Differential Diagnosis
The patient presents with left-sided abdominal pain, thrombocytosis (elevated platelet count), iron deficiency anemia, and specific findings on CT scan including wall thickening in the proximal ascending colon, prostate enlargement, a possible splenic infarction, and secondary infection. Considering these findings, the differential diagnoses can be categorized as follows:
Single Most Likely Diagnosis
- Colorectal Cancer: The combination of iron deficiency anemia, thrombocytosis, and wall thickening in the proximal ascending colon on CT scan strongly suggests a malignancy, with colorectal cancer being a leading consideration. The anemia could be due to chronic blood loss from the tumor, and the thrombocytosis could be a reactive response to the malignancy.
Other Likely Diagnoses
- Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis could explain the colon wall thickening and the patient's symptoms. However, the presence of thrombocytosis and specific findings like splenic infarction might be less typical.
- Diverticulitis: Although more common on the left side, diverticulitis could cause abdominal pain and wall thickening. The presence of other findings like prostate enlargement and splenic infarction would be less directly related.
- Prostate Cancer: The marked enlargement of the prostate with hypertrophy extending into the urinary bladder base could suggest prostate cancer, especially in the context of the patient's age and gender. However, this would not directly explain the colon findings or the splenic infarction.
Do Not Miss Diagnoses
- Sepsis: Given the possible secondary infection in the spleen, sepsis is a critical diagnosis not to miss, as it can be life-threatening and requires immediate intervention.
- Bleeding Disorder: Although less likely given the other findings, a bleeding disorder could explain the iron deficiency anemia. However, the thrombocytosis and other imaging findings would need alternative explanations.
- Splenic Artery Aneurysm or Other Vascular Issues: These could lead to splenic infarction and have significant implications if ruptured. The presence of thrombocytosis might suggest a myeloproliferative disorder, which increases the risk of thrombotic events.
Rare Diagnoses
- Myeloproliferative Neoplasm (MPN): The significantly elevated platelet count could suggest an MPN like essential thrombocythemia. While this could explain the thrombocytosis and potentially the splenic infarction, it would be a less common diagnosis to consider first without other supporting evidence.
- Systemic Vasculitis: Conditions like polyarteritis nodosa could potentially explain the splenic infarction and other systemic findings, but this would be a less common diagnosis and typically presents with a broader range of systemic symptoms.