Epithelioid Hemangioendothelioma Research Articles

Comprehensive evaluation of clinical outcomes in hepatic epithelioid hemangioendothelioma subsets: insights from SEER Database and departmental cohort analysis

BackgroundEpithelioid hemangioendothelioma (EHE), is an uncommon, intermediate-grade malignant vascular tumor that can manifest in diverse organs, including the liver, lungs, and bones. Given its unique malignancy profile and rarity, there lacks a consensus on a standardized treatment protocol for EHE, particularly for hepatic epithelioid hemangioendothelioma (HEHE). This study aims to elucidate factors influencing the clinical prognosis of EHE by analyzing data from the SEER database, complemented with insights from a departmental cohort of 9 HEHE cases. Through this, we hope to shed light on potential clinical outcomes and therapeutic strategies for HEHE.MethodsUsing SEER data from 22 registries, we analyzed 313 liver cancer patients with ICD-O-3 9130 and 9133 histology. Twelve variables were examined using Cox regression and mlr3 machine learning. Significant variables were identified and compared. Clinical data, imaging characteristics, and treatment methods of nine patients from our cohort were also presented.ResultIn univariate and multivariate Cox regression analyses, Age, Sex, Year of diagnosis, Surgery of primary site, Chemotherapy, and Median household income were closely related to survival outcomes. Among the ten survival-related machine learning models, CoxPH, Flexible, Mboost, and Gamboost stood out based on Area Under the Curve(AUC), Decision Curve Analysis(DCA), and Calibration Curve Metrics. In the feature importance analysis of these four selected models, Age and Surgery of primary site were consistently identified as the most critical factors influencing prognosis. Additionally, the clinical data of nine patients from our cohort not only demonstrated unique imaging characteristics of HEHE but also underscored the importance of surgical intervention.ConclusionFor patients with resectable HEHE, surgical treatment is currently a highly important therapeutic approach.

Auricular epithelioid hemangioendothelioma: Two cases first diagnosed as auricular pseudocyst

Auricular epithelioid hemangioendothelioma: Two cases first diagnosed as auricular pseudocyst

Long-term prognosis and treatment modalities of hepatic epithelioid hemangioendothelioma: a retrospective study of 228 patients

BackgroundHepatic epithelioid hemangioendothelioma (EHE) is an extremely rare tumour. The aim of this study was to investigate the long-term prognosis and its relationship with treatment modalities.MethodsFrom March 2014 to June 2024, a total of 234 patients with histologically confirmed hepatic EHE were treated or followed up regularly by our team. The patients’ clinical data at the time of diagnosis and initial treatment modalities were retrospectively collected. Kaplan–Meier curves were constructed to determine overall survival (OS). To explore prognostic factors and treatment outcomes, univariable and multivariable Cox proportional hazard models were developed.ResultsA total of 228 patients were ultimately included. The median age of the cohort was 41 years. For all patients, the OS of 1-, 3- and 5-year were 96.2%, 87.9% and 84.9%, respectively. For patients who underwent liver transplantation (LT), the OS of 1- and 3-year were 62.5% and 25%, respectively. No difference was found in the OS between patients who received surgical therapy and those who did not (1-year: 100% vs. 96.9%; 3-year: 90.1% vs. 91.5%; 5-year: 87.2% vs. 88.2%; P = 0.891). In the multivariable analysis, age ≥ 60 years [HR (95% CI): 4.207 (1.266–13.973), P = 0.019], the size of the largest lesion > 10 cm [HR (95% CI): 12.140 (1.419–103.872), P = 0.023] and LT [HR (95% CI): 5.502 (1.343–22.536), P = 0.018] were poor prognostic factors.ConclusionsCompared with nonsurgical therapy, surgical therapy has no advantage in terms of long-term survival. The role of LT in the management of hepatic EHE should be reevaluated. Age ≥ 60 years and the size of the largest lesion > 10 cm are poor prognostic factors.

Pseudomyogenic Hemangioendothelioma: A Case Report of a Rare Tumor with Unusual Presentation

Abstract Introduction/Objective Pseudomyogenic hemangioendothelioma (PHE) is an extremely rare neoplasm recently categorized by the World Health Organization (WHO) as an intermediate-grade vascular soft tissue tumor affecting young adults. While most documented cases exhibit local aggressiveness, we present a case with unusual presentation characterized by multiple pelvic and femoral lytic bone lesions associated with documented liver metastases. Methods/Case Report A mid-forties female presented with progressive left hip pain persisting for 2 weeks. Radiological assessments showed multiple lytic lesions in the left superior pubic ramus, right iliac wing, and left greater trochanter with associated pathologic fractures and soft tissue involvement. Additionally, multiple indeterminate hepatic and splenic hypodensities were noted. Histologic examination of the bone and liver biopsies revealed a neoplasm composed of spindled and epithelioid cells with hyperchromatic nuclei and eosinophilic cytoplasm. The neoplastic cells are arranged haphazardly and in short fascicles within a fibromyxoid stroma or sinusoidal spaces (in the liver) associated with scattered acute and chronic inflammation. Frequent mitoses are noted; however, no necrosis was identified. Tumor cells were positive for CD31, ERG, FOSB with equivocal staining for pankeratin and CK8/18. The top differential consideration was epithelioid hemangioendothelioma (EHE); however, sarcoma fusion next-generation sequencing panel exhibited features of a vascular neoplasm with WWTR1-FOSB, favoring PHE. Results (if a Case Study enter NA) NA Conclusion Pseudomyogenic hemangioendothelioma is a rare tumor that is prone for local recurrence and usually affect young adults (mean age: 30 years). Metastases are uncommon. To the best of our knowledge, we report a case of PHE with unusual presentation of early metastases to liver and possibly the spleen and highlights the complexity of PHE diagnosis.

Histology-specific clinical trial of lenvatinib and pembrolizumab in patients with sarcoma.

Survival of patients with metastatic sarcoma remains poor, and there is pressing need for new therapies. Most sarcoma subtypes are not responsive to immune checkpoint inhibition alone. Lenvatinib, a multi-receptor tyrosine kinase inhibitor targeting tumor vasculature, has immunomodulatory activity that contributes to its antitumor effects. Therefore we hypothesized that combination of lenvatinib and pembrolizumab would lead to improved clinical outcomes in patients with sarcoma. This was an open-label, single-arm study of lenvatinib and pembrolizumab in the following cohorts A: leiomyosarcoma, B: undifferentiated pleomorphic sarcoma (UPS), C: vascular sarcomas (angiosarcoma and epithelioid hemangioendothelioma), D: synovial sarcoma or malignant peripheral nerve sheath tumor (MPNST), and E: bone sarcomas (osteosarcoma and chondrosarcoma). The primary endpoint was best overall response (BOR) rate documented by RECIST v1.1 by 27 weeks in each cohort, with a threshold of ≥2 responses among 10 patients. Secondary endpoints included progression-free survival, overall survival, duration of response and safety. Forty-six patients were evaluable for the primary endpoint which was met in the UPS and MPNST/synovial cohorts (BOR rates by 27 weeks of 25% and 30%,respectively). There were 7 partial responses overall with additional responses noted in angiosarcoma and osteosarcoma. Treatment-related adverse events of any grade, and Grade 3 or higher, occurred in 50/51 (98%) and 29/51 (57%) of patients respectively. We observed durable responses in MPNST, synovial sarcoma and osteosarcoma. Patients with UPS and angiosarcoma also responded. Further exploration of this approach is warranted to confirm activity and determine optimal dosing schedules.

TFE3-Rearranged Tumors of the Kidney: An Emerging Conundrum

Background: Identical translocations involving the TFE3 gene and various partners have been found in both renal and soft tissue tumors, like alveolar soft part sarcoma (ASPSCR1), ossifying fibromyxoid tumor (PHF1), epithelioid hemangioendothelioma, and the clear cell stromal tumor of the lung (YAP1). Methods: Herein, we review in detail the clinicopathologic and molecular data of TFE3-rearranged renal tumors and propose our perspective, which may shed light on this emerging conundrum. Results: Among the kidney tumors carrying TFE3 translocations, most are morphologically heterogeneous carcinomas labeling for the tubular marker PAX8. The others are mesenchymal neoplasms known as PEComas, characterized by epithelioid cells co-expressing smooth muscle actin, cathepsin-K, melanogenesis markers, and sometimes melanin pigment deposition. Over the past 30 years, numerous TFE3 fusion partners have been identified, with ASPL/ASPSCR1, PRCC, SFPQ/PSF, and NONO being the most frequent. Conclusions: It is not well understood why similar gene fusions can give rise to renal tumors with different morpho-immunophenotypes, which may contribute to the recent disagreement regarding their classification. However, as these two entities, respectively, epithelial and mesenchymal in nature, are widely recognized by the pathology community and their clinicopathologic features well established, we overall believe it is still better to retain the names TFE3-rearranged renal cell carcinoma and TFE3-rearranged PEComa.

Clinical, histopathological, and immunophenotypic spectrum of hepatic epithelioid hemangioendothelioma: Eight years’ data of a tertiary care center from North India

BackgroundEpithelioid hemangioendothelioma (EHE) is an uncommon vascular tumor that commonly affects the liver. Hepatic EHE (HEHE) presents with variable clinical and histopathological features. We describe detailed clinico-histopathological features, differential diagnosis, and treatment outcomes of the cases of HEHE. Materials and methodsAll cases of HEHE diagnosed in our institute in the last eight years (2016-2023) were reviewed (n=8) (total 36 cases of EHE; 22.2%). The clinical features, radiology, histopathology, immunophenotype, molecular features, and treatment outcomes of all cases were evaluated. ResultsThe median age of presentation was 49.5 years with a female: male ratio of 7:1. Abdominal pain was the commonest presentation. Approximately two-third of the patients had multifocal lesions. Histopathology showed purely epithelioid, predominantly epithelioid, and predominantly spindle-cell morphology in 50%, 25%, and 25% respectively. All cases showed typical myxohyaline/ fibrous stroma and organized thrombi of the portal/ central veins. CD31 was the most commonly used immunostain with positivity in all cases. CAMTA1 break-apart FISH was positive in 75% of cases while none showed TFE3 immunopositivity. Chemotherapy was the most commonly employed therapy (n=5) followed by surgery (n=2). The median duration of follow-up was 26 months. Five patients were alive with disease (two patients ≥3 years), one patient died of sudden cardiac death, and two patients were lost to follow-up. Two patients developed metastatic disease at follow-up. ConclusionWe describe the clinico-histopathological features and differential diagnosis of HEHE. This appears to be the largest case series of HEHE from India.

S4243 Be-year-oldnd the Ordinary: Navigating a Rare Case of Hepatic Epithelioid Hemangioendothelioma

S4243 Be-year-oldnd the Ordinary: Navigating a Rare Case of Hepatic Epithelioid Hemangioendothelioma

Role of the Hippo-YAP/TAZ Pathway in Epithelioid Hemangioendothelioma and its Potential as a Therapeutic Target.

Epithelioid hemangioendothelioma (EHE) is a rare malignant vascular tumor arising from vascular endothelial cells. This study delves into the molecular mechanisms underlying EHE, with a specific focus on the Hippo-YAP/TAZ pathway. EHE is characterized molecularly by transcriptional co-activator with a PDZ-motif (TAZ)-calmodulin binding transcription activator 1 (CAMTA1) or Yes-associated protein (YAP)-transcription factor E3 (TFE3) fusions. YAP/TAZ, a transcription co-activator, binds to transcription factors and regulates gene expression. The YAP/TAZ and its upstream Hippo pathway are involved in cell proliferation and cell contact inhibition, regulating organ size and carcinogenesis. In addition to oncogenic effects, dysfunction or gene duplication of the Hippo pathway results in a poor prognosis due to epithelial-mesenchymal transformation of epithelial cells, stem cell transformation, and increased drug resistance. Notably, the TAZ-CAMTA1 fusion is specific to EHE, and genetic alterations in the Hippo pathway other than this fusion gene are absent in EHE. The TAZ-CAMTA1 fusion is a promising therapeutic target. This review summarizes recent advances in EHE, focusing on the role of the Hippo-YAP/TAZ pathway in EHE and its potential as a therapeutic target for drug development.

Management and Long-Term Outcomes of Patients With Hepatic Epithelioid Hemangioendothelioma.

Hepatic epithelioid hemangioendothelioma (HEHE) is an uncommon vascular neoplasm characterized by variable clinical behavior. Our aim was to describe the therapeutic approach for HEHE at diagnosis and define clinicopathological characteristics associated with tumor progression and long-term survival. This is a retrospective study that includes patients with HEHE who received treatment at Mayo Clinic Rochester between 1984 and 2023. Eighty patients were included in the study (median age: 44 years; 62.5% female), 24 underwent liver transplantation, 26 underwent liver resection, and 30 were managed medically. The 3-year overall survival rates were 86.7%, 80.9%, and 51.1%, respectively. Notably, 26 patients had extrahepatic metastases at the time of diagnosis, four (16.7%) in the transplantation group, four (15.4%) in the resection group, and 18 (69.2%) in the nonsurgical group. On multivariable modeling, bone metastasis was independently associated with long-term mortality (HR 6.3, p < 0.001) while lung metastasis and surgical intervention were not associated with long-term mortality (HR 0.8, p = 0.8; HR 1.1, p = 0.9, respectively). Bone metastasis emerged as a strong predictor of poor survival. Hence, aggressive surgical intervention may not be advantageous in patients with skeletal metastases but can still be offered for those with other extrahepatic metastases.

GDF-15 predicts epithelioid hemangioendothelioma aggressiveness and is down-regulated by sirolimus through ATF4/ATF5 suppression.

Epithelioid hemangioendothelioma (EHE) poses a therapeutic challenge due to limited efficacy of conventional chemotherapy in advanced cases, necessitating exploration of new treatment avenues and identification of novel aggressiveness biomarkers. This study aimed at i) utilizing an EHE patient-derived xenograft (PDX) model and its associated cell line to assess the efficacy of sirolimus and ii) analyzing two distinct patient cohorts to pinpoint circulating biomarkers of EHE aggressiveness. A PDX model and corresponding cell line were established from an advanced EHE patient, demonstrating consistency with the original tumor in terms of histomorphology, WWTR1::CAMTA1 fusion presence, and genomic and transcriptomic profiles. Two independent patient series were employed to investigate the association between Growth/Differentiation Factor 15 (GDF-15) serum levels and EHE aggressiveness. ELISA analyses on EHE cell culture medium and blood from EHE-carrying mice revealed the release of GDF-15 by EHE cells. Sirolimus exhibited markedly higher anti-tumor activity compared to doxorubicin, concurrently reducing GDF-15 expression/release both in vivo and in vitro. This reduction was attributed to the drug-induced inhibition of phosphorylation/activation of 4E-BP1 and subsequent downregulation of the GDF-15 transcription factors ATF4 and ATF5. Blood sample analyses from two independent patient series showed a significant correlation between GDF-15 and EHE aggressiveness. This study identifies GDF-15 as a novel biomarker of EHE aggressiveness and underscores the superior efficacy of sirolimus compared to doxorubicin in our experimental models. The observed inhibition of GDF-15 release by sirolimus suggests its potential as a biomarker for monitoring the drug's activity in patients.

CDK9 Inhibition by Dinaciclib Is a Therapeutic Vulnerability in Epithelioid Hemangioendothelioma.

There are no effective treatment options for patients with aggressive epithelioid hemangioendothelioma (EHE) driven by the TAZ-CAMTA1 (TC) fusion gene. Here, we aimed to understand the regulation of TC using pharmacologic tools and identify vulnerabilities that can potentially be exploited for the treatment of EHE. TC is a transcriptional coregulator; we hypothesized that compounds that reduce TC nuclear levels, either through translocation of TC to the cytoplasm, or through degradation, would render TC less oncogenic. TC localization was monitored using immunofluorescence in an EHE tumor cell line. Two target-selective libraries were used to identify small molecules that reduce TC localization in the nucleus. The ability of the shortlisted hits to affect cell viability, apoptosis, and tumorigenesis was also evaluated. Basal TC remained "immobile" in the nucleus; administration of cyclin-dependent kinase (CDK) inhibitors such as CGP60474 and dinaciclib (Dina) mobilized TC. "Mobile" TC shuttled between the nucleus and cytoplasm; however, it was eventually degraded through proteasomes. This dramatically suppressed the levels of TC-regulated transcripts and cell viability, promoted apoptosis, and reduced the area of metastatic lesions in the allograft model of EHE. We specifically identified that the inhibition of CDK9, a transcriptional CDK, destabilizes TC. The CDK inhibitor Dina exhibited antitumorigenic properties both in vitro and in vivo in EHE models. Dina has been rigorously tested in clinical trials and displayed an acceptable toxicity profile. Therefore, there is a potential therapeutic window for repurposing Dina for the treatment of EHE.

A young male with primary hepatic epithelioid hemangioendothelioma.

Epithelioid hemangioendothelioma (EHEs) is a vascular endothelial-derived tumor, which can be seen in the liver, mediastinum, lung and other parts, and most often occurs in the liver. Hepatic epithelioid hemangioendothelioma (HEHE) is rare in clinical practice. The etiology and pathogenesis of HEHE are still unclear, and it depends on imaging and pathological examination. A case of multiple space-occupying lesions in the liver was reported. The patient had no history of chronic liver disease, and was diagnosed as hepatic epithelioid hemangioendothelioma by abdominal ultrasonography，contrast-enhanced CT，and PET-CT. Partial hepatectomy and intraoperative microwave ablation were performed. Postoperative pathological diagnosis confirmed the diagnosis of hepatic epithelioid hemangioendothelioma. This case report aims to provide clinicians with ideas for the diagnosis and treatment of the disease.

Is It Time to Resist Using RECIST as a Primary Endpoint for Rare Tumor Trials?

Epithelioid hemangioendothelioma is an ultra-rare cancer driven by YAP-CAMTA1 fusion. Based on the link of the fusion to the MEK pathway, SARC33 was performed. It is a phase 2 trial examining trametinib that missed its primary objective by RECIST but demonstrated patient-reported outcome benefits in improved pain. See related article by Schuetze et al., p. 4584.

Comparison of clinical and MRI features of hepatic angiosarcoma and epithelioid hemangioendothelioma.

Differentiating hepatic epithelioid hemangioendothelioma (EHE) and angiosarcoma (AS), the two most common vascular tumors in the liver, is important due to disparities in their prognosis and treatment. We aimed to compare clinical and MRI features of the two tumors. This retrospective study included patients with pathologically-confirmed AS or EHE who underwent MRI using gadoxetate disodium between 2008 and 2023. Two radiologists independently reviewed MR images. Wilcoxon rank sum and Fisher's exact tests were used to compare clinical and imaging features. Overall survival was compared using restricted mean survival time at 3years. 32 patients with AS (18 women [56.3%]; median age, 68years) and 38 with EHE (24 women [63.2%]; 51years) were included. Patients with AS were generally older (81.3% ≥ 60years; P < 0.001), had more frequent laboratory abnormalities (P ≤ 0.018), and poorer overall survival (11.2 vs. 31.8months; P < 0.001) than those with EHE. On MRI, a large dominant mass accompanied by smaller nodules (14/32, 43.8%), often with ill-defined margins (15/32, 46.9%) was prevalent in AS; compared with nodules of similar sizes (24/38, 63.2%; P = 0.015) with well-defined margin (30/38, 78.9%; P = 0.002) in EHE. Cirrhotic appearance of the liver was more frequent in AS (62.5%, P < 0.001), along with decreased parenchymal enhancement on hepatobiliary phase (31.3%, P < 0.001) and ascites (37.5%, P = 0.010). AS frequently presented with avid enhancement of bizarrely-shaped foci, with a centrifugal enhancement pattern. In comparison, targetoid appearance was characteristic of EHE (78.9% on T2-weighted, 54.1% on diffusion-weighted, 65.8% on multiphase images) (P ≤ 0.002), with enhancement degree typically lower than that of the aorta. On hepatobiliary phase, all the AS exhibited hypointensity, while 39.5% of EHE showed targetoid appearance (P < 0.001). Patients aged ≥ 60years presenting with laboratory abnormalities, typically with a large dominant mass accompanied by smaller nodules, exhibiting avid, bizarre, and centrifugal enhancement-particularly in the cirrhotic-appearing liver-suggests the likelihood of AS over EHE.

The observational EURACAN prospective clinical registry dedicated to epithelioid hemangioendothelioma: The protocol of an international and collaborative effort on an ultra-rare entity.

Epithelioid hemangioendothelioma (EHE) is an ultra-rare sarcoma, marked by distinctive molecular and pathological features and with a variable clinical behavior. Its natural history is still partially understood, reliable prognostic and predictive factors are lacking and many questions are still open on the optimal management. In the context of EURACAN, a prospective registry specifically dedicated to EHE was developed and launched with the aim of providing, through high-quality prospective data collection, a better understanding of this disease. Registry-based cohort study including only new cases of patients with a pathological and molecularly confirmed diagnosis of EHE. To improve the understanding of EHE natural history, validate and identify new prognostic and predictive factors, clarify the activity and efficacy of currently available treatment options, describe treatment pattern. Settings and participantsIt is an hospital-based registry established in centers with expertise in EHE including adult patients with a new pathological and molecularly confirmed diagnosis of EHE starting from the 1st December 2023. The characteristics of each patient in the facility who meets the above-mentioned inclusion criteria will be collected prospectively and longitudinally with follow-up at cancer progression and / or cancer relapse or patient death. It is a secondary use of data which will be collected from the clinical records. The data collected for the registry will not entail further examinations or admissions to the facility and/or additional appointments to those normally provided for routine patient follow-up. VariablesFull details on patients and disease features, treatment and outcome will be collected, according to common clinical practice guidelines developed and shared with all the contributing centers. In addition, data on potential confounders (e.g. comorbidity; functional status etc.) will also be collected. Statistical methodsThe data analyses will include descriptive statistics and analytical analyses. Multivariable Cox's proportional hazards model and Hazard ratios (HR) for all-cause or cause-specific mortality will be used to determine independent predictors of overall survival, recurrence and progression. The registry has been joined by 21 sarcoma reference centers across EU and UK, covering 10 countries. Patients' recruitment started in December 2023. The estimated completion date is December 2033 upon agreement on the achievement of all the registry objectives. The already established collaboration and participation of EHE patient's associations involved in the project will help in promoting the registry and fostering accrual.

Clinicopathological spectrum of hepatic epithelioid hemangioendothelioma: a series from a tertiary institute

Clinicopathological spectrum of hepatic epithelioid hemangioendothelioma: a series from a tertiary institute

Implications of the Hippo Pathway Dysregulation in Uterine Leiomyosarcoma.

Uterine leiomyosarcomas (uLMS) are the most common mesenchymal tumors of the female genital tract. uLMS genetics encompass complex karyotypes with no specific molecular alterations. The Hippo pathway has been implicated in the pathogenesis of epithelioid hemangio-endotheliomas and endometrial sarcomas. Hippo pathway effectors are YAP1 and TAZ co-transcriptional factors. We studied Hippo pathway in a series of 32 uLMS patients and its association with clinicopathological parameters. Immunohistochemical analysis of YAP1 and TAZ proteins accompanied with fluorescent in situ hybridization study of YAP1 gene was performed in patient samples. Age, sex, tumor size, stage at the time of diagnosis and treatment have been analyzed. Overall survival (OS) was calculated from the time of diagnosis until death, loss of follow up or data cut-off. Hippo signaling was found to be dysregulated in 20 (62.5%) patients with uLMS. Regarding OS we detected a trend of Hippo deregulation, designating it as a positive prognostic factor. The Hippo pathway is implicated in uLMS oncogenesis, since nuclear expression of YAP1 was detected in 17 (53.1%) of the 32 patients with immunohistochemistry and YAP1 amplification was found in 8 (25%) patients.

Hepatic Epithelioid Hemangioendothelioma: A Case Report of an Extremely Rare Tumor

Epithelioid hemangioendothelioma is a very rare vascular tumour, with fewer than 500 cases described worldwide. Diagnosis is often multifocal or at an advanced stage with non-specific symptoms. Pathological examination by biopsy is crucial to confirm the diagnosis. The liver is the most frequent site of predilection, followed by the lungs and bones. The etiology of hepatic epithelioid hemangioendothelioma is poorly understood and is not linked to chronic liver disease, with a heterogeneous and unpredictable course depending on the individual. Given the rarity of this cancer, there are no established treatment standards for this type of tumor of intermediate malignancy. Surgical resection is performed in the case of unifocal disease, and orthotopic liver transplantation remains an option in the case of multifocal and/or unresectable disease, with high survival rates and disease free survival (DFS). Transcatheter arterial chemoembolization (TACE) and chemotherapy/radiotherapy regimens are other treatment possibilities. However, surveillance may be proposed for asymptomatic patients with a slow progression. We report the case of a patient followed for a multifocal EHE with pulmonary metastases, discovered following pain in the right hypochondrium. Morphological and immunohistochemical examination confirmed the diagnosis of hepatic epithelioid hemangioendothelioma. Given the moderate symptoms, surveillance was recommended for our patient with a good clinical course and radiological stability for 3 years.

Rare primary liver cancers: An EASL position paper.

In recent years, owing to advances in our understanding of hepatocarcinogenesis, rare primary liver cancers (PLCs), including combined hepatocellular-cholangiocarcinoma, fibrolamellar carcinoma, and hepatic epithelioid hemangioendothelioma have garnered increased attention. In this position paper, an international panel of experts representing oncology, hepatology, pathology, radiology, surgery, and molecular biology has summarised the available information and evidence on the pathogenesis, diagnosis, and treatment of rare PLCs. While clinical trials of systemic treatments are underway for some rare PLCs, it is evident that more research, involving national and international collaboration, is required.