A 34-year-old woman comes to the office due to vague abdominal pain over the past several months. She has no significant past medical history. The patient does not use tobacco or alcohol. Temperature is 36.7 C (98.1 F). On physical examination, right upper quadrant fullness is present. Abdominal imaging reveals a dense liver mass. Angiography shows a well-demarcated, highly vascularized tumor surrounded by normal liver parenchyma. Which of the following substances most likely contributed the most to blood vessel development in this patient's tumor?

Question

A 34-year-old woman comes to the office due to vague abdominal pain over the past several months.  She has no significant past medical history.  The patient does not use tobacco or alcohol.  Temperature is 36.7 C (98.1 F).  On physical examination, right upper quadrant fullness is present.  Abdominal imaging reveals a dense liver mass.  Angiography shows a well-demarcated, highly vascularized tumor surrounded by normal liver parenchyma.  Which of the following substances most likely contributed the most to blood vessel development in this patient's tumor?

Quizplus · Accepted Answer

This patient has a highly vascularized liver tumor, possibly a benign hepatic hemangioma. Many cases are discovered incidentally. Angiogenesis (blood vessel formation) is predominantly driven by the following 2 substances: However, the laminin in basement membranes may pose a physical barrier to the sprouting of new blood vessels. (Choice A) Epidermal growth factor (EGF), not to be confused with VEGF, has a mitogenic influence on epithelial cells, hepatocytes, and fibroblasts. EGF does not appear to play as important a role in angiogenesis as VEGF or FGF-2. (Choice C) Insulin-like growth factor 1 (IGF-1), or somatomedin C, is synthesized predominantly by growth hormone-influenced hepatocytes and serves to stimulate cell growth and multiplication. IGF-1 does not appear to directly stimulate angiogenesis, but it can indirectly promote it by encouraging cell growth. (Choices D and E) Although the proinflammatory nature of interleukin-1 (IL-1) can induce the release of other proinflammatory cytokines that trigger cellular VEGF expression, IL-1 does not appear to directly stimulate angiogenesis. Similarly, although interferon-γ can indirectly promote neovascularization through activation of macrophages (can release VEGF), it does not appear to directly stimulate angiogenesis. Educational objective: The key growth factors that promote angiogenesis in neoplastic and granulation tissue are vascular endothelial growth factor (VEGF) and fibroblast growth factor. Proinflammatory cytokines (eg, interleukin-1, interferon-γ) can indirectly promote angiogenesis through increased VEGF expression. The laminin in basement membranes may pose a physical barrier to the sprouting of new blood vessels.

A 34-Year-Old Woman Comes to the Office Due to Vague