Perivascular epithelioid cell tumors of the liver misdiagnosed as hepatocellular carcinoma:Three case reports

BACKGROUND Hepatic perivascular epithelioid cell neoplasms(PEComas)are rare.Diagnostic and treatment experience with hepatic PEComa remains insufficient.CASE SUMMARY Three hepatic PEComa cases are reported in this paper:One case of primary malignant hepatic PEComa,one case of benign hepatic PEComa,and one case of hepatic PEComa with an ovarian mature cystic teratoma.During preoperative imaging and pathological assessment of intraoperative frozen samples,patients were diagnosed with hepatocellular carcinoma(HCC),while postoperative pathology and immunohistochemistry subsequently revealed hepatic PEComa.Patients with hepatic PEComa which is misdiagnosed as HCC often require a wider surgical resection.It is easy to mistake them for distant metastases of hepatic PEComa and misdiagnosed as HCC,especially when it’s combined with tumors in other organs.Three patients eventually underwent partial hepatectomy.After 1-4 years of follow-up,none of the patients experienced recurrence or metastases.CONCLUSION A clear preoperative diagnosis of hepatic PEComa can reduce the scope of resection and prevent unnecessary injuries during surgery.

Retroperitoneal neoplasm with perivascular epithelioid cell differentiation: A case report and review of literature

The retroperitoneal neoplasm with perivascular epithelioid cell differentiation (PEComa) is an extremely rare pathological entity. In this article, we reported one case of a 45-year-old woman who was admitted to our hospital (The Second People's Hospital of Hefei, China) for retroperitoneal neoplasm with perivascular epithelioid cell differentiation. The B ultrasonic examination showed echopoor in the region of cavitas pelvis. The histologic characteristics and immunohistochemical phenotype both revealed the neoplasm with perivascular epithelioid cell differentiation.

Single-center Experience in the Diagnosis and Treatment of Hepatic Perivascular Epithelioid Cell Neoplasm

Background and Aims:Perivascular epithelioid cell neo-plasms(PEComas)are a rare type of mesenchymal neo-plasm and their preoperative diagnosis is challenging.In this study,we summarized the experience from a single medical center to study the examinations,clinical presen-tations,and pathological and histological characteristics of PEComas in the liver in order to optimize overall un-derstanding of the diagnosis and treatment of these neo-plasms.Methods:We conducted a retrospective analysis to investigate the clinical and pathological characteristics as well as imaging presentations of 75 patients diagnosed with hepatic PEComa in The First Affiliated Hospital of Zhe-jiang University between April 2010 and April 2020.Re-sults:Among the 75 patients,52 were women,and the median age was 48 years.Most patients had no specific symptoms,and two were admitted to the hospital for a second time owing to relapse.All patients underwent surgi-cal resection.Histologically,38 patients had classical angio-myolipoma(AML)and 37 had epithelioid AML.The PECo-mas were accompanied by positive immunohistochemical expression of HMB45,Melan-A,and smooth muscle actin.Follow-up data were obtained from 47 of the total 75 pa-tients,through October 2020.Two patients had metastasis after surgery.Conclusions:AML is the most common type of hepatic PEComa.There are no specific symptoms of he-patic PEComa,and serological examinations and imaging modalities for accurate preoperative diagnosis are lacking.Epithelioid AML should be considered a tumor of uncertain malignant potential;however,the prognosis of PEComa af-ter resection is promising.