Femoral PEComa Treated With Combined Surgery and Radiotherapy: A Case Report

CD1a immunopositivity in perivascular epithelioid cell neoplasms: true expression or technical artifact? A streptavidin-biotin and polymer-based detection system immunohistochemical study of perivascular epithelioid cell neoplasms and their morphologic mimics

BackgroundPerivascular epithelioid cell tumors are defined by the World Health Organization as “a collection of rare mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells.” Whereas localized perivascular epithelioid cell tumor is typically benign and treated successfully with surgical resection, prognosis for patients with advanced or metastatic perivascular epithelioid cell tumor is unfavorable, and there is no standard curative treatment.Case presentationWe report a Caucasian case of metastatic perivascular epithelioid cell tumor previously treated with chemotherapy and surgery with elevated surface expression of programmed cell death ligand 1. Based on this result, treatment via immune checkpoint inhibition with the monoclonal antibody pembrolizumab was pursued. After 21 cycles, the patient sustained a complete response. Therapy was stopped after the 40th cycle, and she was moved to surveillance. She remained disease free 19 months off treatment.ConclusionsThis case report of a patient with perivascular epithelioid cell tumor treated successfully with programmed cell death protein-1 targeted therapy suggests that programmed cell death ligand-1 levels should be measured in patients with perivascular epithelioid cell tumor and immunotherapy considered for recurrent or metastatic patients. Future phase II/III studies in this disease should focus on sequencing of surgery and immunotherapy with a design of curative intent.

A perivascular epithelioid cell (PEC) tumor is a rare mesenchymal tumor characterized by abundant cytoplasmic Periodic acid-Schiff positive glycogen (also called sugar tumor or clear cell tumor of the lung for this characteristic) and is mostly benign. We report a case of a 63-year-old man who presented with an enlarging mass on chest radiograph. After a thorough workup, diagnosis of malignant pulmonary PEC tumor with lung to lung metastases was established. Herein, the difficulties of diagnosis and management we confronted are described.

Rationale:Perivascular epithelioid cell tumor (PEComa) is a mesenchymal tumor that arises from perivascular epithelioid cells and can differentiate into melanocytes and smooth muscle cells. Malignant renal perivascular epithelioid cell tumor is extremely rare. Due to the lack of specific clinical manifestations and imaging features, diagnosing PEComa depends on postoperative pathology and immunohistochemistry. Surgery is the primary treatment for malignant PEComa because the efficacy of radiotherapy and chemotherapy is uncertain. There is still a lack of unified diagnostic criteria and treatment guidelines for renal malignant PEComa, especially with vascular invasion. Hence, the treatment experience depends on a small number of cases reported worldwide.Patient concerns:A 68-year-old woman was admitted to our hospital due to intermittent hematuria for over 8 months. The color Doppler ultrasound and computed tomography scan revealed a mass in the lower middle part of the left kidney.Diagnosis:Rare renal malignant perivascular epithelioid cell tumor with renal vein cancerous thrombosis.Interventions:A laparoscopic radical left nephroureterectomy in the oblique supine lithotomy position was performed.Outcomes:The operation process went smoothly, and no pulmonary embolism occurred after the operation. The final pathological diagnosis was a renal malignant perivascular epithelioid cell tumor. After a 12-month follow-up, no recurrence or metastasis was found.Lessons:Renal malignant PEComa is an extremely rare mesenchymal tumor diagnosed mainly based on pathology. Surgery is currently the effective treatment for malignant PEComa. For the surgical treatment of malignant renal PEComa with vascular invasion, laparoscopic radical nephroureterectomy in the oblique supine lithotomy integrative position has many benefits, as exemplified by our current case.

Malignant uterine/broad-ligament perivascular epithelioid cell tumor (PEComa) coexisting with leiomyoma in a postmenopausal woman: A case report

IntroductionPerivascular epithelioid cell tumors are a family of rare mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells. They can originate in any visceral organ or soft tissue and include a range of lesions such as angiomyolipoma, clear cell 'sugar' tumor of the lung, lymphangioleiomyomatosis and clear cell myomelanocytic tumors of the falciparum ligament/ligament teres. Due to their rarity and varied sites and presentation, management of these tumors remains highly challenging.Case PresentationA 46-year-old para 2 Caucasian woman initially presented to the general surgeons at our hospital in North West London with abdominal pain. Laparoscopy revealed a right broad ligament hematoma, which was thought to be iatrogenic in origin, from insertion of the Veress needle at the time of surgery, and was managed conservatively. Upon her re-presentation two months later with severe pain, ultrasound scanning revealed the hematoma had increased in size and she underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy. Histology results from necrotic tissue from the hematoma led to a diagnosis of perivascular epithelioid cell tumor. She was then referred to a tertiary oncology center, where she underwent several further operations in an attempt to debulk the tumor for symptomatic relief of her pain, with limited success. She is now taking the immunosuppressive drug sirolimus, which has produced a modest reduction in tumor size. She is now 47 months on from initial presentation.ConclusionsA literature search has revealed only six other case reports of broad ligament perivascular epithelioid cell tumors, with varied presentations and management. The longest duration of follow-up was 21 months. Only five other cases of perivascular epithelioid cell tumor managed with sirolimus have been reported. We therefore feel that this report highlights some of the difficulties in diagnosing perivascular epithelioid cell tumors, and sheds light on management strategies for a very rare gynecological tumor in addition to sharing our experience in the use of sirolimus in its treatment.

We report a case of perivascular epithelioid cell tumor arising in the rectum of a 55-year-old woman. The tumor was treated by transanal endoscopic microsurgery. After 1 year follow-up, the patient is alive with no radiologic or endoscopic evidence of recurrence. Perivascular epithelioid cell tumor is a rare mesenchymal tumor characterized by co-expression of melanocytic and smooth muscle markers. This rare tumor can arise in various organs, including the falciform ligament, uterus, uterine cervix, liver, kidney, lung, breast, cardiac septum, pancreas, prostate, thigh, and gastrointestinal tract. Perivascular epithelioid cell tumor of the gastrointestinal tract is very rare, with only 23 previously reported cases. We review the literature on perivascular epithelioid cell tumors arising in the gastrointestinal tract.

Objective: To analyze the pathogenesis, clinical manifestations, diagnosis, treatment and prognosis of pulmonary malignant perivascular epithelioid cell tumor (PEComa) with adenocarcinoma. Methods: In August 2020, the Department of Pathology, Dongguan People's Hospital of Southern Medical University, diagnosed a case of pulmonary malignant PEComa mixed with adenocarcinoma. The clinical data, pathological diagnosis, treatment plan and prognosis of the patient were analyzed, and the literature was reviewed. Firstly, "malignant perivascular epithelioid cell tumor"+" Pulmonary "+"adenocarcinoma" was used to search CNKI and Wanfang Medical Database, but no relevant reports were found. Then, we changed the search term as "pulmonary malignant perivascular epithelioid cell tumor", and search for PubMed, Embase, Web of Science and Cochrane by combining the subject terms with "pulmonary malignant perivascular epithelioid cell tumor" and "PEComa" as subtopics. The language was Chinese or English and the search deadline was November 2020. Results: The patient, a 46-year-old male, was admitted to the hospital on August 20, 2020, due to "repeated cough and chest pain for more than 10 days, accompanied by rapid weight loss". Serology detected increased expression of lung non-small cell lung cancer related antigens. PET-CT showed a large mass of soft tissue density in the left thoracic cavity with an SUV value of 22.8. The postoperative pathological diagnosis was malignant PEComa mixed with adenocarcinoma and the lymph nodes were metastasized. Due to the detection of EGFR sensitive mutation, postoperative chemotherapy and targeted therapy were administered, and the current state was stable. A total of 12 cases of pulmonary malignant PEComa were retrieved in the literature, which were common in middle-aged and elderly people. They usually presented with cough or chest tightness. Chest CT mostly showed round masses with clear boundaries, and 8 cases had metastasis to mediastinal lymph nodes and other organs. Conclusions: Pulmonary malignant PEComa is rare. It is the first report of the same mass with lung primary adenocarcinoma. The tumor progresses rapidly. Complete surgical resection of the lesion and lymph node dissection are more appropriate treatment strategies, supplemented by postoperative chemotherapy and targeted therapy. For cases diagnosed as pulmonary PEComa, long term follow-up should be performed, even if the pathological diagnosis is benign.

Introduction: Perivascular epithelioid cell tumor (PEComa) is a rare neoplastic mesenchymal tumor, more frequently found in the uterus, although it can occur in different organs. Hepatic PEComa is extremely rare, with only a few cases described in the literature. Case Presentation: We present a case report of a 33-year-old female patient with a history of macroprolactinoma. She was initially referred to our Department due to a 9-mm hepatic nodule incidentally diagnosed in an abdominal ultrasound in 2018. She was asymptomatic. Follow-up ultrasound showed a growth from 9 mm to 16 mm in 2019 and 30 mm in a liver magnetic resonance imaging (MRI) scan in 2022. The case was discussed in a multidisciplinary team meeting, and since malignant transformation or hepatocellular carcinoma could not be ruled out, the decision was to undergo hepatic resection. An open hepatic subsegmentectomy of segment 5 was performed, with uneventful postoperative period. The definitive diagnosis was hepatic PEComa. Conclusion: Hepatic PEComas are rare liver tumors, and their preoperative diagnosis is challenging due to the lack of specific radiological features. In most cases, the diagnosis is only confirmed through histopathological and immunohistochemical studies. Resection of the lesion appears to be the curative treatment; however, due to the rarity of the condition, there are no studies comparing surgical treatment with other options. In our case, the hypervascular lesion was initially misdiagnosed as an adenoma. PEComas should be considered as a differential diagnosis in liver nodules with well-defined margins and increased uptake in the arterial phase in computed tomography or MRI scan. Surgical resection was curative, and no recurrence was detected during the patient’s follow-up.

Perivascular epithelioid cell tumors are rare mesenchymal neoplasms composed of histologically and immunohistochemically distinctive perivascular epithelioid cells. The perivascular epithelioid cell tumor family includes angiomyolipoma, clear cell sugar tumor of the lung, lymphangioleiomyomatosis, clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres, and rare clear cell tumors of other anatomic sites. Perivascular epithelioid cell tumors have been reported previously in various sites, but to our knowledge not in the gallbladder. We report here, for the first time, a malignant perivascular epithelioid cell tumor arising in the gallbladder.

An unusual case of uterine PEComa presenting with disseminated intravascular coagulation

We describe a young female patient suffering from a PEComa (perivascular epithelioid cell tumor) of the cecum, incidentally found at an examination made by her family physician. The perivascular epithelioid cell tumor is a very rare tumor, until today reported in a few cases in falciform ligament, uterus, jejunum, terminal ileum, rectum, liver, kidney, lung, pancreas, prostate, and soft tissue of the thigh. This tumor is part of a new group of tumors, comprised of angiomyolipoma, lymphangiomyolipoma, and clear-cell myomelanocytic "sugar" tumor. Defined by coexpression of melanocytic (HMB-45) and muscle markers (smooth muscle actin and desmin) the perivascular epithelioid cell tumor does not have predictable histopathologic behavior. Some cases of metastasis are described, comorbidities such as tuberous sclerosis of the brain "Bourneville" and lymphangioleiomyomatosis have to be excluded. The therapy consists of the radical resection. An adjuvant therapy is not known. Recommended is a close and long-term follow-up clinically and by CT scan.

Perivascular epithelioid cell tumour is a rare mesenchymal tumour with distinct immunohistochemical profile. While it is known to occur in various anatomical sites, the central nervous system had always been a protected site for primary or secondary perivascular epithelioid cell tumours. We describe a 61-year-old lady who presented with symptoms of raised intracranial pressure, 3 months after the resection of duodenal and thoracic tumours which were histologically consistent with perivascular epithelioid cell tumour. She was investigated and then subsequently subjected to resection of two metastatic intracranial lesions. The radiological, intraoperative as well as histopathological findings of the metastatic lesions are discussed. Metastatic perivascular epithelioid cell tumour of the brain is extremely rare. However, patients who are stratified as high risk for recurrence or metastases should undergo an early magnetic resonance imaging/computed tomography of the brain in addition to a whole-body positron emission tomography scan, to allow for early detection and management of these tumours.

Perivascular epithelioid cell tumor (PEComa) is a rare entity with distinctive morphology and of expressing myomelanocytic markers. Gastrointestinal tract (GI) is one of the most common anatomic sites of origin and counts for 20% to 25% of all reported cases of perivascular epithelioid cell tumors not otherwise specified (PEComas-NOS). However, the biologic behavior of perivascular epithelioid cell tumors of gastrointestinal tract (GI PEComas-NOS) is still unclear. The aim of conducting this systematic review is to sum up what is known so far of the epidemiology, natural history, management and prognosis of GI PEComas-NOS.A systematic research was performed on PubMed and EMBASE using the following terms: ("perivascular epithelioid cell tumor" or "PEComa") and ("gastrointestinal tract" or "GI" or "oral " or "mouth" or "esophagus" or "gullet" or "gastric" or "stomach" or "duodenum" or "jejunum" or "ileum" or "cecum" or "colon" or "colorectal" or "sigmoid" or "rectum" or "anus" or "mesentery") up to December 1, 2015. Retrieved GI PEComas-NOS publications, which included these terms, contains case reports, case series to case characteristic researches.A total of 168 articles were reviewed, 41 GI PEComa-NOS English studies among which were retrieved for analysis. We reviewed epidemiology, natural history, management and prognosis of GI PEComa-NOS. Generally GI PEComa-NOS is believed to have women predomination. The most frequently involved location is colon with non-specific clinical signs. Pathologically, GI PEComas-NOS shows epithelioid predominance (70%), meanwhile coexpresses melanocytic and muscle markers characteristically, while immunohistochemistry is a useful tool for identify, which indicates that HMB-45 is regarded as the most sensitive reagent. Complete resection served as mainstay of treatment, while chemotherapy should be unanimously considered to apply in malignant cases. Eventually, it is necessary for closed and long-term follow-up with endoscope and imaging for ruling out local recurrence or distant metastasis of this tumor.GI PEComas-NOS lives with unclear behavior. There are still many unverified clinicopathological issues of GI PEComas-NOS that needs to be clarified. Further studies and analyses concerning this rare entity should be brought out. Thus, the randomized clinical researches (RCTs) are required to be conducted.

Perivascular epithelioid cell tumors (PEComas) are rare neoplasms that share phenotypic features with angiomyolipomas, clear cell sugar tumors, and lymphangioleiomyomatosis. They presumably represent the neoplastic counterpart of a yet-unidentified perivascular epithelioid cell that expresses smooth muscle and melanocytic immunomarkers. The uterus is the second most common site of origin for perivascular epithelioid cell tumors, after the retroperitoneum. Although most uterine perivascular epithelioid cell tumors are clinically benign and can be cured by a complete surgical excision, there is a subset characterized by both local and distant dissemination. Unfortunately, no single histopathologic or immunohistochemical parameter can accurately predict the clinical behavior of these tumors, which is why the 2012 World Health Organization classification of tumors of the female reproductive organs suggests the use of several criteria to predict the risk of aggressive clinical behavior. Here we review those perivascular epithelioid cell tumors of the uterine corpus with aggressive clinical behavior reported in the literature, and we discuss their most relevant clinical and histopathologic features.