Hematology Case Study: Monocytosis in An Elderly Patient

An 81 year old presented with fatigue and not feeling too well. CBC revealed marked leukocytosis and monocytosis.

• White cell count: 85.1 K/uL (elevated)
• Hemoglobin: 8.6 g/dl (decreased)
• Platelet count: 79 K/uL ( decreased)

Review of peripheral smear revealed leukoerythroblastosis with monocytosis (19.57 K/uL) along with presence of numerous immature monocytoid cells, dysplastic myeloid precursors and 7% blasts, consistent with myelodysplastic/myeloproliferative neoplasm such as chronic myelomonocytic leukemia-1.

For further evaluation of disease progression and/or transformation to acute leukemia, bone marrow evaluation was recommended.

Diagnostic criteria for chronic myelomonocytic leukemia

1. Persistent peripheral blood monocytosis >1 K/uL
2. No Philadelphia chromosome or bcr-abl 1 fusion gene
3. No rearrangement of PDGFRA or PDGFRB
4. Fewer than 20% blasts in the blood or bone marrow**
5. Dysplasia in one or more myeloid lineages.

**Blasts include myeloblasts, monoblasts and promonocytes

Prognosis and predictive factors

Survival of patients with CMML is reported to vary from one to more than 100 months, but the median survival time in most series is 2- to 40 months. Progression to AML occurs in approximately 15-30% of cases. A number of clinical and hematological parameters, including splenomegaly, severity of anemia and degree of leukocytosis, have been reported to be important factors in predicting the course of the disease.

-Neerja Vajpayee, MD, is the director of Clinical Pathology at Oneida Health Center in Oneida, New York and is actively involved in signing out surgical pathology and cytology cases in a community setting. Previously, she was on the faculty at SUNY Upstate for several years ( 2002-2016) where she was involved in diagnostic work and medical student/resident teaching.