INTRODUCTION: Pancreaticobiliary subtype of Periampullary carcinoma (PAC) has a 
poor prognosis in comparison to the intestinal subtype. We assessed the 
potential of cytokeratins and mucin markers to classify the sub-types of 
periampullary tumors and compared them with the survival data to identify 
markers that may predict prognosis.
METHODOLOGY: PAC tumor tissues were obtained from 94 patients undergoing 
Whipples Pancreaticoduodenectomy. Paraffin-embedded tissues were immunostained 
with cytokeratins CK7, CK20), mucins (MUC1, MUC2, MUC5Ac), and CDX2 antibodies. 
The survival status of patients was obtained as follow-up up to 5-years of 
surgery. The Receiver Operating Character Curve (ROC) analysis was used for 
detecting sensitivity and specificity. The survival data were analyzed using the 
Kaplan-Meier survival curve.
RESULTS: Tumors were initially categorized on the basis of histological 
classification as pancreaticobiliary (n = 46), intestinal (n = 35) and 
indeterminate (n = 13). Further, using immunohistochemical markers (MUC1, CK20, 
and CDX2), we gave systematic classification of IHC-PB (n = 51), IHC-Int (n = 
30) and IHC-Mixed (n = 13). The interobserver analysis showed good agreement 
between histologic and IHC type with a kappa value of 0.554. Combined expression 
of CK20, MUC1 and CDX2 accurately classify the mixed type of tumor. Overall 
survival rate and duration were 74.4% and 44.95 ± 2.29 months. Survival analysis 
for subtypes reveal, pancreaticobiliary tumors have low survival (27.9 ± 1.63 
months) than mixed type (35.5 ± 0.45 months) and intestinal-type (52.92 ± 2.18 
months). Among these, intestinal-type have better survival. Only TNM Stage III 
(tumor staging as per American Joint Committee on Cancer classification) and 
perineural invasion have been associated with predicting poor survival in PAC 
patients.
CONCLUSION: Our results suggest that the combined expression of MUC1, CK20 and 
CDX2 could serve as markers to diagnose histological inconclusive specimens as 
mixed subtype tumors.