Differential Diagnosis for 64M with Hemopurulent Exudate from Anal Cleft
Single Most Likely Diagnosis
- Chronic Presacral Sinus or Fistula: Given the patient's history of laparoscopic extralevator abdominoperineal resection (APR) in 2015 and perianal sinus excision in 2019, the most likely diagnosis is a chronic presacral sinus or fistula. The presence of hemopurulent exudate from the anal cleft suggests an ongoing infectious process, which is consistent with a complication from previous surgeries.
Other Likely Diagnoses
- Anal Fistula: An anal fistula could be a cause of the hemopurulent exudate, especially given the patient's surgical history. Fistulas can be a complication of both APR and perianal sinus excision.
- Perianal Abscess: Although the patient has had perianal sinus excision, a new perianal abscess could form, leading to hemopurulent discharge.
- Rectal Prolapse or Mucosal Protrusion: Post-surgical changes could lead to rectal mucosal prolapse or protrusion, causing irritation and potentially leading to discharge.
Do Not Miss Diagnoses
- Malignancy (e.g., Recurrence of Rectal Cancer): Given the patient's history of APR, which is often performed for rectal cancer, it is crucial not to miss a potential recurrence. Malignancies can cause fistulas, abscesses, or sinus tracts, presenting with similar symptoms.
- Necrotizing Soft Tissue Infection: Although less common, necrotizing soft tissue infections are life-threatening and can present with signs of infection such as purulent discharge. Early recognition is critical.
Rare Diagnoses
- Actinomycosis: A rare bacterial infection that can cause chronic abscesses, fistulas, and sinus tracts, especially in the pelvic region. It's more common in patients with a history of abdominal surgery or instrumentation.
- Tuberculous Fistula: Although rare in many parts of the world, tuberculosis can cause fistulas and sinus tracts, particularly in immunocompromised patients or those from endemic areas.
- Crohn's Disease: If not previously diagnosed, Crohn's disease could present with perianal disease, including fistulas and abscesses, leading to hemopurulent discharge. However, the patient's age and surgical history make this less likely as a new diagnosis.