What are the next steps for a patient with lymphocytosis and monocytosis?

From the Guidelines

For a patient with lymphocytosis and monocytosis, the next steps should include a comprehensive diagnostic workup to determine the underlying cause, starting with a complete history and physical examination, including careful palpation of all lymph node areas, as recommended by 1. This should be followed by additional blood tests including a complete blood count with differential, peripheral blood smear, comprehensive metabolic panel, lactate dehydrogenase levels, LDH, b2-microglobulin, bilirubin, serum–protein electrophoresis, and Coombs test, as suggested by 1. Depending on clinical suspicion, specific tests for infectious causes like EBV, CMV, HIV, and tuberculosis should be ordered. Inflammatory markers such as ESR and CRP may be helpful. If a hematologic malignancy is suspected, flow cytometry, bone marrow biopsy, and imaging studies like CT scans or abdominal ultrasound may be necessary, as recommended by 1. Some key points to consider in the diagnostic workup include:

• Careful physical examination, including lymph node palpation
• Additional blood tests, including complete blood count with differential and peripheral blood smear
• Testing for infectious causes and inflammatory markers
• Imaging studies, such as CT scans or abdominal ultrasound, if necessary Referral to a hematologist is appropriate if there are concerning features such as persistent unexplained elevations, other abnormal cell lines, or clinical symptoms like lymphadenopathy, night sweats, or weight loss. The diagnostic approach is guided by the degree of cell elevation, duration of abnormalities, and associated clinical findings, as lymphocytosis and monocytosis can result from benign reactive processes like infections or more serious conditions like leukemia or lymphoma, as discussed in 1 and 1. A comprehensive diagnostic workup, including a complete history and physical examination, additional blood tests, and imaging studies, is essential to determine the underlying cause of lymphocytosis and monocytosis, and to guide further management and treatment, as recommended by the most recent and highest quality study 1.

From the Research

Next Steps for a Patient with Lymphocytosis and Monocytosis

• The patient's laboratory results show lymphocytosis (Absolute Lymphs: 3.5 x10E3/uL) and monocytosis (Absolute Monocytes: 1.1 x10E3/uL), which may indicate an underlying hematologic disorder 2, 3.
• A bone marrow biopsy and aspiration may be necessary to further evaluate the patient's condition, as these procedures can provide valuable information for the diagnosis of hematologic malignancies and other diseases 4, 5.
• Flow cytometric analysis of the bone marrow aspirate may also be helpful in detecting bone marrow invasion and distinguishing between different etiologies of monocytosis 5, 3.
• The combination of bone marrow biopsy and flow cytometry may be the most prognostically relevant approach for detecting bone marrow involvement in patients with lymphoma 5.
• A systematic approach to the diagnosis of monocytosis, including basic studies and flow cytometry, can help distinguish between reactive and neoplastic causes of monocytosis 3.
• The patient's lymphocyte and monocyte counts should be monitored, and further testing may be necessary to determine the underlying cause of the lymphocytosis and monocytosis 2, 6.

Potential Underlying Causes

• Chronic lymphocytic leukemia (CLL) or other lymphoproliferative disorders 2
• Chronic myelomonocytic leukemia (CMML) or other myelodysplastic syndromes 3
• Reactive monocytosis due to infection, inflammation, or other non-neoplastic conditions 3
• Other hematologic malignancies, such as diffuse large B-cell lymphoma (DLBCL) 5