This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
All are true regarding Hodgkin's lymphoma, except : 
Select and explain. 
A. CNS is the commonest site of involvement, B. Characteristic cell is a Reed Sternberg cell, C. Mediastinal involvement is common in nodular--sclerosis type., D. Eosinophils, plasma cells and neutrophils increase
A: CNS is the commonest site of involvement
Answer: A: CNS is the commonest site of involvement 
Explanation: Answer is A (CNS is the commonest site of involvement) CNS involvement is an uncommon feature of Hodgkins. disease CNS involvement is an uncommon feature with Hodgkins disease: This may occur as : Sudden spinal cord compression in advanced progressive disease. Headache and visual disturbance in very rare patients with intra-cranial Hodgkins disease. Reed stern berg cell is the characteristic cell in Hodgkins, and the diagnosis of Hodgkins Lymphoma is still based entirely upon histological examination & the finding of classic Reed-Sternberg cell or one of its variants is considered essential for diagnosis. Plasms cells, Eosinophils and Neutrophils are seen in the reactive background Histology in Hodgkins shows distinctive Reed Sternberg cells (few) that are admixed with variable number of Lymphocytes, plasma cells, histocytes, eosinophills neutrophils and fibroblasts. Mediastinal involvement is paicularly common with nodular sclerosis variant Ceain Distincitive Features Seen In Nodular Sclerosis Variant it is the most common variant. Q it is the only variant more common in females. Q mediastinal involvement is paicularly common. Q large Reed Sternberg cell variants - 'Lacunar cells' Q -are present on histology. it has a good prognosis Q {2nd best, following Lymphocyte predominance (best)}