Incidentally diagnosed peliosis hepatis mimicking hepatic adenoma: a rare case report and literature review

Abstract

Background:

Peliosis hepatis is a rare vascular disorder characterized by blood-filled cystic spaces within the hepatic parenchyma. It is often asymptomatic and may radiologically mimic hepatic adenoma or other hypervascular liver tumors, making preoperative diagnosis challenging.

Case report:

We report a 28-year-old female who presented with mild abdominal pain. An incidental liver mass was detected on ultrasound. Laboratory investigations were unremarkable. Contrast-enhanced computed tomography revealed a large hypervascular mass involving segments III and IV of the liver, suggestive of hepatic adenoma. The patient underwent a left lateral sectionectomy. Histopathological examination unexpectedly revealed peliosis hepatis.

Discussion:

Peliosis hepatis is an uncommon vascular abnormality of the liver that may mimic hypervascular hepatic tumors on imaging, making diagnosis challenging. Imaging findings are often nonspecific, and a definitive diagnosis usually requires histopathological examination. Although commonly associated with drugs or systemic diseases, idiopathic cases can occur. Surgical resection is often performed when malignancy cannot be excluded or when lesions are large.

Conclusion:

Peliosis hepatis should be considered in the differential diagnosis of hypervascular hepatic masses, especially when imaging findings are atypical. Definitive diagnosis often requires histopathological confirmation.

Introduction

Peliosis hepatis is an uncommon hepatic vascular condition characterized by multiple blood-filled cystic spaces within the hepatic parenchyma. The condition was first described by Zak in 1950 and remains poorly understood^[1^].

Several etiological factors have been reported, including anabolic steroid use, oral contraceptive use, immunosuppressive therapy, hematologic malignancies, and chronic infections such as tuberculosis. However, many cases remain idiopathic, with no identifiable cause^[2,3^].

HIGHLIGHTS

• Peliosis hepatis is a rare vascular liver disorder.

• Imaging may mimic hepatic adenoma or other hypervascular liver tumors.

• Large hypervascular liver mass detected incidentally on ultrasound.

• Surgical resection was performed due to the suspicion of a hepatic adenoma.

• Histopathology confirmed peliosis hepatis diagnosis.

Radiologically, peliosis hepatis may closely resemble hepatic adenoma, focal nodular hyperplasia (FNH), or hepatocellular carcinoma (HCC), which may lead to surgical intervention when malignancy cannot be excluded^[3^]. This case report has been presented in line with the SCARE checklist^[4^].

Case report

Case presentation

A 28-year-old female presented with mild, intermittent abdominal pain of 6 months’ duration. There was no history of weight loss, fever, jaundice, oral contraceptive use, steroid exposure, chronic liver disease, or other significant medical history.

Clinical findings

On physical examination, the patient had stable vital signs. There was no pallor or jaundice, no abdominal tenderness, and no hepatosplenomegaly or ascites.

Laboratory investigations, including complete blood count, coagulation profile, and liver function tests, were within normal limits. Viral hepatitis markers (heptatis B virus, hepattis C virus) were negative.

Ultrasound revealed an incidental hepatic mass during the evaluation of abdominal pain. Contrast-enhanced computed tomography (CT) demonstrated a well-demarcated 13 × 10 cm arterial-phase hyperenhancing mass involving segments III and IV of the liver (Fig. 1A). The lesion became isoattenuating relative to the background liver parenchyma on portal and delayed phases (Figs. 1B and 1C). No central scar or calcification was identified. There was no intrahepatic or extrahepatic biliary duct dilatation. Portal and hepatic veins were patent, with no filling defects. Other abdominal organs were unremarkable.

Figure 1B.

Portal venous phase contrast-enhanced abdominal CT scan. Axial image demonstrating a large heterogeneous lesion involving the left hepatic lobe measuring approximately 13 × 10 cm, with relative hypoattenuation compared to adjacent liver parenchyma.

Figure 1C.

Delayed phase contrast-enhanced abdominal CT scan. Axial image demonstrates a large, well-defined heterogeneous lesion involving the left hepatic lobe, measuring approximately 13 × 10 cm (as indicated). The lesion shows persistent hypoattenuation relative to the surrounding liver parenchyma, without a definite enhancing capsule.

Figure 1A.

Arterial phase contrast-enhanced CT scan of the abdomen. Demonstrating a large, well-defined heterogeneous lesion in the left hepatic lobe measuring approximately 13 × 10 cm (axial image), showing heterogeneous enhancement relative to the surrounding liver parenchyma.

Based on these findings, hepatic adenoma was considered the primary diagnosis, with FNH as a differential.

Therapeutic intervention

Given the large size (>5 cm), hypervascular nature, and inability to exclude an adenoma with malignant potential, the patient was counseled and scheduled for surgical resection.

Surgery was performed via a left extended subcostal incision under general anesthesia. Intraoperatively, an approximately 10 × 12 cm vascular mass was identified, replacing the left lateral segment of the liver, with no peritoneal deposits or ascites (Fig. 2). A left lateral sectionectomy was performed with parenchymal transection. The hepatic vein was identified and ligated intrahepatically, and hemostasis was secured. A subhepatic drain was placed, and the abdomen was closed in layers. The patient tolerated the procedure well and remained hemodynamically stable throughout.

Figure 2.

Intraoperative photograph demonstrating a large vascularized mass involving the left lateral segment of the liver prior to resection.

Microscopic examination revealed multiple irregular, blood-filled cystic spaces within the hepatic parenchyma, consistent with peliosis hepatis. These spaces lacked a true endothelial lining and were variably distributed, causing distortion of the hepatic architecture. Features were predominantly consistent with the parenchymal pattern, characterized by sinusoidal dilatation and hepatocellular plate disruption, rather than the phlebectatic type. No evidence of cellular atypia or malignancy was identified (Fig. 3). Immunohistochemistry was not performed.

Figure 3.

Histopathological section of the resected liver specimen (H&E stain, ×400) showing irregular blood-filled cystic spaces within hepatic parenchyma without true endothelial lining and atypical cells consistent with peliosis hepatis.

Follow-up and outcomes

The patient was discharged on postoperative day 5 after an uneventful recovery. Follow-up was smooth, with no reported complications.

Discussion

This report describes a 28-year-old female in whom a large hepatic mass was incidentally detected during evaluation for mild abdominal pain. Laboratory investigations were unremarkable. Contrast-enhanced CT imaging demonstrated a hypervascular lesion involving segments III and IV of the liver, initially suggestive of hepatic adenoma. Due to the lesion’s size and potential risk of hemorrhage, the patient underwent left lateral sectionectomy. Unexpectedly, histopathological examination revealed peliosis hepatis, characterized by multiple blood-filled cavities within the hepatic parenchyma without evidence of malignancy.

Peliosis hepatis is an uncommon vascular disorder characterized by blood-filled cavities within the hepatic parenchyma due to sinusoidal dilatation and microvascular disruption^[1,5^]. It is often asymptomatic and incidentally discovered during imaging studies, surgery, or autopsy^[2,6^].

The exact pathogenesis of peliosis hepatis remains unclear, but several mechanisms have been proposed. The most widely accepted theory suggests that damage to sinusoidal endothelial cells leads to dilation of hepatic sinusoids and the formation of blood-filled cavities^[2^].

Several risk factors and associated conditions have been reported in the literature. These include anabolic steroid use, oral contraceptive therapy, immunosuppressive medications such as azathioprine, chronic infections, hematologic malignancies, and solid organ transplantation^[2,3^]. However, 20–50% of cases occur without an identifiable underlying cause, and such cases are considered idiopathic^[3^].

The clinical presentation of peliosis hepatis is highly variable. Many patients are asymptomatic, while others may present with abdominal pain, hepatomegaly, portal hypertension, liver failure, or spontaneous hepatic rupture, which may be life-threatening^[2^].

Radiological diagnosis of peliosis hepatis remains challenging because imaging findings are nonspecific and frequently mimic hepatic malignancies or other benign liver tumors^[7^]. On contrast-enhanced CT, lesions may show arterial phase enhancement with variable washout patterns, which can resemble hepatic adenoma, FNH, HCC, metastases, or hepatic abscesses^[6,7^]. Advanced imaging modalities such as magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography/CT may help characterize these lesions but often cannot definitively differentiate peliosis hepatis from malignant hepatic tumors. Because of these diagnostic limitations, histopathological examination remains the gold standard for diagnosis^[6–8^].

Microscopically, peliosis hepatis is characterized by irregular blood-filled spaces within the hepatic parenchyma, sometimes lacking an endothelial lining and surrounded by hepatocytes. Immunohistochemical staining (e.g., CD31, CD34, and reticulin) may assist in highlighting the absence of a true endothelial lining and excluding other vascular tumors; however, in this case, immunohistochemistry was not performed^[9^].

Management of peliosis hepatis depends on the underlying cause and the severity of the disease. In many cases, treatment involves the removal of the causative agent or the management of associated conditions^[3^]. However, surgical resection may be necessary when the lesion presents as a solitary mass, when malignancy cannot be excluded, or when complications such as hemorrhage occur^[7^]. In this case, the surgery was performed based on the current guidelines, including those from the American College of Gastroenterology and the European Association for the Study of the Liver, which recommend surgical resection of hepatic adenomas ≥5 cm in diameter, particularly when lesions persist or grow after risk factor modification, due to the increased risk of hemorrhage and malignant transformation^[10,11^].

This case highlights that peliosis hepatis, although uncommon, should be considered in the differential diagnosis of hypervascular hepatic lesions, particularly when imaging findings are not typical for common entities such as hepatic adenoma or FNH. It emphasizes that radiological features alone may be insufficient for definitive diagnosis, especially in large solitary lesions. Based on this experience, a more cautious and stepwise diagnostic approach may be adopted in future cases. This could include closer correlation of imaging findings with clinical history and risk factors, as well as consideration of advanced imaging modalities or image-guided biopsy in selected patients where the diagnosis remains uncertain. Such an approach may help avoid unnecessary surgical intervention when an asymptomatic small benign condition is suspected.

Overall, this case underscores the importance of maintaining a broad differential diagnosis and highlights the essential role of histopathological confirmation in guiding appropriate management.

Strengths and limitations

This case highlights a rare hepatic vascular condition presenting as a large hypervascular mass mimicking hepatic adenoma, emphasizing the diagnostic challenge and the importance of clinicoradiological and pathological correlation. A key strength is the definitive diagnosis established by histopathology following surgical resection. The case also has multidisciplinary relevance, underscoring the roles of radiologists in imaging interpretation, surgeons in management decision-making, and pathologists in confirming the diagnosis. This shows the importance of a collaborative approach in evaluating complex hepatic masses.

Limitations include the inability to establish a preoperative diagnosis, the lack of hepatobiliary MRI, and the absence of immunohistochemical analysis, which may have provided additional diagnostic detail.

Ethical approval

Ethical approval was not required in accordance with institutional policy for case reports. Written informed consent was obtained from the patient for publication.

Consent

Informed written consent was obtained from the patient for the publication of this case report and the accompanying images.

Sources of funding

No funding was received.

Author Contributions

Conception and design: M.T.G., H.S.K., and F.H.G. Writing the article: M.T.G. Critical revision of the article: M.T.G., H.S.K., and F.H.G. Final approval of the article: M.T.G., H.S.K., and F.H.G.

Conflicts of interest disclosure

The authors report no conflicts of interest in this work.

Research registration unique identifying number (UIN)

Not applicable.

Guarantor

Mulugeta Taeme Gebretsion.

Provenance and peer review

Not commissioned, externally peer-reviewed.

Data availability statement

Data supporting the findings of this case report are included within the article. Additional details are available from the corresponding author upon reasonable request, subject to patient confidentiality considerations.

Assistance with the study

None.