A 52-year-old man with known cirrhosis due to chronic hepatitis B presents with multiple vascular lesions on his chest and face. On examination, the lesions blanch completely when pressure is applied to the central spot, and refill from the center outward when the pressure is released. The structure marked **A** in the diagram is responsible for this characteristic blanching and refilling pattern. Which of the following best explains the pathophysiology of these lesions in this patient?

Explanation

## Why "Impaired hepatic metabolism of estrogen leading to estradiol accumulation and vascular dilation" is right Spider angiomas in chronic liver disease result from estrogen-mediated vascular dilation. The cirrhotic liver cannot metabolize estradiol efficiently, leading to accumulation of circulating estrogen. This excess estrogen causes dilation of the central arteriole (marked **A**) and its radiating capillary legs, producing the characteristic lesion. The central arteriole acts as the feeding vessel—when pressure is applied directly to it, blood flow ceases and the lesion blanches; upon release, blood refills from the center outward. This pathophysiology is specific to chronic liver disease and explains why spider angiomas appear in the distribution of the superior vena cava (upper body, above nipple line), where estrogen-sensitive vessels are most responsive. (Hutchison's Clinical Methods; Robbins 10e Ch 18) ## Why each distractor is wrong - **Direct portal hypertension causing mechanical shunting of blood through superficial vessels**: While portal hypertension is present in cirrhosis, it does not directly explain the estrogen-dependent vascular dilation seen in spider angiomas. Portal hypertension causes caput medusae (paraumbilical venous engorgement), not the characteristic central arteriolar dilation of spider angiomas. The blanching pattern is not explained by mechanical shunting. - **Autoimmune destruction of the dermal-epidermal junction with secondary vascular proliferation**: Spider angiomas are not autoimmune lesions and do not involve destruction of the dermal-epidermal junction. This mechanism would not produce the characteristic central feeding arteriole or the blanching-and-refill pattern on pressure. Autoimmune vasculitis presents differently (palpable purpura, systemic symptoms). - **Congenital malformation of capillary endothelium resulting in abnormal vasodilation**: Spider angiomas in cirrhosis are acquired lesions, not congenital malformations. They develop secondary to chronic liver disease and estrogen accumulation, not from developmental abnormalities. Congenital vascular malformations (e.g., Osler-Weber-Rendu) have different clinical features and do not blanch with pressure on a central feeder vessel. **High-Yield:** Spider angioma = central arteriole + blanching on central pressure + upper body distribution + estrogen-mediated in cirrhosis (impaired hepatic estrogen metabolism). [cite: Hutchison's Clinical Methods; Robbins 10e Ch 18]