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Published on: May 9, 2025
Perivascular epithelioid cell tumor (PEComa) of the liver diagnosed by contrast-enhanced ultrasonography
Reiko Akitake1, Hiroyuki Kimura, Satoru Sekoguchi
1Division of Gastroenterology, Kyoto First Red Cross Hospital, Kyoto.
Abstract:
Perivascular epithelioid cell (PEC) is a unique cell which expresses both myogenic and melanocytic markers, and forms PEComa. A 36-year-old woman presented with a 35 mm-diameter liver tumor. MRI showed poor fat component in the tumor. Contrast-enhanced ultrasonography using the newly developed enhancing reagent, Sonazoid, clearly demonstrated early-phase enhancement of the tumor and rapid drainage of the reagent to veins, suggesting a PEComa. Lateral segmentectomy of the liver was performed. Histologically, epithelioid tumor cells around the vessels were immunostained with both HMB-45 and alpha-smooth muscle actin, confirming the diagnosis of PEComa. No recurrence has been found for 18 months following the operation.
Insights
Perivascular epithelioid cell (PEC) tumors, or PEComas, are rare. This case highlights the diagnostic utility of Sonazoid-enhanced ultrasonography in identifying a liver PEComa, confirmed by histology.
Area of Science:
- Oncology
- Pathology
- Radiology
Background:
- Perivascular epithelioid cell (PEC) tumors, known as PEComas, are rare mesenchymal neoplasms characterized by a unique phenotype expressing both myogenic and melanocytic markers.
- PEComas can arise in various locations, with the liver being an uncommon site.
Observation:
- A 36-year-old woman presented with a 35 mm liver tumor with a poor fat component on MRI.
- Contrast-enhanced ultrasonography (CEUS) with Sonazoid revealed characteristic early-phase enhancement and rapid venous drainage, suggesting a PEComa.
- Surgical resection via lateral segmentectomy was performed.
Findings:
- Histopathological examination confirmed epithelioid tumor cells arranged around vessels.
- Immunohistochemical staining revealed co-expression of HMB-45 (melanocytic marker) and alpha-smooth muscle actin (myogenic marker), confirming the diagnosis of PEComa.
- The patient remained recurrence-free for 18 months post-surgery.
Implications:
- This case underscores the value of advanced imaging techniques like Sonazoid-enhanced CEUS in the preoperative diagnosis of liver PEComas.
- Accurate diagnosis is crucial for appropriate surgical management and patient follow-up.
- The favorable outcome highlights the potential for successful treatment of liver PEComas with surgical resection.
