Published online Sep 21, 2021. doi: 10.3748/wjg.v27.i35.5967
Peer-review started: March 29, 2021
First decision: May 28, 2021
Revised: May 29, 2021
Accepted: August 13, 2021
Article in press: August 13, 2021
Published online: September 21, 2021
Perivascular epithelioid cell tumor (PEComa) is an uncommon tumor of mesenchymal origin. Cases of PEComa in the liver are extremely rare.
Cases of PEComa in the liver are extremely rare, and surgical resection currently is the most effective therapeutic strategy to cure patients or prolong the survival period. In this study, the clinical and pathological features, immunohistochemical phenotypes, and information on treatment modalities of 26 cases of hepatic PEComa were collected, and the effects of different surgical methods on prognosis were evaluated to provide information for the guidance of clinical treatment.
We aimed to analyze the clinicopathological features and treatment of hepatic PEComa and to evaluate the prognosis after different treatments.
Clinical and pathological data of 26 patients with hepatic PEComa were collected. All cases were analyzed by immunohistochemistry and clinical follow-up.
This study included 17 females and 9 males, with a median age of 50 years. Lesions were located in the left hepatic lobe in 13 cases, in the right lobe in 11, and in the caudate lobe in 2. The median tumor diameter was 6.5 cm. Light microscopy revealed that the tumor cells were mainly composed of epithelioid cells. The cytoplasm contained heterogeneous eosinophilic granules. There were thick-walled blood vessels, around which tumor cells were radially arranged. Immunohistochemical analysis of pigment-derived and myogenic markers in PEComa tumors revealed that 25 cases were HMB45 (+), 23 were Melan-A (+), and 22 SMA (+). TFE3 and Desmin were negative in all cases. All the FISH samples were negative for TFE3 gene break-apart probe. Tumor tissues were collected by extended hepatic lobe resection or simple hepatic tumor resection as the main treatments. Median follow-up was 62.5 mo. None of the patients had metastasis or recurrence, and there were no deaths due to the disease.
Hepatic PEComa is a rare mesenchymal tumor that exhibits an inert biological behavior, and its diagnosis, treatment, and follow-up are challenging. Our study of 26 cases of hepatic PEComa revealed that there was no difference in the prognosis between simple resection of liver tumor and extended resection of liver lobe. Optimal surgical resection currently is the best treatment option, and radiotherapy, chemotherapy, and immunotherapy may become more effective in future.
The number of cases in the current retrospective study was limited by the rarity of hepatic PEComa. Therefore, further multicenter, larger-cohort studies are warranted to investigate the clinicopathological features and biological behavior of hepatic PEComa.