Differential Diagnosis for High WBC, High Neutrophil, and High HGB

Single Most Likely Diagnosis

• Chronic Myeloid Leukemia (CML) or other myeloproliferative neoplasms: These conditions often present with elevated white blood cell (WBC) counts, particularly neutrophils, and can also cause an increase in hemoglobin (HGB) levels due to associated erythrocytosis.

Other Likely Diagnoses

• Infection: Bacterial infections, in particular, can cause a significant increase in neutrophil count as part of the body's immune response. The elevated WBC and neutrophil counts are indicative of the body's attempt to fight off the infection. High HGB could be seen in chronic infections or those that stimulate erythropoiesis.
• Chronic Inflammation: Conditions like rheumatoid arthritis or other chronic inflammatory diseases can lead to elevated WBC and neutrophil counts due to the ongoing inflammatory process. Elevated HGB might be seen in conditions associated with chronic hypoxia or as a response to chronic inflammation.
• Polycythemia Vera: A myeloproliferative disorder characterized by the overproduction of red blood cells (leading to high HGB), white blood cells, and platelets. Neutrophilia is common, and the condition can also present with an elevated WBC count.

Do Not Miss Diagnoses

• Sepsis: Although sepsis can present with a wide range of white blood cell counts, a high WBC count with a left shift (indicating immature neutrophils) is a critical finding. High HGB might not be directly related but could be seen in the context of dehydration or other complicating factors. Sepsis is a medical emergency and must be promptly recognized and treated.
• Hemorrhage or Severe Blood Loss: Acute blood loss can lead to a stress response that includes the release of neutrophils and potentially an increase in HGB concentration due to hemoconcentration. It's crucial to identify and manage the source of bleeding.

Rare Diagnoses

• Primary Neutrophilia: A rare condition characterized by a persistent and unexplained increase in neutrophil count without an apparent cause such as infection or inflammation.
• Neutrophilic Leukemoid Reaction: A rare reaction that mimics leukemia but is actually a response to severe infection, inflammation, or other stressors, leading to a marked increase in WBC and neutrophil counts.
• Erythrocytosis with Secondary Neutrophilia: Certain conditions that cause an increase in red blood cell mass (erythrocytosis) might also be associated with a secondary increase in WBC and neutrophil counts, though this is less common.