1. From the Departments of Pathology (Drs Sharma, Arora, and Sarkar), Neuroradiology (Dr Khanna), and Neurosurgery (Dr Singh), All India Institute of Medical Sciences, New Delhi, India.
2. Reprints: Chitra Sarkar, MD, Department of Pathology, All India Institute of Medical Sciences, New Delhi 110029, India (sarkarcs@hotmail.com or sarkarch@medinst.ernet.in).