Pneumothorax caused by cystic and nodular lung metastases from a malignant uterine perivascular epithelioid cell tumor (PEComa)

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.

A successful case of complete surgical resection via left upper and right lower lobectomy for bilateral lung metastases of a perivascular epithelioid cell tumor in the colon: a case report

Background

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal neoplasms with malignant potential. No effective treatment other than surgical resection has been established for lung metastases of PEComas. We describe a patient who underwent complete surgical resection via bilateral lobectomy involving a two-step procedure for lung metastases 8 years after undergoing radical surgery for a colonic PEComa.

Case presentation

A 53-year-old woman underwent partial colectomy for a PEComa in the transverse colon 8 years ago. She presented with an abnormal chest shadow during a health examination. Chest computed tomography (CT) revealed a solid nodule 2 cm in diameter located centrally in the right lower lobe and a solid nodule 3 cm in diameter located centrally in the left upper lobe. Positron emission tomography revealed 18F-fluorodeoxyglucose uptake in these nodules. These nodules were suspected to be metastatic tumors of the colonic PEComa and were considered for complete surgical resection. Segmentectomy could not be performed because of the anatomical location of the tumors straddling the segments; therefore, bilateral lobectomy was required for complete surgical resection. Therefore, we performed two-step lobectomy safely with the expectation of pulmonary function recovery. Microscopically, the tumors were diagnosed as lung metastases of the PEComa. One year after the last surgery, no recurrence was detected, and the patient’s pulmonary function improved.

Conclusions

This case indicates that even if multiple lung metastases of a PEComa require bilateral lobectomy, complete resection with a two-step surgery may be considered.

Natural History and Treatment Strategies of Advanced PEComas: A Systematic Review

Simple Summary

In this article, we review the clinical features of advanced PEComas and show the diversity of reported data among authors, emphasizing the heterogeneity of molecular characterization and treatment strategy. Based on clinical data collected from 124 case reports, metastatic disease at diagnosis and a grouped version of the Bleeker’s risk category were the only factors significantly associated with death. Due to a significant number of missing data or short follow-ups, results regarding prognostic factors should, however, be interpreted with caution.

Abstract

PEComas is a family of rare mesenchymal tumors. This systematic review aims to better understand the natural history of advanced PEComas. After a search on the PubMed database and main oncology meeting libraries according to the PRISMA guidelines, 88 articles reported in the English literature were included. Data on clinical and histological features, treatments and outcomes were collected. To identify risk factors, univariate and multivariate analyses were performed. Seven cohorts of patients and 124 individual patients were identified. Focusing on case reports, most patients were metastatic, and the median overall survival (OS) of the entire cohort was 60 months (95%CI 33; NA). Risk factors significantly associated with OS in the multivariate analysis were the presence of metastasis at diagnosis (HR: 2.59, 95%CI 1.06; 6.33, p = 0.036) and the grouped-Bleeker’s risk category (HR: 4.66; 95%CI 1.07; 20.19; p = 0.039). In the metastatic population, only the presence of lymph node metastasis was associated with OS (HR: 3.11; 95%CI 1.13; 8.60, p < 0.05). Due to a lack of events, it was not possible to conclude on other factors. This review of the literature highlights the heterogeneity of literature data and shows the great diversity of clinical management strategies.

Perivascular epithelioid cell tumors (PEComa) of the female genital tract: A challenging question for gynaecologic oncologist and pathologist

Perivascular epithelioid cell tumors (PEComa)s are mesenchymal neoplasms composed of perivascular epithelioid cells, which express both melanocytic and myogenic markers. These neoplastic cells are thought to arise from undifferentiated cells of the neural crest, or from myoblastic cells harbouring a molecular alteration leading to expression of melanocytic markers, or from pericytic cells. The majority of cases are benign, but a small subset behaves in a malignant fashion. Unfortunately, given their rarity, reliable criteria for predicting malignancy have yet to be established. PEComas of the female genital tract account for nearly 25% of PEComas of all body sites, and the most common site of occurrence is the uterine corpus; less common sites include the cervix, adnexa, vagina/vulva or broad or round ligament exceptionally. The present review aims to elucidate the clinical, pathological and molecular features of gynecological PEComas. Moreover, prognostic and therapeutic implications are also discussed.

Histopathologic characteristics and immunotypes of perivascular epithelioid cell tumors (PEComa)

OBJECTIVES

In order to provide further evidence for the origin and differentiation of PEComa, the clinicopathologic and immunophenotype findings were analyzed in 26 cases with literature review.

METHODS

Immunohistochemistry and special staining were used.

RESULTS

Multinucleated giant cells and polymorphism were scattered visibly in 53.8% and 76.9% of the cases and spotty necrosis and hemorrhage were observed in 38% of the cases. Capsular micro-invasion was detected in 46% cases accompanied by hemorrhage and/or necrosis in the tumors with diameters larger than 5 cm. It was also found that 100% of cases diffusely expressed SMA, Melan-A, and vimentin except one negative for HMB-45. The tumor cells partly expressed CD56, CD99, desmin, and S-100 and were negative for CK-pan, TFE3, CD117, CD44, and CD34. Clinical follow-up found that 22 out of 23 patients were alive, with no recurrence or progression, ranging from 42 to 82 months. However, one patient died from leukemia.

CONCLUSIONS

In this study, the histopathologic features with the co-expressions of SMA and melanin, were the diagnostic basis of PEComas. The interspersed expressions of desmin and S-100 were helpful for the differential diagnosis of leiomyoma and neuroma. The expressions of S-100, CD56, and CD99 supported the origins of the pluripotent cells from the neural crests. Tumors larger than 5 cm in diameter with micro-hemorrhaging/necrosis and micro-capsular invasions should be considered either uncertain or of malignant potential. The spontaneous rupturing of blood vessels may be related to the amyloidosis and desmin negative expression, and broken elastic fibers.

Multifocal perivascular epithelioid cell tumor of the uterus: report of one case and literature review

BACKGROUND

The tumor with perivascular epithelioid cells (PEComa) is a rare mesenchymal tumor originating from a perivascular epithelioid cell line. The uterus is the most common location of PEComa, but multifocal lesions are rare. This study aimed to analyze the clinicopathologic and histochemical characteristics of uterine PEComa.

METHODS

1 case of uterine PEComa was detected by H&E staining and immunohistochemical SP method.

RESULTS

The 41-year-old female patient was admitted to the hospital due to gynecologic ultrasonography which showed a substantial heterogeneous mass in the pelvic cavity. According to the microscopic features and immunohistochemical markers, the tumor was diagnosed as multifocal tumors with perivascular epithelioid cells, specifically located on the serous surface of the uterus and below the right appendix. The immunophenotype of the patient was positive for Vimentin, HMB45, TFE-3 and WT-1, but negative for SMA, S-100, CD10, CK, EMA, CD117, CD31 and Melan-A.

CONCLUSION

PEComa is a rare mesenchymal tumor with benign manifestations. Pathological diagnosis should be combined with morphology and immunophenotype. The characteristic immunomarkers are HMB45, Melan-A and SMA. The understanding of clinical manifestations and pathologic features can improve the diagnosis and prevention of this type of tumor in female patients.

Hormonal therapy in uterine sarcomas

Uterine sarcomas (USs) are a group of rare but aggressive uterine malignancies, accounting for only 1% of the malignant tumors of female reproductive organs. Due to the high rate of recurrence and metastasis, the prognosis of USs is poor. Given the high mortality rate and limited clinical benefit of surgery and adjuvant chemoradiotherapy, hormonal therapy has shown good prospects in recent years. Hormonal agents include progestins, aromatase inhibitors (AIs), and gonadotropin‐releasing hormone analogue (GnRH‐a). According to the literature, hormonal therapy has been confirmed effective for recurrent, metastatic or unresectable low‐grade endometrial stromal sarcoma (LGESS) and hormone receptor positive (ER+/PR+) uterine leiomyosarcoma (uLMS) with favorable tolerance and compliance. Besides, hormonal therapy can also be used in patients with early‐staged disease who desire to preserve fertility. However, due to the rarity of USs, the rationale of hormonal therapy is generally extrapolated from data of hormone‐sensitive breast cancer, and present studies of hormonal therapy in USs were almost limited to case reports and small‐sized retrospective studies. Therefore, further systematic researches and standardized clinical trials are needed to establish the optimal hormonal therapy regimen of USs. Herein, we reviewed the existing studies related to the hormonal therapy in USs in order to provide reference for clinical management in specific settings.

Thoracoabdominal imaging of tuberous sclerosis

Imaging of tuberous sclerosis complex has rapidly evolved over the last decade in association with increased understanding of the disease process and new treatment modalities. Tuberous sclerosis complex is best known for the neurological symptoms and the associated neuroimaging findings, and children with tuberous sclerosis complex require active surveillance of associated abnormalities in the chest, abdomen and pelvis. Common findings that require regular imaging surveillance are angiomyolipomas in the kidneys and lymphangioleiomyomatosis in the chest. However multiple rarer associations have been attributed to tuberous sclerosis complex and should be considered by radiologists reviewing any imaging in these children. In this review the authors discuss the spectrum of imaging findings in people with tuberous sclerosis complex, focusing on MR imaging findings in the chest, abdomen and pelvis.