This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and breast, Subject name: Surgery
Which one of the following is not a CT feature of Adrenal adenoma ? 
Select and explain. 
A. Low attenuation, B. Homogeneous density and well defined borders, C. Enhances rapidly, contrast stays in it for relatively longer time and washes out late, D. Calcification is rare
C: Enhances rapidly, contrast stays in it for relatively longer time and washes out late
Answer: C: Enhances rapidly, contrast stays in it for relatively longer time and washes out late 
Explanation: Ref: internet CT is often the modality which identifies an adrenal mass. Founately using density is highly sensitive and specific as 70% of adrenal adenomas contain significant intracellular fat. Lipid-poor adenomas are more difficult to diagnose because the CT density increases and approach those of soft tissue. For lipid-poor lesions, the 15 minutes post contrast >60% absolute It is impoant to note that hypervascular metastases may show identical washout values, paicularly those from . An alternative diagnosis to adrenal adenoma must be considered when there is a value >120 HU on the poal venous phase, paicularly in cases with a prior history of neoplasm