What is the diagnosis for a patient presenting with leukocytosis (White Blood Cell count of 13.4), mild anemia (Red Blood Cell count of 3.94, hemoglobin of 13.1, hematocrit of 38.7), macrocytosis (Mean Corpuscular Volume of 98.2), elevated Blood Urea Nitrogen (BUN) to creatinine ratio (27.5), and complaints of chest pain exacerbated by deep breathing, accompanied by diarrhea, nausea, and normal troponin levels (0.01) for 3 days?

Differential Diagnosis

• Single Most Likely Diagnosis
  • Pulmonary Embolism (PE): The patient's complaint of chest pain worsening with deep breaths (pleuritic chest pain) and elevated D-dimer (0.30) are suggestive of a pulmonary embolism. Although the D-dimer is not significantly elevated, it is still a consideration given the clinical presentation. The patient's elevated WBC (13.4) could also indicate a response to a pulmonary embolism.
• Other Likely Diagnoses
  • Pneumonia: The patient's symptoms of chest pain, diarrhea, nausea, and elevated WBC (13.4) could be indicative of pneumonia, especially if the chest pain is pleuritic in nature.
  • Gastroenteritis: The patient's complaints of diarrhea and nausea for 3 days could suggest a gastrointestinal infection, which could also lead to dehydration and potentially explain the elevated BUN (25) and BUN/creatinine ratio (27.5).
  • Acute Coronary Syndrome: Although the troponin is very low (0.01), it is not entirely negative, and the patient's complaint of chest pain warrants consideration of acute coronary syndrome, especially if the pain is not typically pleuritic.
• Do Not Miss Diagnoses
  • Aortic Dissection: This is a life-threatening condition that can present with chest pain and would be a catastrophic miss. The fact that the pain worsens with deep breaths is more suggestive of pulmonary issues, but aortic dissection should always be considered with chest pain.
  • Pulmonary Embolism with Septic Emboli: Given the elevated WBC and symptoms that could suggest an infection, the possibility of septic emboli to the lungs should be considered, especially if there's a source of infection.
  • Cardiac Tamponade: Although less likely given the information, cardiac tamponade can present with chest pain and is a life-threatening condition that requires immediate intervention.
• Rare Diagnoses
  • Eosinophilic Pneumonia: Given the elevated WBC and the presence of chest pain, especially if there's an eosinophilic predominance, eosinophilic pneumonia could be considered, though it's less common.
  • Lymphoma or Leukemia: These conditions can present with a wide range of symptoms including chest pain, diarrhea, and nausea, but would be less likely without other specific findings such as significant lymphadenopathy or a more pronounced impact on blood cell counts.
  • Pneumocystis jirovecii Pneumonia: Typically seen in immunocompromised patients, this could be a consideration if the patient has a history of immunosuppression, but it would be less likely without such a history.