Epithelioid hemangioma (EH), a rare benign tumor, is documented in only a few cases in the medical literature. The complications of epithelioid hemangioma depend on the site of their presentation. If located in the eye, epithelioid hemangiomas may lead to amblyopia; in the larynx, they can cause respiratory issues; and if affecting bone, they can result in osteolytic lesions. Here, we present a case of a 40-year-old male who presented with swelling in the medial end of the right clavicle. Following clinical evaluation and a computed tomography scan, an excision biopsy was performed. The excised lesion measured 3 x 2.5 cm, and histopathological examination confirmed the finding as an epithelioid hemangioma.

UNASSIGNED: Primary hepatic epithelioid hemangioendothelioma (HEHE) is an extremely rare tumour of vascular origin with an incidence of <0.1 cases per 100,000 people worldwide.
UNASSIGNED: A 29-year-old female with the history of epigastric pain and unintentional weight loss (3 kg over six months) was referred for upper endoscopy. The examination was without visual pathological findings, but a rapid urease test was positive. First-line treatment with clarithromycin-containing triple therapy for Helicobacter pylori infection was given. After completion of eradication therapy, diffuse abdominal pain developed. An abdominal computed tomography (CT) showed multiple liver nodules. Three consecutive core liver biopsies were performed and were inconclusive. A subsequent surgical liver nodule resection was performed. Histopathology of the specimen revealed grade 2 hepatocellular carcinoma; bone scintigraphy was negative for metastasis. A multidisciplinary team (MDT) recommended giving the patient sorafenib, which was poorly tolerated. The histology was reviewed using immunohistochemistry staining at the request of the oncologist, which showed expression of CD31 and CD34. Based on clinical, morphological and immunohistochemistry findings, a diagnosis of hepatic epithelioid hemangioendothelioma was made. Based on the multidisciplinary team\'s findings, liver transplantation was indicated as the only curative treatment.
UNASSIGNED: Because of the rarity of this disease, combining clinical, radiological and histopathological methods as well as an MDT approach can help to reach the correct final diagnosis. As demonstrated in this clinical case, it is crucial to perform immunohistochemistry of a liver biopsy to confirm a HEHE diagnosis.
CONCLUSIONS: Hepatic epithelioid hemangioendothelioma is a rare vascular tumour that is often misdiagnosed and mismanaged.This case emphasises the critical importance of interdisciplinary teamwork and the use of non-invasive and invasive techniques to achieve a definitive diagnosis.

We report a case of a 55-year-old female with an asymptomatic pink-brown nodule. Histological examination demonstrated a composite haemangioendothelioma with positive synaptophysin staining.

UNASSIGNED: Only 27 cases of equine conjunctival haemangiosarcoma have been reported in the literature over the past 37 years. Out of these, 22% of cases were lost to follow-up, 52% were euthanized, and 26% survived. A scarcity of cases and information is available for this rarely seen conjunctival tumour.
UNASSIGNED: To describe the clinical features, management, and outcome of conjunctival hemangiosarcoma in seven horses in the UK.
UNASSIGNED: Optivet medical records were reviewed for equine cases seen or advised on with a histopathological diagnosis of conjunctival haemangiosarcoma between January 2013 and March 2023. Medical records were accessed for details of signalment, history, management, and follow-up. Histopathology was used to confirm the diagnosis of haemangiosarcoma and assess the surgical margins. Immunohistochemistry was performed in a minority of cases with poorly differentiated solid tumours to support vascular lineage.
UNASSIGNED: Seven eyes from seven horses (five geldings and two mares) with a mean age of 16 years and median of 18 years (range 10-21 years) met the criteria. Serosanguinous discharge was seen in six eyes. All eyes were managed surgically; 4 by exenteration and 3 by conjunctivectomy/keratectomy. Adjunctive cryotherapy was performed in two eyes. Metastatic disease in the ipsilateral parotid salivary gland, confirmed with histopathology, was seen in one horse. Surgical margins were clear in all but one eye. Solar elastosis was noted in five eyes. All horses were healthy at the last follow-up (0.2-5 years, mean 2.9 years, and median 2 years).
UNASSIGNED: Equine conjunctival haemangiosarcoma is rare. Serosanguinous ocular discharge is a common clinical sign. Early surgical excision is highly effective. Solar elastosis is a common histopathological feature, suggesting a role for UV-light in the pathogenesis.

Vascular tumors of the liver are mesenchymal lesions from endothelial cells. They range from common benign lesions such as haemangioma, intermediate tumors like Kaposi sarcoma, and perivascular epithelioid cell tumor to malignant tumors such as hepatic epithelioid hemangioendothelioma and hepatic angiosarcoma in adults. Pediatric vascular tumors of the liver also include benign, locally aggressive, borderline, and malignant masses with haemangiomas being the most common benign tumors and epithelioid hemangioendothelioma being an uncommon pediatric malignancy. The list of these lesions is completed by nodular regenerative hyperplasia, solitary fibrous tumour, and hepatic small vessel neoplasms (HSVN). Some of these tumors are uncommon and rare. This review article aimed to enumerate hepatic vascular tumors along with their imaging, histopathology, molecular findings for accurate diagnosis that can result in better management.

We present the case of a 43-year old woman with anti-U3 ribonucleoprotein antibody-positive systemic sclerosis presenting with an enlarging purple plaque on the left upper arm. The skin was not sclerotic; however, there had been a cluster of long-standing telangiectases preceding the plaque. Histology and immunohistochemistry confirmed an angiosarcoma. There are five reported cases in the literature about angiosarcoma arising in the skin of patients with systemic sclerosis; however, to our knowledge, this is the first to have arisen from non-sclerotic skin. We would urge clinicians to adopt a high index of suspicion for atypical vascular tumours presenting in patients with systemic sclerosis.

A cavernous hemangioma, well-known as vascular malformation, is present at birth, grows proportionately with the child, and does not undergo regression. Although a cavernous hemangioma has well-defined histopathological characteristics, its origin remains controversial. In the present study, we characterized the cellular heterogeneity of a cavernous hemangioma using single-cell RNA sequencing (scRNA-seq). The main contribution of the present study is that we discovered a large number of embryonic mesenchymal stem cells (MSCs) in a cavernous hemangioma and proposed that cavernous hemangiomas may originate from embryonic MSCs. Further analysis of the embryonic MSCs revealed that: 1) proinflammatory cytokines and related genes TNF, TNFSF13B, TNFRSF12A, TNFAIP6, and C1QTNF6 are significantly involved in the MSC-induced immune responses in cavernous hemangiomas; 2) UCHL1 is up-regulated in the embryonic MSC apoptosis induced by proinflammatory cytokines; 3) the UCHL1-induced apoptosis of MSCs may play an important role in the MSC-induced immune responses in cavernous hemangiomas; and 4) UCHL1 can be used as a marker gene to detect embryonic MSCs at different apoptosis stages. In addition to MSCs, ECs, macrophages, T lymphocytes and NKCs were intensively investigated, revealing the genes and pathways featured in cavernous hemangiomas. The present study revealed the origin of cavernous hemangiomas and reported the marker genes, cell types and molecular mechanisms, which are associated with the origin, formation, progression, diagnosis and therapy of cavernous hemangiomas. The better understanding of the MSC-induced immune responses in benign tumours helps to guide future investigation and treatment of embryonic MSC-caused tumours. Our findings initiated future research for the rediscovery of MSCs, cancers/tumours and the UCHL1-induced apoptosis.

Management of kaposiform haemangioendotheliomas (KHE) with Kasabach-Merritt phenomenon is challenging in young infants who are subjected to developmental pharmacokinetic changes. Sirolimus, sometimes combined with corticosteroids, can be used as an effective treatment of KHE. Simultaneously, toxicities such as interstitial pneumonitis related to the use of sirolimus may be fatal. As infants have a very low CYP3-enzyme expression at birth, which rises during ageing, we hypothesize that a reduced metabolization of sirolimus might lead to high sirolimus serum levels and low dose may be sufficient without the side effects.
A case series of 5 infants with kaposiform haemangioendothelioma with Kasabach-Merritt phenomenon was analysed retrospectively. All infants were treated with sirolimus 0.2 mg/m2 every 24 or 48 hours according to their age. Prednisone was added to the therapy for additional effect in 4 patients.
In all patients, low dose of sirolimus led to therapeutic sirolimus levels (4-6 ng/mL). All infants (aged 4 days-7 months) had a complete haematological response, without serious adverse events. In all patients, the Kasabach-Merritt phenomenon resolved, the coagulation profile normalized and tumour size reduction was seen.
Low-dose sirolimus treatment is safe for infants with kaposiform haemangioendothelioma and Kasabach-Merritt phenomenon. It is essential to realize that during the first months of life, metabolism is still developing and enzymes necessary to metabolise drugs like sirolimus still have to mature. To avoid toxic levels, the sirolimus dosage should be based on age and the associated pharmacological developments.

UNASSIGNED: To assess the safety and efficacy of rapamycin in treating children with vascular tumours and malformations.
UNASSIGNED: We performed a retrospective review at a large tertiary care paediatric centre to assess the efficacy and safety of using rapamycin to treat vascular tumours and malformations. Response to therapy was defined by patient-reported symptom improvement, radiological reduction in size of lesions, and/or improvement of laboratory parameters.
UNASSIGNED: Forty-two patients (7 with vascular tumours and 35 with vascular malformations) have been treated with rapamycin. Despite 33 of 42 patients being diagnosed in the first year of life, the median age of initiating rapamycin was 11 years. Of the 38 children treated for a minimum of 4 months, 29 (76%) exhibited a clinical response. Twenty-one patients had follow-up imaging studies and of these, 16 (76%) had radiographic decrease in lesion size. Median time to demonstration of response was 49 days. All five children with vascular tumours and all three children with vascular malformations under the age of 4 years showed a clinical response. Response rate was lower for children ≥ 4 years of age (0/2, 0% for vascular tumours; 21/28, 75% for vascular malformations). No patient experienced an infection directly related to rapamycin or discontinued rapamycin due to toxicity.
UNASSIGNED: Rapamycin is safe and efficacious in most children with select vascular tumours and malformations. Young children appear to respond better, suggesting that early initiation of rapamycin should be considered.

Vascular lesions of the hand are common and are distinct from vascular lesions elsewhere because of the terminal vascular network in this region, the frequent hand exposure to trauma and microtrauma, and the superficial location of the lesions. Vascular lesions in the hand may be secondary to local pathology, a proximal source of emboli, or systemic diseases with vascular compromise. In most cases, ischaemic conditions are investigated with Doppler ultrasonography. However, computed tomography angiography (CTA) or dynamic contrast-enhanced magnetic resonance angiography (MRA) is often necessary for treatment planning. MR imaging is frequently performed with MRA to distinguish between vascular malformations, vascular tumours, and perivascular tumours. Some vascular tumours preferentially affect the hand, such as pyogenic granulomas or spindle cell haemangiomas associated with Maffucci syndrome. Glomus tumours are the most frequent perivascular tumours of the hand. The purpose of this article is to describe the state-of-the-art acquisition protocols and illustrate the different patterns of vascular lesions and perivascular tumours of the hand.