Perivascular epithelioid cell tumor of the uterine cervix identified on a conventional cervical smear

A Case Report of Malignant Perivascular Epithelioid Cell Tumors of the Uterus and Literature Review

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors originating from perivascular epithelioid cells. In gynecological system, the uterus is one of the most common sites affected by PEComas. Most PEComas are benign, and patients usually have a good prognosis. However, malignant uterus PEComa is rare, and better comprehensive epidemiological investigations are needed. To date, there are a few reported cases of uterus PEComa. We herein report a rare case of malignant PEComa occurred in the uterine corpus and cervix, possibly accompanied by pulmonary lymphangioleiomyomatosis (PLAM). In addition, 55 cases of malignant uterus PEComa were picked out and collected in the data base of PubMed and Medline. On the one hand, the age of onset, population distribution, clinical manifestations, metastatic sites and routes of metastasis were analysed. On the other hand, a summary of the epidemiology, pathogenesis, diagnosis, and treatments of uterus PEComa was given.

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

BACKGROUND

Perivascular epithelioid cell tumor (PEComa) occurring in the female genital tract are rare, and typically found in the uterine corpus. PEComa occurring in the cervix is 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 woman presented with abnormal vagina discharge for 3 months. A liquid-based cytology test was performed. Microscopically, some loosely cohesive epithelioid cells were uniform with abundant clear cytoplasm, showing predominantly round or oval nuclei with finely stippled chromatin. Distinct round nucleoli were visible in some cells, notably with numerous melanin pigments in the cytoplasm. The cytopathological features were well correlated with cell block and histopathological findings. Upon immunohistochemistry (IHC), the tumor cells were positive for HMB45 and 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 block, cervical biopsy, IHC and FISH result. The patient underwent a total hysterectomy with bilateral salpingo-oophorectomy and was followed up for 2 years with no evidence of disease.

CONCLUSION

The cytologic characteristics of the tumor can provide sufficient clues for PEComa diagnosis, which includes loosely cohesive, epithelioid morphology with abundant clear or eosinophilic cytoplasm, low-grade nuclear atypia, cytoplasmic melanin pigments. This will help cytopathologists to recognize this rare tumor that occurred in the cervix, and the combination of predictive morphology evaluation, immunophenotype, and molecular testing can achieve the definitive diagnosis of PEComa.

Perivascular epithelioid cell tumors (PEComa) of the gynecologic tract

PEComas of the female genital tract are rare mesenchymal neoplasms that are most common in the uterus, but also may occur in other gynecologic locations. As they morphologically and immunohistochemically resemble smooth muscle tumors, distinction between the two entities is often challenging, and may be aided by molecular analysis. Thus far, two distinct molecular groups-classic PEComas with TSC mutations and TFE3-translocation associated PEComas with TFE3 fusions have been described. Recognition of the first group is imperative as these patients may benefit from targeted therapy with mTOR inhibitors, if malignant. This review will focus on recognition of the morphologic and immunophenotypic features of PEComas, as well as the role of molecular testing in their diagnosis and treatment, analysis of the different algorithms to predict behavior, and differential diagnosis.

Malignant perivascular epithelioid cell tumor in the female genital tract: Preferred reporting items for systematic reviews and meta-analyses

BACKGROUND

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal tumor, located at various anatomic sites, including the female genital tract. This study aimed to evaluate the clinicopathological characteristics of patients with PEComa arising from the female genital tract.

METHODS

A retrospective study was conducted in Taipei Veterans General Hospital (Taipei VGH) between 2008 and 2018. All published English cases based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement were also included in the current review.

RESULTS

A total of 114 women from PRISMA and 3 women from Taipei VGH were identified. The uterus was the most commonly involved site (82/114, 71.9%), followed by the cervix (12/114, 10.5%). Immunohistochemical staining showed that nearly all gynecological PEComas were positive for human melanoma black 45 (113/114, 99.1%). More than half of the gynecological PEComas were immunoreactive for desmin (50/85, 58.8%). Multi-modality treatment, including surgery and mammalian target of rapamycin (mTOR) inhibitors as targeted therapy, provided long-term disease-free survival (cure rate ranging from 50% to 100%, based on the different anatomic sites of the female genital tract).

CONCLUSION

Multi-modality treatment, including cytoreductive surgery and mTOR inhibitors with/without chemotherapy and/or radiation, should be considered for the management of women with PEComas in the genital tract.

Pigmented perivascular epithelioid cell tumor (PEComa) arising from kidney: A case report

INTRODUCTION

Perivascular epithelioid cell tumor (PEComa) is a mesenchymal neoplasm composed of perivascular epithelioid cells with clear to eosinophilic cytoplasm. Pigmented PEComa arising from kidney is extraordinarily rare and sometimes can exhibit aggressive biological behavior.

CASE REPORT

We present here a rare case of pigmented renal PEComa in a 46-year-old female. The patient had complained of lumbago complicated with nausea and vomiting for 2 weeks and therefore was referred to our department. An enhanced computed scan revealed a 4 × 3 × 3 cm round-like mass in the lower pole of right kidney with inhomogeneous enhancement. The tumor cells immunestained was positive for HMB-45, focally positive for c-Kit (CD117), and negative for vimentin, S-100, AE1/AE3, CK-7, CK-18, CD-10, RCC antigen, CgA, DOG-1, EMA, smooth muscle actin, and synaptophysin. We successfully performed 3-dimensional laparoscopic resection of the neoplasm, which was then diagnosed as pigmented PEComa by postoperative pathology. No further growing lesion or metastasis was observed during a 1-year follow-up.

CONCLUSION

This case report shows that pigmented renal PEComa is often presented as a renal mass with nonspecific symptoms and imaging features. The gold diagnosis of renal pigmented PEComa is mainly based on the combination of histopathology and immunohistochemistry. Complete resection by 3-dimensional laparoscopic nephron-sparing surgery can be an effective therapeutic management.

Perivascular epithelioid cell tumors of the uterine cervix

The World Health Organization (WHO) defines PEComas as mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular cells. Uterus is the most common site of a subgroup of PEComas not otherwise specified(NOS). PEComas of the uterine cervix are extremely rare, and only thirteen cases have been described in the English literature to date. In this review, we summarize the available data concerning diagnostics, immunohistochemical analysis, genetics and treatment of cervical PEComas. Radical hysterectomy with bilateral salpingooophorectomy is the best surgical approach available. Adjuvant therapy in its present form is not efficient. Therefore, further studies are needed to evaluate the newest treatment strategies.