Perivascular epithelioid cell tumor of the uterine cervix identified on the liquid-based cytology: a case report

Background: Perivascular epithelioid cell tumours (PEComa) occurring in the female genital tract are rare, typically found in the uterine corpus. PEComa occurring in the cervix are extremely rare, and very few cases have been reported till now.Cytological diagnosis of cervical PEComa is even rarer. So far, only two cases of PEComa diagnosed by conventional cervical smears have been reported. Case presentation: A 55-year-old postmenopausal women presented with abnormal vagina discharges for three months. Then, a liquid-based cytology test was performed. Microscopically, some loosely cohesive epithelioid cells were uniform with abundant clear cytoplasm, showed predominantly round or oval nuclei with finely stippled chromatin, and distinct round nucleoli were visible in some cells, notably with numerous melanin pigments in the cytoplasm. The cytopathological features were well correlated with cell blocks and histopathological findings. Upon immunohistochemistry, the tumor cells were positive for HMB45, TFE3, focally positive for MelanA, while negative for muscle marker. Fluorescence in situ hybridization (FISH) confirmed TFE3 gene rearrangement. The final pathological diagnosis was PEComa identified by the liquid-based cytology, cell blocks, immunohistochemistry and FISH. The patient underwent a total hysterectomy with bilateral salpingo-oophorectomy and was followed up for two years with no evidence of disease. Conclusion: The cytologic characteristics of the tumor may provide sufficient clues for diagnosing a PEComa, including loosely cohesive, epithelioid morphology with abundant clear cytoplasm or eosinophilic cytoplasm, low-grade nuclear atypia, cytoplasmic melanin pigment. That will help cytopathologists recognize this rare tumor that occurred in the cervix, combined with results of other detection methods, can achieve the definitive diagnosis of PEComa.