic hepatocellular adenoma. (A and B) Axial and coronal unenhanced CT images showing a 12-cm heterogeneous, spontaneously hyperattenuating lesion involving segments VII and VIII, consistent with extensive intralesional hemorrhage (red arrow). The lesion has a subcapsular component with an associated subcapsular hematoma and causes focal bulging of the hepatic capsule (white arrow).

Fig. 2: Unenhanced CT demonstrating a second distinct hemorrhagic hepatocellular adenoma in segment V. Axial unenhanced CT image showing a separate 3-cm lesion in hepatic segment V, containing spontaneously hyperattenuating areas consistent with intralesional hemorrhage (red arrowhead). This second distinct lesion confirms the multifocal nature of the hepatocellular adenomas.

On contrast-enhanced CT, the larger lesion and the associated subcapsular hematoma remained hypoattenuating relative to the surrounding liver parenchyma, without appreciable enhancement or definite active contrast extravasation (Fig. 3). No portal vein thrombosis or biliary dilatation was identified.

Fig. 3: Contrast-enhanced CT appearance of the largest hemorrhagic hepatocellular adenoma. (A and B) Arterial and portal-phase contrast-enhanced CT images showing the large hemorrhagic lesion involving segments VII and VIII (red arrow) and the associated subcapsular hematoma (white arrow). The lesion and hematoma remain hypoattenuating relative to the surrounding liver parenchyma, without appreciable enhancement or definite active contrast extravasation.

MRI was subsequently performed and confirmed the presence of multiple hemorrhagic hepatocellular adenomas. The largest lesion demonstrated heterogeneous predominantly isointense signal on T1-weighted imaging and heterogeneous hyperintense signal on T2-weighted imaging, consistent with intralesional blood products. Coronal imaging confirmed its subcapsular component and associated hematoma and also demonstrated the separate 3-cm lesion in segment V with similar hemorrhagic imaging features, thereby confirming the multifocal nature of the disease (Fig. 4). On dynamic postcontrast MRI, viable portions of both the large lesion and the segment V lesion showed heterogeneous arterial enhancement (Fig. 5).

Fig. 4: MRI appearance of multiple intrahepatic and subcapsular lesions. (A–C) MRI showing multiple intrahepatic lesions and an associated subcapsular hematoma. The largest lesion demonstrates heterogeneous predominantly isointense signal on T1-weighted imaging (green arrow) (A) and heterogeneous hyperintense signal on T2-weighted imaging (yellow arrow) (B). The coronal image (C) confirms its subcapsular component and demonstrates a separate smaller lesion in segment V (red arrowhead) with similar hemorrhagic imaging features, thereby confirming the multifocal nature of the disease.

Fig. 5: Dynamic MRI demonstrating arterial enhancement in 2 distinct hepatocellular adenomas. (A) Arterial-phase MRI showing heterogeneous enhancement within the viable components of the large hemorrhagic adenoma involving segments VII and VIII (white arrowhead). (B) Arterial-phase MRI demonstrating similar enhancement within the separate 3-cm adenoma located in segment V (black arrow).

During clinical monitoring after completion of the imaging assessment, serial laboratory tests demonstrated a further decline in hemoglobin level, accompanied by worsening right upper quadrant pain. Given the ongoing clinical and biological suspicion of continued or intermittent bleeding, selective arterial embolization was performed despite the absence of definite active contrast extravasation on CT. The procedure resulted in clinical improvement and stabilization of the hemoglobin level.

After selective arterial embolization and clinical and biological stabilization, tissue sampling of the larger lesion was performed. Histopathological examination confirmed an inflammatory hepatocellular adenoma with extensive hemorrhagic changes (Fig. 6).

Fig. 6: Histopathological features of ruptured inflammatory hepatic adenoma. Microscopic examination (H&E stain) shows dilated sinusoidal vascular channels with areas of intralesional hemorrhage and inflammatory stroma, consistent with an inflammatory subtype of hepatocellular adenoma complicated by rupture.

The patient recovered uneventfully. At 3-month follow-up, CT showed regression of the embolized lesion and resolution of the subcapsular hematoma, with complete resolution of symptoms.