Morphologic confounders and CD19 negativity in a case of hairy cell leukemia.

Main Article Content

Pulkit Rastogi
Sreejesh Sreedharanunni
Uday Yanamandra
Man Updesh Singh Sachdeva
Neelam Varma


Hairy cell leukemia, Aberrancy, Immunophenotype, CD19 negativity.


Objectives:We report a case of hairy cell leukemia (HCL) initially misdiagnosed as plasma cell dyscrasia due to various clinical, morphological and immunophenotypic confounders.

Methods and results:In a patient diagnosed of marrow plasmacytosis and serum monoclonal protein elsewhere and referred to our hospital, morphological evaluation of bone marrow aspirate smears and trephine biopsy, immunophenotyping, and molecular testing (BRAFV600E mutation) were done. Clinically, the patient was asymptomatic, bone marrow revealed plasmacytosis, mastocytosis and lymphocytosis with a few “hairy” cells. Immunophenotyping revealed features of HCL with aberrant CD10 expression and a subclone of CD19neg cells. A diagnosis of HCL with reactive plasmacytosis and mast cell hyperplasia was made and confirmed by immunophenotyping and molecular studies.

Conclusion:Hematopathologists must be aware of various confounding factors and should judiciously use flow cytometric and molecular studies for attaining a proper diagnosis of HCL. We also report a very rare immunophenotypic aberrancy (CD 19 negativity) in HCL


Download data is not yet available.

Abstract 1878
PDF Downloads 557
HTML Downloads 1130


1. Foucar K, Falini B, Catovsky D, Stein H. Hairy cell leukaemia. In: Swerdlow SH, Campo E, Harris NL, et al. eds. WHO classification of tumours of haematopoietic and lymphoid tissues. Lyon, France: IARC press ; 2008:188-190.

2. Else M, Dearden CE, Catovsky D. Long-term follow-up after purine analogue therapy in hairy cell leukaemia. Best Pract Res Clin Haematol 2015;28:217-29.

3. Johnston JB, Grever MR. Hairy Cell Leukemia. In: Greer JP, Arber DA, Glader B et al. eds. Wintrobe’s Clinical Hematology. Philadelphia; Lippincott Williams & Wilkins; 2014:4395-4443.

4. Frassoldati A, Lamparelli T, Federico M, Annino L, Capnist G, Pagnucco G, Dini E, Resegotti L, Damasio EE, Silingardi V. Hairy cell leukemia: a clinical review based on 725 cases of the Italian Cooperative Group (ICGHCL). Italian Cooperative Group for Hairy Cell Leukemia. Leuk Lymphoma 1994;13:307-16.

5. Saif MW, Greenberg BR. Multiple myeloma and hairy cell leukemia: a rare association or coincidence? Leuk Lymphoma 2001;42:1043-8.

6. Hanbali A, Alrajeh A, Rasheed W. Plasma cell leukemia mimicking hairy cell leukemia. Hematol Oncol Stem Cell Ther 2015;8:91-2.

7. Lesesve JF, Broseus J. Confusing Hairy Cells in a Case of IgG Kappa Plasma Cell Leukemia. Clin Lab 2016;62:749-50.

8. Stoimenis D, Spyridonidou C, Papaioannou N. Transient Monoclonal Gammopathy Induced by Disseminated Staphylococcus aureus Infection. Case Rep Med 2012;2012:607104.

9. Seve P, Turner R, Stankovic K, Perard L, Broussolle C. Transient monoclonal gammopathy in a patient with Bartonella quintana endocarditis. Am J Hematol 2006;81:115-7.

10. Macon WR, Kinney MC, Glick AD, Collins RD. Marrow mast cell hyperplasia in hairy cell leukemia. Mod Pathol 1993;6:695-8.

11. Ribatti D, Crivellato E, Molica S. Mast cells and angiogenesis in haematological malignancies. Leuk Res 2009;33:876-9.

12. Gülen T, Sander B, Nilsson G, Palmblad J, Sotlar K, Horny HP, Hägglund H. Systemic mastocytosis: progressive evolution of an occult disease into fatal mast cell leukemia: unique findings on an unusual hematological neoplasm. Med Oncol 2012;29:3540-6.

13. Chen YH, Tallman MS, Goolsby C, Peterson L. Immunophenotypic variations in hairy cell leukemia. Am J Clin Pathol 2006;125:251-9.

14. Ginaldi L, De Martinis M, Matutes E, Farahat N, Morilla R, Catovsky D. Levels of expression of CD19 and CD20 in chronic B cell leukaemias. J Clin Pathol 1998;51:364-9.

15. Sausville JE, Salloum RG, Sorbara L, Kingma DW, Raffeld M, Kreitman RJ, Imus PD, Venzon D, Stetler-Stevenson M. Minimal residual disease detection in hairy cell leukemia. Comparison of flow cytometric immunophenotyping with clonal analysis using consensus primer polymerase chain reaction for the heavy chain gene. Am J Clin Pathol 2003;119:213-7.