Rare Liver Vascular Tumour Reported for the First Time in a Transplant Graft

A recently recognized vascular tumour of the liver has been documented for what appears to be the first time in a liver transplant recipient, according to a case report by Afaf Ahmad of the Health Service Executive in Dublin and colleagues at St Vincent’s University Hospital, published in the hepatology section of Frontiers in Gastroenterology. The tumour, known as hepatic small vessel neoplasm (HSVN), has only recently entered the medical literature, and the Dublin team describes the first reported instance of it arising in a liver allograft, the transplanted organ itself.

HSVN is described in the report as a vascular tumour that behaves in a largely indolent fashion, meaning it tends to follow a slow, non-aggressive course. Its malignant potential, however, remains uncertain, which places clinicians in a difficult position when deciding how aggressively to investigate and manage it. The authors highlight that this diagnostic and management challenge is particularly relevant in a transplant recipient, a setting in which such a finding has not previously been reported.

A central theme of the case report is the diagnostic challenge the tumour poses. HSVN must be separated from hepatic angiosarcoma, a malignant vascular tumour of the liver. The authors note that HSVN lacks the marked cytologic atypia, the abnormal cellular appearance under the microscope, that characterizes angiosarcoma. The distinction also rests on immunohistochemical testing: unlike hepatic angiosarcoma, HSVN does not demonstrate diffuse overexpression of the proteins p53, GLUT1, or c-Myc. These differences in cellular appearance and protein expression form the basis on which pathologists can tell the two entities apart.

The report highlights the management considerations that follow from this diagnostic picture. Because the tumour’s behaviour is indolent but its malignant potential is not fully defined, the authors present the case as an illustration of the diagnostic challenges and management considerations that arise when such a lesion is found in a liver allograft. The keywords accompanying the article, which include CMV, EBV, CT, and H&E, point to the diagnostic toolkit of imaging, histological staining, and viral screening that surrounds the evaluation of lesions in transplant patients, although the abstract itself does not report specific findings for these investigations.

The significance of the case lies in expanding the known settings in which HSVN can occur. Documenting it in an allograft adds transplant recipients to the population in which pathologists and hepatologists may need to consider the diagnosis. The authors state that all claims expressed in the article are solely those of the authors and do not necessarily represent those of their affiliated organizations or the publisher. The report was received on 2 August 2026 and accepted on 22 September 2026, and the final formatted version is set to be published as an open-access article under a Creative Commons Attribution licence.

Subject of Research: Hepatic small vessel neoplasm occurring in a liver transplant recipient

Article Title: Hepatic small vessel neoplasm, a first case report in a liver transplant recipient

Article References: Ahmad, A. A. Y., Craughwell, M., Clarke, L., Nolan, N., Dillon, A., & Galvin, Z. (2026). Hepatic small vessel neoplasm, a first case report in a liver transplant recipient. Frontiers in Gastroenterology, 5, Article 1956520. https://doi.org/10.3389/fgstr.2026.1956520

Image Credits: AI Generated

DOI: 10.3389/fgstr.2026.1956520

Keywords: hepatic small vessel neoplasm, liver transplant, vascular tumour, angiosarcoma, case report, hepatology, immunohistochemistry, liver allograft, p53, GLUT1, c-Myc, Frontiers in Gastroenterology