Malignant Perivascular Epithelioid Cell Tumor (PEComa) of the Uterus: Serial Imaging With F-18 FDG PET/CT for Surveillance of Recurrence and Evaluation of Response to Therapy

Gynecologic perivascular epithelioid cell tumors (PEComas): a review of recent evidence

Gynecologic perivascular epithelioid cell (PEC) tumors, or 'PEComas,' represent a rare and intriguing subset of tumors within the female reproductive tract. This systematic literature review aims to provide an updated understanding of gynecologic PEComas based on available literature and data. Although PEComa is rare, there are varied tumor-site presentations across gynecologic organs, with uterine PEComas being the most prevalent. There is scarce high-quality literature regarding gynecologic PEComa, and studies on malignant PEComa underscore the challenges in diagnosis. Among the diverse mutations, mTOR alterations are the most prominent. Survival analysis reveals a high rate of local recurrence and metastatic disease, which commonly affects the lungs. Treatment strategies are limited, however mTOR inhibitors have pivotal role when indicated and chemotherapy may also be used. with some cases demonstrating promising responses. The paucity of data underscores the need for multicentric studies, an international registry for PEComas, and standardized reporting in case series to enhance clinical and pathological data.

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.

Systematic analysis of perivascular epithelioid cell neoplasms in the female reproductive tract: a comprehensive review

Perivascular epithelioid cell neoplasms (PEComas) are rare mesenchymal lesions, with gynecological PEComas accounting for just over a quarter of cases. Limited reports exist on gynecological PEComa, primarily treated with surgery; adjuvant therapy is considered in high-risk cases. This systematic review aims to summarize the origin and clinical, pathological and molecular characteristics of uterine PEComa, focusing on treatment options for gynecological PEComa. A comprehensive PubMed review of gynecological PEComa reports was conducted. A detailed examination of the literature ensured a thorough understanding. Gynecological PEComa diagnosis relies on histology and immunology. Despite therapy controversies, surgery remains the mainstay. Adjuvant therapy efficacy in high-risk cases is uncertain. mTOR inhibitors are the first line; alternative treatments, including angiogenesis and aromatase inhibitors, should be considered.

Pancreatic PEComa, a not so uncommon neoplasm? Systematic review and therapeutic update

Pancreatic PEComas are extremely rare neoplasms with malignant potential, which mostly affect middle-aged women and are characterized by presenting melanocytic and myogenic markers in immunohistochemical analysis. There are no symptoms or pathognomonic imaging tests, so the diagnosis is established with the analysis of the surgical specimen or the FNA obtained with preoperative endoscopic ultrasound. The mean treatment consists on radical excision, adapting the intervention to the location of the tumor. To date, 34 cases have been described; however, more than 80% of them have been reported in the last decade, which suggests that it is a more frequent pathology than expected. A new case of pancreatic PEComa is reported and a systematic review of the literature is carried out according to the PRISMA guidelines with the aim of divulge this pathology, deepening its knowledge and updating its management.

Pancreatic Perivascular Epithelioid Cell Tumor Revealed by 68 Ga-DOTATATE PET/CT

ABSTRACT

We report 68 Ga-DOTATATE PET/CT findings of pancreatic perivascular epithelioid cell tumor in a 55-year-old woman. 68 Ga-DOTATATE PET/CT showed increased radioactivity in the region of pancreatic body, which suggested malignant tumor. However, postoperative pathological findings demonstrated the presence of perivascular epithelioid cell tumor. This case emphasizes the need to increase awareness of this tumor in the differential diagnosis of pancreatic nodules with moderate DOTATATE activity.

Rare perivascular epithelial cell tumor of the colon 18F-FDG PET/CT imaging: A case report

RATIONALE

Neoplasms with perivascular epithelioid cell differentiation (PEComas) are mesenchymal tumors that rarely occur in the colon. Here, we report the occurrence of a malignant PEcoma in the colon using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT).

PATIENT CONCERNS

A 55-year-old woman was admitted to the hospital with abdominal pain for 10 days and a self-induced abdominal mass for 3 days. 18F-FDG PET/CT imaging showed a large hypermetabolic nodule and mass in the right mid-upper abdomen with heterogeneous density and a further increase in metabolism on the delayed scan.

DIAGNOSES

PEComa of the colon.

INTERVENTIONS

Tumor resection was performed.

OUTCOMES

The patient is well after 2 months of treatment, pending further follow-up.

LESSONS

Malignant perivascular epithelioid cell tumors originating in the colon are extremely rare, and our report suggests that PEComa should be considered as a differential diagnosis for 18F-FDG gastrointestinal malignancies. Additionally, 18F-FDG PET/CT may play a key role in the staging and extent of lesions in intestinal malignancies.

18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Response Assessment of Perivascular Epithelioid Cell Tumor of the Pelvic Cavity to Irinotecan and Temozolomide

Perivascular epithelioid cell tumors (PEComas) are a rare variety of mesenchymal tumors composed of distinctive cells that show a focal association with blood vessel walls and usually express melanocytic and smooth muscle markers. We present a case of 38-year-old male, diagnosed with PEComa of the pelvic cavity who underwent serial ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography scans for the assessment of response to the chemotherapeutic combination of irinotecan and temozolomide.

18F-FDG PET/CT for Monitoring of Disease Progression in Metastatic Perivascular Epithelioid Cell Tumor

ABSTRACT

A 38-year-old woman presented for 18F-FDG PET/CT after multiple intra-abdominal surgical resections of a rare recurrent perivascular epithelioid cell tumor of the gastrointestinal tract. A solitary pelvic metastasis was detected, but surprisingly exhibited neither increased glucose consumption nor contrast enhancement on CT. Follow-up 18F-FDG PET/CT staging in the further disease course revealed multiple abdominal metastases, now, however, with markedly increased 18F-FDG uptake and intraoperatively correlating widespread peritoneal sarcomatosis. This case gives preliminary insight into monitoring of disease progression in metastatic perivascular epithelioid cell tumor, although the underlying pathophysiological bases for varying 18F-FDG uptake in PET/CT are not yet fully understood.

Primary perivascular epithelioid cell tumor (PEComa) in bone: A review of the literature and a case arising in the humerus with multiple metastases

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First case PEComa primary arising in humerus was described.

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Histology is the basic to determine malignancy of PEComa.

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TFE3 gene investigation is the key of therapy selection.

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mTOR inhibitor is believed to be effective for patients without TFE3 rearrangement.

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More study is needed to understand the role of molecular test and imaging in PEComa.

Introduction

Perivascular epithelioid cell tumors (PEComas) are a family of mesenchymal tumors that rarely arise as a primary bone tumor.

Material and methods

We report a case of primary malignant bone PEComa. A literature review via PubMed, Embase and Web of Science databases with the keyword “PEComa” and “bone” was performed.

Results

We reported a 33-year-old female with primary malignant bone PEComa in right distal humerus. The patient received an inhibitor of the mammalian target of rapamycin (mTOR) protein based on negative molecular investigation result of transcription factor E3 (TFE3) rearrangement, and additional therapies including palliative radiotherapy, anti-angiogenics and immunotherapy when the disease progression was detected. The patient was alive with the disease twenty-three months postoperatively. A total of nineteen related literature cases were retrieved and reviewed. Taking current case into account, ten males and ten females with median age of 24 years (range, 3–93 years) were identified, who were most frequently affected in tibia. The median follow-up duration of 24 months (range, 3–96 months). One patient died due to this disease, and six patients showed metastases. Three patients experienced recurrence, and two of them experienced twice and three times, respectively.

Conclusion

To our knowledge, this is the first case of primary malignant bone PEComa arising in humerus. Clinicopathological and radiological correlation is mandatory to the correct diagnosis and to determine its malignancy. More studies are required to understand the role of molecular test and imaging in selecting suitable treatment and mechanisms of treatment resistance.

Malignant perivascular epithelioid cell tumor of the ileum on 18F-fluorodeoxyglucose positron emission tomography/ computed tomography with pathological correlation

A 75-year-old woman presented with a 1-month history of abdominal pain. Contrast-enhanced computed tomography (CT) demonstrated a large solid mass in the left lower abdominal quadrant, suspicious for malignancy. Staging with ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/CT imaging demonstrated intense FDG uptake in the mass with no evidence of metastatic disease. Complete surgical resection was performed, and histopathological analysis confirmed a malignant perivascular epithelioid cell tumor of the ileum.

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.

Malignant Perivascular Epithelioid Cell Tumor of Lung on FDG PET/CT

Chest CT images were acquired in a 67-year-old man to evaluate a left lung mass revealed by chest radiography. The image findings suggested possible pulmonary malignancy. FDG PET/CT was performed for staging, which showed the abnormally increased activity in the lung mass with hypermetabolic lymph node. Pathology from the biopsy confirmed malignant perivascular epithelioid cell tumor.

Malignant perivascular epithelioid cell tumor of the lung synchronous with a primary adenocarcinoma: one case report and review of the literature

BACKGROUND

Perivascular Epithelioid Cell Tumors (PEComa) is an extraordinarily rare mesenchymal neoplasm especially the malignant type originating from the lung. To date, only 8 cases of malignant or malignant potential pulmonary PEComa had been documented. Firm diagnostic criteria for malignant pulmonary PEComa need urgently to be established.

CASE PRESENTATION

We report a challenging case of malignant pulmonary PEComa combined with a primary adenocarcinoma in a 54-year-old man. The PEComa-like tumor showed strong Melan-A and weak transcription factor E3 (TFE3) protein expression but no TFE3 gene rearrangement. The carcinoma-like nodule was recognized as a poorly differentiated primary lung adenocarcinoma.

DISCUSSION AND CONCLUSIONS

Our case report was the first case of malignant pulmonary PEComa synchronous with a primary adenocarcinoma and studied the dilemma of diagnosing benign versus malignant criteria for this uncommon tumor.

Unresectable hepatic PEComa: a rare malignancy treated with stereotactic body radiation therapy (SBRT) followed by complete resection

BACKGROUND

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors occurring in various anatomic regions. Although diagnostic criteria and treatment management are not established, current treatment options consist of surgery and chemotherapy including mTOR inhibitors. Stereotactic body radiation therapy (SBRT) is a non-invasive ablative treatment which has shown excellent control rates for more common types of unresectable liver tumors and metastases. In this report we present a rare case of PEComa of the liver that was treated by stereotactic radiotherapy followed by resection. Staging and evaluation of treatment response was done by FDG-PET/CT. This case highlights the potential of SBRT as a neoadjuvant treatment even for rare liver malignancies. It is the first case of liver PEComa treated by SBRT and resection.

CASE PRESENTATION

A 52-year-old woman presented at an external hospital with abdominal pressure and pain in the right upper abdominal quadrant. A CT scan showed a 700 cm3 liver lesion in segment IV. In repeated biopsy in July 2015 histopathological workup showed a pleomorphic epitheloid tumor with small to medium sized cells expressing vimentin and melan-A while being negative for cytokeratin establishing the diagnosis of PEComa of the liver. To achieve high, ablative doses a stereotactic body radiotherapy (SBRT) technique was chosen consisting of 60Gy (biologically effective dose 105Gy) in 8 fractions of 7.5Gy. Radiotherapy planning was based on MRI resulting in a planning target volume (PTV) of 1944 cm3. Treatment toxicity was limited to a slight elevation of transaminases (grade 1 and 3). A complete resection was performed 21 weeks after radiotherapy confirmed by negative surgical margins. At last follow-up 21 months after therapy, MRI showed neither local nor distant tumor recurrence. The patient was in stable condition (ECOG 1) and without late radiation toxicity.

CONCLUSIONS

This is the first documented case of liver PEComa treated by SBRT and resection. A favorable post-treatment course demonstrates that SBRT is a potential neoadjuvant treatment that is capable of reducing an inoperable rare liver tumor to a resectable lesion.

Uterine Metastasis From Gastric Adenocarcinoma Masquerading as Physiologic Endometrial Uptake in FDG PET/CT

A 44-year-old woman with newly diagnosed gastric adenocarcinoma by gastroscopy underwent F-FDG PET/CT to evaluate possible metastasis. The images demonstrated intense activity in the region of uterine corpus, as well as greater gastric curvature. Physiologic uptake of endometrium was initially suspected, given the rarity with which extragenital cancers metastasize to the uterus. Ultimately, the endometrium proved to be mucinous adenocarcinoma of gastric origin based on its shared histological features and compatible immunostaining profile.

Update on the imaging of malignant perivascular epithelioid cell tumors (PEComas)

Malignant perivascular epithelioid cell tumors (PEComas) are a histologic group of mesenchymal neoplasms that share a distinctive histological phenotype, the perivascular epithelioid cell. These tumors are known for their perivascular distribution. Malignant PEComas have a female predominance and are associated with aggressive disease and poor prognosis, making timely diagnosis critical to management. Imaging features of malignant PEComas are nonspecific and mimic other benign and malignant neoplasms. Surgery is the mainstay in the management of malignant PEComas. Promising novel molecular targeted therapies like m-TOR inhibitors have been shown to be effective in the metastatic setting. The aim of this review is to familiarize radiologists with the imaging appearances of and potential therapies for primary and metastatic malignant PEComa.

The role of (18)F-FDG PET/CT imaging in patient with malignant PEComa treated with mTOR inhibitor

Malignant perivascular epithelioid cell tumor (malignant PEComa) is a rare disease for which the diagnostic criteria and treatment options have not been established. Since PEComa is associated with upregulation of mammalian target of rapamycin (mTOR) pathway which controls Glut-1 (glucose transporter) function, increased ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake may indicate the over activation of mTOR pathway and may guide selectively inhibiting mTOR pathway treatment. We report a malignant PEComa patient who presented for ¹⁸F-FDG positron emission tomography/computed tomography (PET/CT) restaging. The tumor had shown significant avidity on PET/CT as well as an evident response to sirolimus (rapamycin, Rapamune™) that supports the utility of mTOR inhibitors as an effective treatment for malignant PEComa. Therefore, ¹⁸F-FDG PET/CT is helpful in restaging and guiding treatment for malignant PEComa with mTOR inhibitors.

Perivascular epithelioid cell neoplasm (PEComa) of the uterus: A systematic review

BACKGROUND

Perivascular epithelioid cell neoplasm (PEComa) is a rare mesenchymal tumor. Gynecological PEComas account for just over one-fourth of the overall PEComa cases reported in the literature. Surgery is the most recommended primary treatment while adjuvant therapy is generally reserved for high-risk cases. However, the best management of this neoplasia has not been well established, primarily because of the paucity of cases described to date.

OBJECTIVES

The aim of this systematic review is to summarize what is known thus far regarding the etiopathogenesis, clinical and pathologic features of PEComas, focusing also on the most valid treatment options for uterine cases.

DATA SOURCES

Pubmed articles on PEComas published in various journals over the past 70 years were analyzed.

CONCLUSIONS AND KEY FINDINGS

Although the optimal treatment of gynecological PEComas is controversial, surgical resection remains the cornerstone. The use of adjuvant treatment is warranted in high risk patients to increase disease control. A multidisciplinary approach should be key in treatment decision-making regarding gynecological PEComas.

Imaging features of primary and metastatic malignant perivascular epithelioid cell tumors

OBJECTIVE

The objective of our study was to describe the imaging features of primary and metastatic malignant perivascular epithelioid cell tumors (PEComas).

MATERIALS AND METHODS

In this retrospective study, 36 patients (26 women, 10 men; mean age, 53.1 years; age range, 35-77 years) with a histopathologically confirmed diagnosis of malignant PEComa who were seen at our institute between January 2007 and December 2012 were included. Pretreatment imaging of the primary tumor in 17 patients (CT, n = 13; MRI, n = 9; ultrasound, n = 5) and follow-up imaging in all 36 patients (CT, n = 36; MRI, n = 7) were reviewed by three radiologists in consensus.

RESULTS

The most common site of presentation of malignant PEComas was the retroperitoneum (38.9%) followed by the female genital tract (27.8%). Kidneys (8/36) and uterus (8/36) were the organs most frequently involved. The mean largest dimension was 11.01 cm (range, 4.5-25 cm). Primary tumors were well-circumscribed masses (16/17), were heteroechoic on ultrasound (5/5), were hypodense (2/6) to isodense (4/6) enhanced significantly (11/12) and compared with the paraspinal muscles on CT, were hypointense to isointense compared with skeletal muscle on T1-weighted imaging (8/9), were heterogeneously hyperintense compared with skeletal muscle on T2-weighted imaging (9/9), and showed significant post-gadolinium enhancement (7/7) on MRI. Of the 17 primary tumors, necrosis was seen in seven tumors, hemorrhage in three tumors, and calcification in three tumors. Twenty-six of 36 (72%) patients developed metastases, most commonly to the lung (21.6%), liver (17.6%), and peritoneum (10.8%).

CONCLUSION

Malignant PEComas in our study were large tumors that most often arise in the kidneys and uterus and metastasize to lungs, liver, or peritoneum. In our experience malignant PEComas should be considered in the differential diagnosis of large well-circumscribed renal and uterine tumors.