INTRODUCTION: The workup of lymphoproliferative disorders (LPDs) involves the 
combined use of flow cytometry (FC) and immunohistochemistry (IHC). This often 
results in duplicate immunophenotypic testing and adds costs that may not be 
eligible for reimbursement based on the Medicare National Correct Coding 
Initiative. We aimed to establish a cost-effective diagnostic algorithm based on 
initial FC categorization to reduce repetitive immunophenotyping.
METHODS: We retrospectively reviewed 242 cases of suspected LPDs with concurrent 
FC and IHC testing over a 12-month period. We correlated FC with surgical 
diagnoses and evaluated the frequency of repeat IHC testing.
RESULTS: Repetitive immunophenotyping was common; overall, 85% of cases had at 
least one marker repeated. Concordant cases were significantly less likely to 
have markers repeated than discordant cases. Of concordant B cell malignancies, 
57% represented recurrent disease; however, repeat marker usage was not 
decreased as compared to new diagnoses. The most frequently repeated markers 
were CD3, CD5, CD10, and CD20.
CONCLUSIONS: We propose that in concordant cases, CD5 and CD10 should not be 
repeated by IHC; this would decrease the use of these markers by 80% and 76%, 
respectively. We developed an algorithmic approach to IHC usage that has 
improved incorporation of FC data at our institution and may reduce healthcare 
costs.