This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lung Tumor, Subject name: Pathology
Azzopardi effect is seen in which of the following lung tumours? 
Select and explain. 
A. Adenocarcinoma, B. Squamous cell carcinoma, C. Small cell carcinoma, D. Large cell carcinoma
C: Small cell carcinoma
Answer: C: Small cell carcinoma 
Explanation: Microscopic features of small cell carcinoma: Small cells, that are generally smaller than three times the diameter of a small resting lymphocyte. "Salt and pepper" chromatin High mitotic count Basophilic staining of vascular walls due to encrustation by DNA from necrotic tumor cells (Azzopardi effect) is frequently present. Expression of neuroendocrine markers such as chromogranin, synaptophysin, and CD56. Electron microscopy shows dense-core neurosecretory granules.