Differential Diagnosis

The patient's presentation of left-sided abdominal discomfort, left shoulder pain, splenomegaly, and abnormal laboratory results suggests a hematologic disorder. The following differential diagnoses are considered:

• Single most likely diagnosis
  • Chronic Myeloid Leukemia (CML): The patient's splenomegaly, elevated leukocyte count, and thrombocytosis are highly suggestive of CML. The pending cytogenetic testing will likely reveal the presence of the Philadelphia chromosome, which is characteristic of CML.
• Other Likely diagnoses
  • Myeloproliferative Neoplasm (MPN): The patient's splenomegaly, elevated leukocyte count, and thrombocytosis could also be indicative of other MPNs, such as essential thrombocythemia or polycythemia vera.
  • Lymphoproliferative Disorder: Although less likely, the patient's splenomegaly and elevated leukocyte count could also be seen in lymphoproliferative disorders, such as chronic lymphocytic leukemia (CLL) or lymphoma.
• Do Not Miss
  • Splenetic Infarction or Rupture: Although the patient's spleen is described as non-tender, it is essential to consider the possibility of splenic infarction or rupture, especially given the patient's history of smoking and potential for thrombocytosis.
  • Infectious or Inflammatory Causes: It is crucial to rule out infectious or inflammatory causes of splenomegaly, such as endocarditis, abscess, or autoimmune disorders, although the patient's presentation and laboratory results make these less likely.
• Rare diagnoses
  • Primary Myelofibrosis: This rare MPN could present with splenomegaly and abnormal laboratory results, although it is less likely given the patient's lack of other characteristic features, such as bone marrow fibrosis.
  • Hairy Cell Leukemia: This rare lymphoproliferative disorder could present with splenomegaly and pancytopenia, although it is less likely given the patient's elevated leukocyte count and thrombocytosis.