ZHIHONG HU, MD, PhD Fellow, Department of Hematopahtology The University of Texas MD Anderson Cancer center.

ZHIHONG HU, MD, PhD

Fellow, Department of HematopahtologyThe University of Texas

MD Anderson Cancer center

CLINICAL HISTORY

• A 25-year-old man diagnosed with rheumatoid arthritis for the past 3 years

• On follow-up of a repeat CBC, significant leukocytosis with eosinophilia about 6 months

• Had an extensive workup done: negative for ova and parasites, strongyloids

• A bone marrow biopsy was completely negative, negative for BCR-ABL, JAK2 , PDGFR alpha and beta

• Echocardiogram was negative

• For his RA, treated with methotrexate• Switched to leflunomide for the past month due

to intolerance to methotrexate• Not much complaints, except for two nodules on

the right leg, and other symptoms secondary to RA (joint stiffness and swelling (small joints of his hands, elbows and wrists) in the morning that lasts more than 1 hour, which is consistent with his RA

• No good reason for his underlying eosinophilia other than his rheumatoid arthritis

CLINICAL HISTORY (cont’d)

ANCILLARY STUDIES•CBC: WBC 38.2K/L H (4.0-11.0)RBC 4.50M/L (4.50-6.00)Hgb 13.9gm/dL L (14.0-18.0)Neutrophil: 22.0% L (42.0-66.0); 8.40K/L H (1.70-7.30), Lymphocyte:15.0% L(24.0-44.0); 5.73K/L H (1.00-4.80)Monocyte: 2.0% (2.0-7.0); 0.76K/L H (0.08-0.70), Eosinophil: 61.0% H (1.0-4.0); 23.30K/L H (0.04-0.40)

•Sodium 139, potassium 4.4, chloride 104, bicarb 28, BUN 7, creatinine 0.84, glucose 47

PERIPHERAL BLOOD SMEAR

BONE MARROW BIOPSY

PROPOSED DIAGNOSIS

• Cellular (80%) bone marrow with trilineage hematopoiesis and marked eosinophilia, compatible with LYMPHOCYTE VARIANT OF HYPEREOSINOPHILIC SYNDROME

• Sub-diagnostic systemic mastocytosis

TAKE HOME MASSAGE

• Aberrant T cell population of CD3-CD4+ immunophenotype is seen in the lymphoid variant of hypereosinophilic syndrome (L-HES)

• Monoclonal TCR gamma gene arrangement can be detected in L-HES

• Sub-diagnostic systemic mastocytosis: those meeting 1-2 minor criteria for SM only