A 58-year-old woman was admitted to a hospital with pain in the upper right abdomen lasting for over 3 months. Laboratory tests for liver function and tumor markers were unremarkable. Contrast-enhanced computed tomography showed a 1.6 cm × 1.3 cm tumor on the arterial phase (Figure 1A). The mass seemed to be hepatocellular carcinoma, so the patient underwent partial hepatectomy (Figure 1B). Postoperative examination showed that the tumor consisted of thick-walled blood vessels and epithelioid myocytes, with no fatty component (Figure 1C and 1D). Further examination revealed positive immunostaining for melanocytic human melanin black-45 (HMB-45), desmin, and smooth muscle actin (Figure 1E–1G). Besides, Ki-67 immunohistochemical labeling index was about 1% to 2% (Figure 1H). These results confirmed that the patient had hepatic perivascular epithelioid cell neoplasm (PEComa). Five days after the surgery, the patient was discharged home, and regular follow-up examinations for 36 months have so far revealed no recurrence of hepatic PEComa.
The World Health Organization defines PEComa a rare disease in the form of “a mesenchymal tumor composed of histologically and immunohistochemically distinct perivascular epithelioid cells.”1 Hepatic PEComas have been described in only a few dozen cases, and are usually diagnosed incidentally.2 However, due to a lack of specificity in clinical presentation, laboratory tests, and imaging examinations, it is difficult to preoperatively distinguish hepatic PEComa from other types of liver tumors. The diagnosis of hepatic PEComa depends on histologic confirmation, in which immunohistochemical detection of HMB-45, melanoma antigen, and smooth muscle markers (actin and desmin) is characteristic and decisive.2
Surgical resection is a gold standard for treatment of hepatic PEComa,3 especially for patients who meet 2 or more of the following criteria: 1) tumor size above 5 cm, 2) infiltrative margins, 3) high-grade nuclear atypia, 4) mitotic count above 1/50 high-power fields, 5) hypercellularity, 6) vascular invasion, and 7) necrosis.4 Although most reported cases have a benign course, some are aggressive with locoregional recurrences and distant metastases.5 Therefore, long-term periodic follow-up is necessary.
Hu Tian, MD, Department of General Surgery, The First Affiliated Hospital of Shandong First Medical University and Shandong Provincial Qianfoshan Hospital, 16766 Jingshi Road, Jinan, Shandong, China, phone: +86 0531 82968900, email: tianhu6585@163.com
October 13, 2023.
November 22, 2023.
November 27, 2023.
The authors thank the patient and her family, and all the clinical technicians for their support for this study.
This study was funded by Jinan Science and Technology Bureau (202225060; to HT).
None declared.
Liu X-L, Cui J, Tian H. Hepatic perivascular epithelioid cell neoplasm in a 58-year-old woman. Pol Arch Intern Med. 2024; 134: 16615. doi:10.20452/pamw.16615
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