The heterogeneity of Epithelioid Hemangioendothelioma (EHE): A case series and review of the literature with emphasis on treatment options

Nab-Paclitaxel Based Chemotherapy in the Treatment of Advanced Epithelioid Hemangioendothelioma: A Single-Institution Experience

Objective

To evaluate the clinical efficacy of nab-paclitaxel based chemotherapy in the treatment of advanced epithelioid hemangioendothelioma (EHE).

Methods

Since March 2022, chemotherapy has been recommended for patients with advanced EHE characterized by large tumors (liver tumors > 10 cm or tumors in other organs > 3 cm), rapid tumor progression, severe symptoms, serosal effusion, and treatment failure. Two chemotherapy regimens were administered: nab-paclitaxel plus bevacizumab and nab-paclitaxel plus sirolimus. Clinical data and outcomes were retrospectively analyzed.

Results

From March 2022 to August 2024, 21 patients with histologically confirmed EHE who received nab-paclitaxel based chemotherapy were included. At baseline, 18 patients (85.7%) presented with tumor-related symptoms, and serosal effusion was detected in 12 patients (57.1%). Among patients with hepatic EHE, six (28.6%) had tumors > 10 cm, while six (28.6%) with EHE at other sites had tumors > 3 cm. Partial response and stable disease were achieved in 5 (23.8%) and 12 (57.1%) patients, respectively, resulting in a disease control rate of 80.9%. Symptom relief was observed in 15 of 18 patients (83.3%), and decreased serosal effusion was noted in 6 of 12 patients (50.0%). The 1- and 2-year progression-free survival rates were 50.7% and 13.5%, respectively, while the 1- and 2-year overall survival rates were 70.6% and 51.5%, respectively.

Conclusion

Nab-paclitaxel based chemotherapy may offer an effective treatment option for patients with advanced EHE exhibiting adverse prognostic factors. However, further clinical trials are required to confirm its efficacy.

CAMTA1-immunonegative epithelioid hemangioendotheliomas of the liver: a clinicopathological and molecular analysis of seven cases

Background

Epithelioid hemangioendothelioma (EHE) is a rare malignant vascular tumor. Most EHEs (>90%) cases harbor WWTR1::CAMTA1 fusion gene, and CAMTA1 immunohistochemistry (IHC) is a highly sensitive and specific tool for EHE diagnosis. However, there exist CAMTA1-immunonegative cases, the majority of which harbor YAP1::TFE3 fusion, with a few cases having more rare fusions. Liver is one of the most common sites of EHE, where the CAMTA1 subtype dominates, and the other variants are extremely rare. Hence, we focused on the hepatic CAMTA1-immunonegative EHEs to analyze the clinicopathological and molecular features of these peculiar cases.

Methods

The SNOMED search of the hospital pathology files between January 2016 to November 2023 identified 57 hepatic EHEs and 7 cases were CAMTA1-immunonegative. Fluorescence in situ hybridization (FISH), next generation sequencing (NGS) and Sanger sequencing were performed to identify the genetic change of the 7 cases.

Results

This series included 3 females and 4 males, aged from 33 to 64 years. All the 7 cases were negative for CAMTA1 IHC. Four cases were positive for TFE3 IHC and exhibited YAP1::TFE3 fusion. Another 3 cases were also negative for TFE3, while WWTR1::CAMTA1 fusion were detected by NGS in 1 case and demonstrated by FISH in all the 3 cases. Morphologically, among the 4 TFE3 rearrangement cases, 3 cases showed the TFE3-sutype morphologic appearance, while the histology of 1 case was similar to that of CAMTA1- subtype. In the 3 CAMTA1-rearranged lesions, 2 cases had classic EHE morphology, and 1 case exhibited atypical histology, with higher atypia and well-formed vessels. Surgical resection was performed on five cases and two cases were biopsied and received chemotherapy. Follow-up information was available in 6 patients (median 46 months), including 4 patients were alive without disease and 2 patients were alive with disease.

Conclusion

Our study reported 7 CAMTA1-immunonegative hepatic EHEs and most of them were TFE3-rearranged EHEs with morphology variation. Moreover, there does exist the CAMTA1-immunonegative but CAMTA1-rearranged EHE cases. Therefore, the diagnosis of EHE should be based on morphology, combined with CAMTA1 and TFE3 IHC, and if necessary, supplemented by genetic analysis including FISH and NGS, to establish correct diagnosis.

Epithelioid hemangioendothelioma prognosis and outcome: report of two challenging cases

BACKGROUND

Epithelioid hemangioendothelioma (EHE) is an uncommon vascular malignancy characterized by an unpredictable clinical course and a high potential for recurrence and metastasis. The lack of standard treatment guidelines, coupled with the tumor's inconsistent response to available treatments, complicates the management of EHE and leads to widely varying patient prognoses.

CASE PRESENTATION

We report two cases of EHE with distinct presentations reflecting the site of involvement. The first case involved a patient with pulmonary EHE who initially benefited from complete surgical resection of the tumor after chemotherapy. However, the patient experienced two episodes of metastatic recurrence, resistant to further surgical and chemotherapeutic interventions, ultimately leading to the patient's death forty-two months after the diagnosis. The second case presented with a mediastinal EHE involving the para-esophageal area. Partial tumor resection was achieved but postoperative imaging revealed extensive metastasis and pleural effusion. Despite additional treatments, the disease progressed rapidly, and the patient passed away fourteen months following the initial diagnosis.

CONCLUSIONS

The optimal therapeutic approach for EHE remains controversial due to its unpredictable treatment response, particularly in recurrent or metastatic cases. Therapeutic investigations are needed to establish evidence-based guidelines that can address treatment challenges and ensure the best possible outcome for each patient.

Epithelioid Hemangioendothelioma as a Dangerous, Easy to Miss, and Nearly Impossible to Clinically Diagnose Condition: Case Report

Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor with metastatic potential. EHE can have single- or multiorgan involvement, with presentations ranging from asymptomatic disease to pain and systemic symptoms. The extremely heterogeneous clinical presentation and disease progression complicates EHE diagnosis and management. We present the case of a 24-year-old woman with two periauricular erythematous papules, leading to the discovery of metastatic EHE through routine biopsy, despite a noncontributory medical history. Histology revealed the dermal proliferation of epithelioid cells and vacuoles containing red blood cells. Immunohistochemistry markers consistent with EHE solidified the diagnosis. Although extremely rare, prompt diagnosis of EHE is essential for informed decision-making and favorable outcomes. Key clinical and histopathological findings are highlighted to aid dermatologists in diagnosing and managing this uncommon condition.

Image-Guided Thermal Ablation for Hepatic Epithelioid Hemangioendothelioma: A Multicenter Experience

PURPOSE

To investigate the feasibility, safety, and clinical outcomes of image-guided thermal ablation in patients with hepatic epithelioid hemangioendothelioma (HEHE).

MATERIALS AND METHODS

This was a multicenter retrospective investigation of 18 patients (43.9 years [SD ± 14.8]; 6 men) who underwent image-guided thermal ablation for HEHE between January 2013 and February 2023. A total of 31 ablation sessions (24 involving microwave ablation and 7 involving radiofrequency ablation) were evaluated. The rates of technical success, adverse events, and outcomes were assessed. The Kaplan‒Meier method was used to estimate progression-free survival (PFS) and overall survival (OS) rates. The risk factors affecting PFS were investigated using Cox proportional hazard regression analysis.

RESULTS

The technical success rate was 93.5% (29/31). No major adverse events occurred. Local tumor progression occurred after 2 sessions (6.5%, 2/31), and intrahepatic distant metastasis occurred after 16 sessions (51.6%, 16/31). During the medium follow-up time of 37.2 months (range, 3-117 months), the OS and PFS rates were 87.6% and 62.2%, respectively, at 1 year; 75.5% and 37.4%, respectively, at 3 years; and 75.5% and 37.4%, respectively, at 5 years. The median OS and PFS were 90.5 months (95% CI: 68.1-112.8) and 23.8 months (95% CI: 15.4-32.2), respectively. According to the multivariate analysis, a larger tumor size (P = .026) was associated with shorter PFS.

CONCLUSIONS

Image-guided thermal ablation is a feasible and safe treatment option for patients with HEHE that resulted in local tumor control and a favorable long-term prognosis.

Metastatic Epithelioid Hemangioendothelioma of the Bone: A Case Report and Literature Review

Epithelioid hemangioendothelioma (EHE) is an extremely rare vascular tumor, which can pose a diagnostic dilemma. It affects women more than men and is mainly found in the liver, lung, and bone. To date, there are no known predisposing factors. Limited data are available on the management of EHE at metastatic stages. The only optimal treatments to prevent metastatic dissemination are surgical resection and amputation in addition to radiotherapy at early stages. The oncologist in this rare entity plays an important role in the guided and standardized management of this disease, especially for advanced stages. In this article, we report the case of a 74-year-old patient admitted with swelling on the outer aspect of the right calf associated with pain and total functional impairment of the limb. The diagnosis favored a high-risk vascular tumor resembling EHE, confirmed by bone (tibia) and soft tissue biopsy. The patient underwent staging investigations, revealing diffuse metastases to the liver, bones, and lungs. The objective of this article is to advocate for oncological intervention in this entity, particularly in the advanced stages of the disease. Despite its rarity, the advancement of clinical trials and therapeutic recommendations remains crucial for optimal treatment.

The oncogenic fusion protein TAZ::CAMTA1 promotes genomic instability and senescence through hypertranscription

TAZ::CAMTA1 is a fusion protein found in over 90% of Epithelioid Hemangioendothelioma (EHE), a rare vascular sarcoma with an unpredictable disease course. To date, how TAZ::CAMTA1 initiates tumour formation remains unexplained. To study the oncogenic mechanism leading to EHE initiation, we developed a model system whereby TAZ::CAMTA1 expression is induced by doxycycline in primary endothelial cells. Using this model, we establish that upon TAZ::CAMTA1 expression endothelial cells rapidly enter a hypertranscription state, triggering considerable DNA damage. As a result, TC-expressing cells become trapped in S phase. Additionally, TAZ::CAMTA1-expressing endothelial cells have impaired homologous recombination, as shown by reduced BRCA1 and RAD51 foci formation. Consequently, the DNA damage remains unrepaired and TAZ::CAMTA1-expressing cells enter senescence. Knockout of Cdkn2a, the most common secondary mutation found in EHE, allows senescence bypass and uncontrolled growth. Together, this provides a mechanistic explanation for the clinical course of EHE and offers novel insight into therapeutic options.

Epithelioid hemangio-endothelioma (EHE) in NETSARC: The nationwide series of 267 patients over 12 years

EPITHELIOID HEMANGIOENDOTHELIOMA

A NATIONWIDE STUDY: Epithelioid hemangioendothelioma (EHE) is an ultrarare sarcoma whose natural history and treatment is not well defined. We report on the presentation and outcome of 267 patients with EHE in the NETSARC+ network since 2010 in France.

PATIENTS AND METHODS

NETSARC (netsarc.org) is a network of 26 reference sarcoma centres with specialised multidisciplinary tumour boards (MDTB), funded by the French National Cancer Institute (NCI), Institut National du Cancer (INCA). Since 2010, presentation to an MDTB and second pathological review are mandatory for sarcoma patients. Patients' characteristics are collected in a nationwide database regularly monitored with stable incidence since 2013. The characteristics of patients with EHE at diagnosis are presented as well as progression-free survival (PFS), overall survival (OS), and outcome under treatment.

RESULTS

Two hundred and sixty-seven patients with EHE were included in the NETSARC+ database since 2010. Median age in the series was 51 (range 10-90) years, 58% were women. Median tumour size was 37 mm (4-220). Forty-eight percent, 42%, and 10% were visceral, soft parts, or bone primaries. The most frequent sites were liver (28%), lung (13%). 40% were reported to have systemic (i.e. multifocal or metastatic disease) at diagnosis. With a median follow-up of 20 months, OS and PFS rates at 24 months were 82% and 67%, with 10-year projected OS and PFS of 62% and 21% respectively. Male and M+ patients at diagnosis had a significantly worse OS, but not PFS. Local treatment was associated with a favourable survival in localised but not in patients with advanced stage at diagnosis. For 23 patients receiving medical treatment, PFS and OS were 50.2% and 33.2% at 60 months were respectively.

CONCLUSIONS

EHE is a frequently metastatic sarcoma at diagnosis with a unique natural history. This study shows in a nationwide series over 12 years that most patients progressed but are still alive at 10 years, both in localised and metastatic stages.

18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in a Rare Case of Epithelioid Hemangioendothelioma - A Diagnostic Challenge

Our case highlights the 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan findings in a rare case of biopsy-proven epithelioid hemangioendothelioma (EHE) in a 66-year-old woman with multi-organ involvement (lung, liver, and bone) who was subsequently treated with palliative radiation therapy and oral pazopanib. Furthermore, follow-up 18F-FDG PET/CT findings are detailed. EHE is a rare malignant vascular neoplasm (<1% of all vascular tumors) with an epithelioid and histiocytoid appearance arising from the vascular endothelial and preendothelial cells.

Prognostic Factors in Epithelioid Hemangioendothelioma: Analysis of a Nationwide Molecularly/Immunohistochemically Confirmed Cohort of 57 Cases

Epithelioid hemangioendothelioma (EHE) is an extremely rare vascular sarcoma with variable aggressive clinical behavior. In this retrospective study, we aimed to investigate prognostic factors based on clinicopathologic findings in a molecularly/immunohistochemically confirmed nationwide multicenter cohort of 57 EHE cases. Patients had unifocal disease (n = 29), multifocal disease (n = 5), lymph node metastasis (n = 8) and/or distant metastasis (n = 15) at the time of diagnosis. The overall survival rate was 71.4% at 1 year and 50.7% at 5 years. Survival did not correlate with sex, age or histopathological parameters. No survival differences were observed between multifocal and metastatic disease, suggesting that multifocality represents early metastases and treatment options are limited in comparison to unifocal disease. In unifocal tumors, survival could be predicted using the risk stratification model of Shibayama et al., dividing the cases into low- (n = 4), intermediate- (n = 15) and high- (n = 3) risk groups. No clinical or histopathological parameters were associated with progressive unifocal disease course. Lymph node metastases at the time of diagnosis occurred in 14.0% of the cases and were mainly associated with tumor localization in the head and neck area, proposing lymph node dissection. In conclusion, our results demonstrate the aggressive behavior of EHE, emphasize the prognostic value of a previously described risk stratification model and may provide new insights regarding tumor focality, therapeutic strategies and prognosis.

Successful chemotherapy with continuous immunotherapy for primary pulmonary endovascular epithelioid hemangioendothelioma: A case report

RATIONALE

Epithelioid hemangioendothelioma (EHE) is a rare, low to moderate-grade malignancy, even less in pulmonary endovascular neoplasm. Patients with pulmonary EHE have no optimal treatment, resulting in poor prognoses.

PATIENT CONCERNS

We reported a 42-year-old man with multiple mild metabolic uptakes in pulmonary endovascular filling defect with a maximum standardized uptake value of 4.5 by 18-fluorodeoxyglucose/fibroblast associated protein inhibitor-positron emission tomography/ computed tomography. Anticoagulant treatment was not effective with the diagnosis of acute pulmonary embolism.

DIAGNOSES

A primary endovascular EHE pulmonary endovascular epithelioid hemangioendothelioma was diagnosed by endovascular biopsy with positive stains for molecular CD31, CD34 and CAMTA1, and it had low proliferative capacity characterized by Ki-67 of 5%. The mutation gene MSH2 (p.Y656 in exon 12) (mutation abundance of 0.07%) from peripheral blood indicates the potential benefit of an immune checkpoint inhibitor, pembrolizumab.

INTERVENTIONS AND OUTCOMES

The patient was treated with tri-weekly paclitaxel (175mg/m2) and carboplatin (AUC 5) chemotherapy regimen. He exerted a remarkable response after 5 cycles (21 days per cycle) and Pembrolizumab (200mg once monthly) as maintenance treatment.

LESSONS

This case highlights the diagnostic challenge of differentiating endovascular lesions and optimal therapy for pulmonary EHE. Importantly, it indicated that the mutation gene MSH2 (p.Y656) might influence the pathogenesis of EHE.

A Case Report of Rare Vocal Cord Hemangioendothelioma in a Paediatric Larynx

Hemangioendothelioma (HEM) is a vascular tumour which is locally aggressive with a low-grade malignant potential. We present a rare case of HEM arising from the vocal cord of a 10-year-old female child. Video laryngoscopy clearly showed a large vocal cord polyp-like mass attached to middle one-third of left cord. Histopathological examination showed fragments of tissue with a neoplasm composed of spindle cells arranged diffusely admixed with numerous small vascular channels. These specific cells were positive for CD31, CD34, vimentin and ERG. Flexiblescopy and narrow band imaging were performed 3 weeks after surgery which showed no residual mass. Treatment of HEM is hampered by lack of proper guidelines and protocol. In this case of localized vocal cord lesion, a wide excision with regular follow up is considered ideal.

Establishment and Validation of a Nomogram Prognostic Model for Epithelioid Hemangioendothelioma

Background. Epithelioid hemangioendothelioma (EHE) is an ultrarare vascular sarcoma. At present, the epidemiological and clinical characteristics and prognostic factors are still unclear. Our study attempted to describe clinical features, investigate the prognostic indicators, and establish the nomogram prediction model based on the Surveillance, Epidemiology, and End Results (SEER) database for EHE patients. Methods. The patients diagnosed with EHE from 1986 to 2018 were collected from the SEER database and were randomly divided into a training group and a validation group at a ratio of 7 : 3. The Cox proportional hazard models were used to determine the independent factors affecting prognosis and establish a nomogram prognostic model to predict the survival rates for patients with EHE. The accuracy and discriminative ability of the model were measured using the concordance index, receiver operating characteristic curves, and calibration curves. The clinical applicability and application value of the model were evaluated by decision curve analysis. Results. The overall age-adjusted incidence of EHE was 0.31 patients per 1,000,000 individuals, with a statistically significant difference per year. Overall survival at 1, 5, and 10 years for all patients was 76.5%, 57.4%, and 48.2%, respectively. Multivariate Cox regression analysis identified age, tumour stage, degree of tissue differentiation, surgical treatment, chemotherapy, and radiotherapy as independent factors affecting prognosis ( $P<0.05$ ). The C-index values for our nomogram model of training group and validation group were 0.752 and 0.753, respectively. The calibration curve was in good agreement with the actual observation results, suggesting that the prediction model has good accuracy. The decision curve analysis indicated a relatively large net benefit. Conclusions. The nomogram model may play an important role in predicting the survival rate for EHE patients, with good concordance and accuracy, and can be applied in clinical practice.