‘Thumbprint’ sign seen in –
**Core Concept**
The 'thumbprint' sign is a radiological feature that refers to a specific appearance of the liver or spleen on imaging studies, typically indicating the presence of a particular condition. This sign is often associated with vascular or hematological disorders.
**Why the Correct Answer is Right**
The 'thumbprint' sign is classically seen in cases of splenic infarction, which occurs due to the occlusion of the splenic artery or its branches. This results in the formation of a wedge-shaped area of necrosis within the spleen, giving it a characteristic 'thumbprint' appearance on imaging. The splenic infarction is often a consequence of a blood clot (thrombosis) that forms within the splenic artery, which can be triggered by various factors such as sickle cell disease, portal hypertension, or splenic vein thrombosis.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the 'thumbprint' sign is not typically associated with liver conditions such as cirrhosis or metastatic disease, which may present with different imaging features.
**Option B:** This option is incorrect because the 'thumbprint' sign is not characteristic of renal conditions such as pyelonephritis or renal infarction, which may present with different imaging features.
**Option C:** This option is incorrect because the 'thumbprint' sign is not typically associated with gastrointestinal conditions such as appendicitis or mesenteric ischemia, which may present with different imaging features.
**Clinical Pearl / High-Yield Fact**
The 'thumbprint' sign is a classic radiological feature that should prompt the examiner to consider splenic infarction as a possible diagnosis. It is essential to consider the patient's clinical context and other imaging findings to make an accurate diagnosis.
**Correct Answer:** C. Splenic infarction