Laparoscopic partial hepatectomy for primary hepatic PEComa: a case report

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors composed of cells exhibiting an epithelioid morphology. These cells typically arrange around small blood vessels (perivascular spaces) and display dual differentiation characteristics of smooth muscle cells and melanocytes. Diagnosis is challenging due to the absence of specific symptoms or tumor markers. This case features a young male patient with a large hepatic PEComa, whose imaging findings resemble those of hepatocellular carcinoma. We have detailed the entire process from diagnosis to treatment to aid in differential diagnosis and surgical planning.

A 31-year-old male patient with no prior medical history underwent a routine health examination 20 days prior to presentation. Although the patient was asymptomatic, ultrasound revealed an incidental hepatic lesion measuring 58 × 50 × 45 mm (maximum diameter 58 mm, or 5.8 cm). The screening center suspected a hemangioma. Subsequently, he presented to our hospital. Comprehensive imaging studies, including ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), revealed a 58 mm-diameter space-occupying lesion in segments V and VIII of the right hepatic lobe. Imaging findings initially raised suspicion for hepatocellular carcinoma. To minimize surgical trauma and preserve liver function, our team discussed surgical approaches and ultimately decided on a laparoscopic partial hepatectomy. During the procedure, we obtained a specimen for pathological examination. The final histopathological analysis confirmed the diagnosis of a PEComa with undetermined malignant potential. The patient recovered smoothly postoperatively and was successfully discharged.

PEComa has an insidious onset and is rare. Early diagnosis is often challenging, and imaging studies typically show no highly specific findings. Clinical diagnosis frequently relies on biopsy. In terms of treatment, radical resection (R0 resection, i.e., negative margins) represents the definitive therapeutic approach.