This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Clinical Aspects of Neoplasia, Subject name: Pathology
Klatskin tumor: (Repeat) 
Select and explain. 
A. Primitive neuroectodermal tumor in chest, B. Cholangiocarcinoma arising from bifurcation of bile duct, C. Lung adenocarcinoma involving apical region, D. Enterochromaffin cell tumor
B: Cholangiocarcinoma arising from bifurcation of bile duct
Answer: B: Cholangiocarcinoma arising from bifurcation of bile duct 
Explanation: Ans: B (Cholangiocarcinoma arising from bifurcation of bile duct) Ref: Benbrahim Z et al. Askin's tumor: a case report and literature review. World J Surg Oncol. 2013: 11: 10.Explanation:Cholangiocarcinoma arising from bifurcation of bile duct - Klatsin tumorLung adenocarcinoma involving apical region - Pancoast tumorAskin tumors - Primitive neuroectodermal tumors (PNET) arising from the chest wallOther named TumorsBuschke-Lowenstein tumor-- Giant condyloma acuminatumAckerman tumor - Subtype of Verrucous Carcinoma (Carcinoma cuniculatum)Grawitz tumor - Renal cell carcinomaKrukenberg tumor - Metastatic secondaries in GIT from an ovarian primaryKuttner's stumor - Sialadenitis (sialoadenitis) - Inflammation of a salivary glandPotts puffy tumor - Frontal osteomyelitis with subperiosteal abscess e:Wilms tumor - Nephroblastoma affecting children