Toxoplasma Appendicitis: A Once-in-a-Lifetime Diagnosis!

Area of Science:

• Medical Parasitology
• Gastrointestinal Pathology
• Immunocompromised Host Infections

Background:

• Toxoplasmosis, caused by *Toxoplasma gondii*, is typically asymptomatic in immunocompetent individuals.
• However, it poses a significant risk of severe illness in immunocompromised patients.
• Appendicitis is a common surgical emergency, but parasitic infections are rarely considered in its differential diagnosis.

Observation:

• A 62-year-old male presented with symptoms suggestive of acute appendicitis.
• Histopathological examination revealed eosinophilic transmural infiltrate, reactive lymphoid follicles, and *Toxoplasma* tachyzoites in the appendiceal wall.
• Immunohistochemistry confirmed *Toxoplasma* appendicitis, despite negative serological results.

Findings:

• The patient was on long-term immunosuppressive therapy with methotrexate, a key factor in his presentation.
• Diagnosis was confirmed via histology and immunohistochemistry, highlighting the parasite's presence in the appendix.
• Negative serology in an immunocompromised host underscores the importance of histological confirmation.

Implications:

• This case emphasizes the need to consider *Toxoplasma* appendicitis in the differential diagnosis of appendicitis, particularly in immunosuppressed individuals.
• Prompt treatment with sulfamethoxazole-trimethoprim led to a positive outcome, with the patient remaining asymptomatic at 7-month follow-up.
• This highlights the importance of integrating clinical, histological, and immunological findings for accurate diagnosis and management of opportunistic infections in immunocompromised patients.