Malignant PEComa of the lumbar vertebra: a rare bone tumour

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.

Fibroma-like perivascular epithelioid cell tumor: a rare case in a long bone

Fibroma-like perivascular epithelioid cell (PEComa) tumor is an extremely rare family of mesenchymal tumors composed of cells co-expressing melanocytic and myogenic markers. To date, 13 cases of primary bone PEComa have been reported in the literature and five reported fibroma-like PEComas were found in the soft tissues of patients with tuberous sclerosis (TSC). However, no fibroma-like PEComa has been reported in bone, either sporadic or TSC-associated. Here we report the case of a 22-year-old man with known TSC, who presented for evaluation of an asymptomatic mass in his left fibula diaphysis that had been present for 5 years. He had no activity-related pain, numbness, weakness, or limitations in range of motion. Both 3-T MRI and CT demonstrated a tumor originating from the midshaft middiaphyseal fibula. Axial T1-weighted and fat-saturated T2-weighted fast spin echo images showed a well-defined lesion in the fibula with extension into the surrounding soft tissues. Whole body bone scan was negative for metastasis using technetium-99m. Renal ultrasound was unremarkable with no evidence of angiomyolipoma. Histopathology demonstrated isolated spindle cells in a dense collagenous matrix. By immunohistochemical staining, tumor cells were positive for HMB-45 and MiTF and partially positive for alpha-smooth muscle actin supporting a diagnosis of fibroma-like PEComa of the midshaft fibula. Although fibroma-like PEComa of bone is very rare, a bone tumor in the setting of TSC should raise suspicion for the diagnosis, in particular if histology demonstrates rare epithelioid cells in a densely fibrotic stroma.

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.

Tibial perivascular epithelioid cell tumour (PEComa). A case report and literature review

INTRODUCTION

Perivascular epithelioid cell (PEC) is a cell type constantly present in a group of tumours including angiomyolipoma (AML), clear-cell «sugar» tumour (CCST) of the lung and extrapulmonary sites, lymphangioleiomyomatosis (LAM), and clear-cell tumours of other anatomical sites. It has morphologic distinctive features: epithelioid appearance with a clear to granular cytoplasm, a round to oval, centrally located nucleus and an inconspicuous nucleolus. Immunohistochemically, PEC expresses myogenic and melanocytic markers. Eleven cases of primary bone PEComa presentation have been described since 2002.

OBJECTIVE

To report a case of primary bone perivascular epithelioid cell tumour.

CASE REPORT

24 year-old male presented with pain. X-ray revealed an osteolytic lesion at right proximal tibia with soft tissue extension. Evaluation of slides identified a bony perivascular epithelioid cell tumour without immunohistochemical study confirmation.

RESULTS

Patient was treated by surgical excision and adjuvant chemotherapy (epirubicin/cysplatin). After two years of follow-up the patient remains disease free.

CONCLUSIONS

This is the first-case report in Latin America. Immunohistochemical stains were negative and we believe it may be due to non-described ethnic variations.

Primary malignant perivascular epithelioid cell neoplasm (PEComa) of the bone mimicking granular cell tumor in core biopsy: A case report and literature review

The present study investigated the case of a 46-year-old female with primary malignant perivascular epithelioid cell neoplasm (PEComa) of the femur. The patient presented with a 5-month history of right distal thigh pain following trauma. Radiographs of the right distal femur revealed a mixed lytic and sclerotic lesion with subtle areas of cortical destruction and soft tissue extension, consistent with an aggressive tumor. A core biopsy revealed an epithelioid tumor with granular cell features, but a definitive diagnosis could not be made. Due to the aggressive features on radiologic evaluation, the patient underwent a resection of the distal femur and reconstruction with a distal femoral megaprosthesis and hinged knee replacement. The post-resection pathology led to a final diagnosis of primary bone PEComa, with histologic features including epithelioid, granular cell and spindled cell morphologies and biphasic immunoreactivity for melanocytic and smooth muscle markers. The large tumor size (>5 cm), rapid mitotic rate, infiltrative growth pattern, high nuclear grade and cellularity, and the presence of necrosis rendered this a malignant PEComa. The present study discussed the case, including radiographic (radiographs, magnetic resonance imaging and positron emission tomography scans) and histologic appearance and a literature review.

Hepatic falciform ligament clear cell myomelanocytic tumor: A case report and a comprehensive review of the literature on perivascular epithelioid cell tumors

Background

The objective of the study was to explore the clinical expression, radiological and pathological features, differential diagnosis, and biological behavior of a clear cell myomelanocytic tumor. In a case involving a clear cell myomelanocytic tumor located in the hepatic falciform ligament, we evaluated clinical expression, radiological characteristics, histopathology, immunohistochemistry, and biological behavior; we also reviewed the relevant literature.

Case presentation

Clear cell myomelanocytic tumor is a benign soft-tissue neoplasm that often occurs in women, and is expressed as a painless mass. The falciform ligament is its most frequent site of occurrence. The imaging characteristics of this lesion were uneven enhancement in the arterial phase, continuing to strengthen in the venous phase, and equal density in the balance phase. Histological and immunohistochemical analysis revealed the main transparent epithelioid cells and smooth muscle spindle cells to be HMB-45(+), smooth muscle actin(+), and melan-A (+).

Conclusion

Hepatic vascular epithelioid cell tumors are very rare mesenchymal neoplasms. Few studies have investigated this tumor in the hepatic falciform ligament; consequently, its diagnosis and the selection of an appropriate treatment and follow-up protocol are challenging. Treatment outcome remains unpredictable. Therefore, clear cell myomelanocytic tumor should be viewed as a tumor with uncertain malignant potential requiring long-term follow-up.

PEComa: morphology and genetics of a complex tumor family

Perivascular epithelioid cell tumors, or PEComas, are mesenchymal neoplasms composed of histologically and immunohistochemically distinctive epithelioid or spindle cells, which are immunoreactive for both smooth muscle and melanocytic markers. The cells in PEComas are typically arranged around blood vessels and appear to form the vessel wall, often infiltrating the smooth muscle of small- to medium-sized vessels. Periluminal cells are usually epithelioid and the more peripheral cells are spindle shaped. The cells have small, round to oval nuclei, sometimes with focal nuclear atypia, and clear to eosinophilic cytoplasm, and no counterpart normal cell has been identified. The PEComa "family" now includes angiomyolipoma, pulmonary clear cell "sugar" tumor and lymphangioleiomyomatosis, primary extrapulmonary sugar tumor, clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres, abdominopelvic sarcoma of perivascular epithelioid cells, and other tumors with similar features at various sites that are simply termed PEComa. Some PEComas occur in patients with tuberous sclerosis complex and share the genetic abnormalities. There is a behavioral spectrum from benign to frankly malignant, and histologic criteria have been proposed for assessing malignant potential. The differential diagnosis can include carcinomas, smooth muscle tumors, other clear cell neoplasms, and adipocytic tumors. PEComas constitute a genetically diverse group that includes neoplasms harboring TFE3 gene rearrangements and those with TSC2 mutations, indicating alternative tumorigenic pathways. Recent advances in therapy of malignant PEComas relate to increased knowledge of specific genetic changes and their effects on metabolic pathways that are susceptible to specific interventions. We review PEComas, emphasizing the diagnostic spectrum and recent immunohistochemical and genetic findings.

Malignant perivascular epithelioid cell tumor (PEComa) of the femur: a case report and literature review

BACKGROUND

We describe a case of malignant perivascular epithelial cell tumor (PEComa) arising primarily in the distal left femur of a 47-year-old male.

CASE PRESENTATION

The patient presented with pain accompanied by progressive swelling of his left thigh. Computed tomography (CT) scan and magnetic resonance imaging (MRI) revealed an osteolytic lesion. Curettage of the lesion was reported as a clear cell tumor with recommendation for exclusion of a metastatic clear cell carcinoma. However, thorough examinations did not find any primary site elsewhere, apart from the presence of bilateral pulmonary metastases. Evaluation of the submitted H & E slides identified a malignant PEComa which was further confirmed by subsequent immunohistochemical study.

CONCLUSIONS

The occurrence of PEComa as a primary bone lesion is extremely rare. We present here a malignant PEComa of the distal left femur, and summarize the clinicopathological characteristics of this rare entity with literature review.

VIRTUAL SLIDES

The virtual slide (s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5729035221600545 .

Malignant perivascular epithelioid cell tumor of the gallbladder: a case report and review of literature

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.