Hepatic small vessel neoplasm, a rare infiltrative vascular neoplasm of uncertain malignant potential

Abstract

Summary Characteristic but rare vascular neoplasms in the adult liver composed of small vessels with an infiltrative border were collected from an international group of collaborators over a 5-year period (N = 17). These tumors were termed hepatic small vessel neoplasm (HSVN), and the histologic differential diagnosis was angiosarcoma (AS). The average age of patients was 54 years (range, 24–83 years). HSVN was more common in men. The average size was 2.1 cm (range, 0.2–5.5 cm). Diagnosis was aided by immunohistochemical stains for vascular lineage (CD31, CD34, FLI-1), which were uniformly positive in HSVN. Immunohistochemical stains (p53, c-Myc, GLUT-1, and Ki-67) for possible malignant potential are suggestive of a benign/low-grade tumor. Capture-based next-generation sequencing (using an assay that targets the coding regions of more than 500 cancer genes) identified an activating hotspot GNAQ mutation in 2 of 3 (67%) tested samples, and one of these cases also had a hotspot mutation in PIK3CA. When compared with hepatic AS (n = 10) and cavernous hemangioma (n = 6), the Ki-67 proliferative index is the most helpful tool in excluding AS, which demonstrated a tumor cell proliferative index greater than 10% in all cases. Strong p53 and diffuse c-Myc staining was also significantly associated with AS but not with HSVN or cavernous hemangioma. There have been no cases with rupture/hemorrhage, disseminated intravascular coagulation, or Kasabach-Merritt syndrome. Thus far, there has been no metastasis or recurrence of HSVN, but complete resection and close clinical follow-up are recommended because the outcome remains unknown.

Recurrent GNA14 mutations in anastomosing haemangiomas

“…Mutations in the GNAQ family appear to be common among a variety of sporadic and congenital small vessel lesions. [5][6][7][8]10 Similar to our findings, mutually exclusive mutations in this family have been identified in congenital haemangiomas and capillary malformations. 5,8 Many of these distinct pathological entities have unique histological features and clinical presentations, so factors other than mutations in genes of the Gaq family probably account for these differences.…”

Combined hepatocellular‐cholangiocarcinoma with angiosarcomatoid change: A case report with immunohistochemical study

“…c-Myc, GLUT1, p53, and Ki-67 have been reported to be effective markers for distinguishing angiosarcoma from hepatic small vessel neoplasm, a more benign vascular neoplasm. 11 In this case, the angiosarcomatoid cells were positive for c-Myc on immunohistochemical staining. The expression of GLUT1 was not significantly higher in these cells than in other parts of the tumor.…”

“…Angiosarcomatoid cells diffusely expressed CD31 and factor VIII, and a small portion of angiosarcomatoid cells expressed CD34. c‐Myc, GLUT1, p53, and Ki‐67 have been reported to be effective markers for distinguishing angiosarcoma from hepatic small vessel neoplasm, a more benign vascular neoplasm . In this case, the angiosarcomatoid cells were positive for c‐Myc on immunohistochemical staining.…”

Malignant Vascular Tumors of the Liver in Adults

“…Usually, it appears as a homogeneous mass that strongly enhances in the early phases of the dynamic study, with varied enhancement patterns in the late phase. 79,80 We have recently collaborated to an international network study headed by Gill et al, 81 collecting 17 of these cases, unified under the category of "hepatic small vessel neoplasm (HSVN)," a tumor more common in adult men (mean age: 54 years), usually without comorbidities. Lewis et al 79 reported a similar case of small vessel hemangioma occurring in a patient with cirrhosis.…”

“…Strong p53 and diffuse c-Myc staining were also significantly associated with angiosarcoma, but not with HSVN or cavernous hemangioma. 81 Capture based next generation sequencing using an assay that targets the coding regions of more than 500 cancer genes identified an activating hotspot GNAQ mutation in two of three (67%) tested samples, and one of these cases also had a hotspot mutation in PIK3CA. 81 Mutations previously reported in hepatic angiosarcoma were not found in this rather small sample of cases of HSVN.…”