Differential Diagnosis

The patient presents with left-sided abdominal discomfort, left shoulder pain, splenomegaly, and abnormal laboratory results, including leukocytosis, thrombocytosis, and mild anemia. Based on these findings, the differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis

  • Chronic Myeloid Leukemia (CML): The presence of splenomegaly, significant leukocytosis (elevated white blood cell count), and thrombocytosis (elevated platelet count) are highly suggestive of CML. Cytogenetic testing, which is pending, may reveal the Philadelphia chromosome, a hallmark of CML.

• Other Likely Diagnoses

  • Myeloproliferative Neoplasm (MPN): This category includes conditions like essential thrombocythemia and polycythemia vera. The patient's thrombocytosis and splenomegaly could be consistent with an MPN, although the significant leukocytosis is more suggestive of CML.
  • Primary Myelofibrosis: Although less likely given the absence of significant fibrosis indicators, primary myelofibrosis could present with splenomegaly and abnormalities in blood cell counts.

• Do Not Miss Diagnoses

  • Lymphoma: Although the patient does not have lymphadenopathy, lymphoma can present with splenomegaly and abnormal blood counts. It's crucial to consider lymphoma to ensure appropriate diagnosis and treatment.
  • Infectious or Inflammatory Causes: Conditions like tuberculosis or sarcoidosis can cause splenomegaly and systemic symptoms. Although less likely, these diagnoses should be considered to avoid missing a potentially treatable condition.

• Rare Diagnoses

  • Chronic Lymphocytic Leukemia (CLL): CLL is less likely in this case due to the presence of significant leukocytosis with a high platelet count and splenomegaly, which are more characteristic of myeloproliferative disorders. CLL typically presents with lymphocytosis, and while splenomegaly can occur, the combination of findings in this patient is less typical for CLL.
  • Hairy Cell Leukemia: This rare condition can cause splenomegaly and pancytopenia but is less likely given the patient's presentation and laboratory findings.
  • Other rare myeloproliferative or lymphoproliferative disorders: These could include conditions like systemic mastocytosis or large granular lymphocytic leukemia, which are less common and might present with overlapping features.