Whole Exome Sequencing Identifies Somatic Variants in an Oral Composite Hemangioendothelioma Characterized by YAP1-MAML2 Fusion

Recurrence-Free Survival in Composite Hemangioendothelioma: A Case Study and Updated Systematic Review

Background/Objectives: Composite hemangioendothelioma (CHE) is a rare vascular endothelial tumor with borderline malignancy. This study presents a case of CHE and an updated systematic review of previously reported cases, providing insights into recurrence patterns and survival outcomes. Methods: A comprehensive electronic search was conducted across PubMed, Scopus, the Cochrane Library, and Web of Science up to 31 December 2024, to identify eligible case reports. Kaplan-Meier curves were used to estimate event-free survival. Results: We report a 61-year-old man with a splenic lesion associated with weight loss and abdominal pain persisting for 1 year. Intraoperative findings revealed an enlarged spleen and multiple hepatic deposits. Splenectomy and liver biopsy revealed a well-demarcated, nodular tumor measuring 160 × 145 × 100 mm, with histological and immunohistochemical findings consistent with CHE, complicated by hepatic metastasis. Of 405 potentially eligible studies, 59 were included in the review, covering cases from 2000 to 2024, with a peak in 2020 and 2023. The median age of patients was 42 years, with the most common tumor sites being the lower extremities (30.48%), followed by the face, head, and neck (20.95%), and upper extremities (18.1%). Surgical intervention was the most common treatment (60.95%). Recurrence-free survival was observed in 42.86% of cases, while 15.24% experienced recurrence with or without metastasis. Two patients (1.90%) died from the disease. The median recurrence-free survival was 48 months (95% CI: 7.3-88.7). Conclusions: CHE exhibits significant morphological variation and can mimic other vascular tumors. Accurate diagnosis is crucial for proper prognosis and avoiding overtreatment due to misdiagnosis as more aggressive neoplasms. Patients with high-risk CHE should undergo closer surveillance to ensure timely detection of progression.

Proliferative verrucous and homogeneous Leukoplakias exhibit differential methylation patterns

OBJECTIVE

Proliferative verrucous leukoplakia (PVL) is considered a clinically distinct entity from other oral leucoplakias (OLs) due to its clinical presentation and evolution. However, molecular differences between them remain unclear. We aimed to determine whether there are methylation differences between PVL and other forms of OLs.

MATERIALS AND METHODS

Oral biopsies from 12 patients with PVL, eight patients with homogeneous leucoplakia (HL), and 10 healthy individuals were obtained for a genome-wide DNA methylation analysis via the Infinium EPIC Platform.

RESULTS

A total of 1815 differentially methylated CpGs were found between PVL and HL, with a prominent state of hypermethylation in HL patients. CpGs covered 813 genes with distinct roles, including cell adhesion, extracellular matrix organization, and cell and synaptic signaling. 43% of these genes had been previously described in cancer and associated with prognosis. We developed a multinomial logistic regression model able to differentiate HL, PVL, and control samples. The model had a cross-validated estimate of 73% and included differentially methylated cancer-related genes between the pathological conditions and the healthy donors, including ADNP, BRCA2, CDK13, GNB1, NIN, NUMB, PIK3C2B, PTK2, SHISA4, THSD7B, WWP1, and ZNF292. It also included CpGs covering differentially methylated genes in HL (MEN1 and TNRC6B) and PVL (ACOXL, ADH1B, CAMTA1, CBFA2T3, CPXM2, LRFN2, SORCS2, and SPN).

CONCLUSIONS

PVL and HL present differential methylation patterns that could be linked to their differential clinical behavior. Our findings show the potential of methylation markers and suggest novel diagnostic biomarkers.

Vascular tumors of intermediate malignancy: An update

The term "hemangioendothelioma" is used for endothelial neoplasms of intermediate malignancy and describes a group of rare neoplasms having biologic behavior falling in between that of the benign hemangiomas and fully malignant angiosarcomas. The hemangioendotheliomas fall into several specific, clinicopathologically and genetically distinct entities, specifically epithelioid hemangioendothelioma, kaposiform hemangioendothelioma, papillary intralymphatic angioendothelioma and retiform hemangioendothelioma (hobnailed hemangioendothelioma), pseudomyogenic hemangioendothelioma, composite hemangioendothelioma, and YAP1::TFE3-fused hemangioendothelioma. The clinical, morphologic, immunohistochemical, and genetic features, and the differential diagnosis of each of these rare entities are discussed in this review.

Dural composite hemangioendothelioma: The first intracranial case

Background

Composite hemangioendothelioma (CHE) is a rare, locally aggressive neoplasm of intermediate malignant potential. It is composed of a mixture of vascular tumors with a predilection for the dermis and subcutis of the extremities.

Case Description

In this report, we describe a 41-year-old man who presented with a 2-month history of headache, dizziness, and intermittent seizures. Magnetic resonance imaging showed a hemorrhagic, multilobulated, and dural-based mass with extension into the calvarium. The mass measured 10.3 × 4.8 × 4 cm along the interhemispheric fissure and encased the superior sagittal sinus. Excision was performed, and histopathologic examination revealed a heterogeneous mixture of vascular components consisting of epithelioid hemangioendothelioma, retiform hemangioendothelioma, and hemangioma. This is the first report of a primary intracranial CHE.

Conclusion

The spectrum of mesenchymal neoplasms within the cranium expands to encompass CHE.

Untying the Gordian knot of composite hemangioendothelioma: Discovery of novel fusions

Composite hemangioendothelioma is a rare, locally aggressive, and rarely metastasizing vascular neoplasm which affects both children and adults. Recently, a number of gene fusions including YAP1::MAML2, PTBP1::MAML2, and EPC1::PHC2 have been detected in a small subset of cases with or without neuroendocrine expression. Herein, we present four additional cases with novel in-frame fusions. The cohort comprises two females and two males with a wide age range at diagnosis (24-80 years). Two tumors were deep involving the right brachial plexus and mediastinum, while the remaining were superficial (right plantar foot and abdominal wall). The size ranged from 1.5 to 4.8 cm in greatest dimension. Morphologically, all tumors had an admixture of at least two architectural patterns including retiform hemangioendothelioma, hemangioma, epithelioid hemangioendothelioma, or angiosarcoma. The tumors were positive for endothelial markers CD31 (3/3), ERG (4/4), and D2-40 (1/4, focal), while SMA was expressed in 2/3 highlighting the surrounding pericytes. Synaptophysin showed immunoreactivity in 2/3 cases. One patient had a local recurrence after 40 months, while two patients had no evidence of disease 4 months post-resection. Targeted RNA sequencing detected novel in-frame fusions in each of the cases: HSPG2::FGFR1, YAP1::FOXR1, ACTB::MAML2, and ARID1B::MAML2. The two cases with neuroendocrine expression occurred as superficial lesions and harbored YAP1::FOXR1 and ARID1B::MAML2 fusions. Our study expands on the molecular spectrum of this enigmatic tumor, further enhancing our current understanding of the disease.

Composite hemangioendothelioma- report of two cases located in bone and review of the literature

BACKGROUND

Composite hemangioendothelioma (CHE) is a rare intermediate-grade vascular tumor characterized by a complex histologic component. It occasionally metastasizes, but local recurrence is not uncommon. CHE is mainly located in the extremities' distal dermis and subcutaneous soft tissues. It is rarely located in the bone. We report here two cases originally occurred in bone.

CASE PRESENTATION

The first case of CHE occurred solely on the left pubis. The second case is a patient post-resection of CHE in the manubrium sterni 10 years ago [1], who presented with multiple lesions in the left ilium and T6, T12 vertebra. All these lesions in the two cases showed osteolytic bone destruction on computed tomography (CT) scans and showed relatively high signal intensity on the fat-suppressed sequences of T2-weighted magnetic resonance (MR) images and isointense signal intensity on T1-weighted MR images. After injection of contrast agent (Gd-DTPA), the lesions showed inhomogeneous enhancement. 2-deoxy-2 [F-18] fluoro-D-glucose positron emission tomography-computed tomography (18FDG PET-CT) showed increased FDG uptake in these osteolytic bone destruction areas with SUVmax around 5.0. Both patients underwent surgery. Lesions in the left pubis and left ilium were confirmed by postoperative pathology while lesions on the vertebrae were only biopsied, not surgically resected. The first patient had no recurrence or metastasis in 5 years after surgery. The second patient had surgery recently and is still being followed up.

CONCLUSIONS

CHE occurring in bone is rarely reported. Our report provides more detailed information on the diagnosis of CHE. Given that CHE is locally aggressive and occasionally metastatic, PET-CT may be helpful in staging and follow-up.

Benign and low-grade superficial endothelial cell neoplasms in the molecular era

Vascular tumors are the most common mesenchymal neoplasms of the skin and subcutis, and they encompass a heterogeneous group with diverse clinical, histological, and molecular features, as well as biological behavior. Over the past two decades, molecular studies have enabled the identification of pathogenic recurrent genetic alterations that can be used as additional data points to support the correct classification of these lesions. The purpose of this review is to summarize the available data related to superficially located benign and low-grade vascular neoplasms and to highlight recent molecular advances with the role of surrogate immunohistochemistry to target pathogenic proteins as diagnostic biomarkers.