From the Guidelines
Splenic granulomas are most commonly caused by histoplasmosis, a fungal infection caused by Histoplasma capsulatum, as evidenced by the formation of granulomas with yeasts resembling H. capsulatum in extrapulmonary tissues, including the spleen 1.
Causes of Splenic Granuloma
Other infectious causes of splenic granuloma include:
- Tuberculosis infection, particularly from Mycobacterium tuberculosis
- Bacterial infections (brucellosis, syphilis, cat scratch disease from Bartonella henselae)
- Parasitic infections (schistosomiasis, visceral leishmaniasis)
- Fungal infections (cryptococcosis, candidiasis)
Diagnosis and Treatment
Diagnosis typically requires imaging studies like CT or ultrasound, followed by tissue sampling through biopsy or splenectomy for definitive identification of the causative organism.
- Treatment depends on the specific infectious agent identified, with histoplasmosis requiring antifungal medications like amphotericin B or itraconazole 1.
- Bacterial infections are treated with appropriate antibiotics based on sensitivity testing.
- Granulomas form as an immune response to contain infections, with macrophages, lymphocytes and other immune cells clustering around the pathogen to prevent its spread throughout the body.
Key Considerations
It is essential to note that the evidence from 1 is more relevant to the question of splenic granuloma than 1, which discusses splenic abscess, a different condition.
- The diagnosis and treatment of splenic granuloma should be guided by the most recent and highest-quality evidence available, which in this case is the 2007 update by the Infectious Diseases Society of America 1.
From the Research
Infections Causing Splenic Granuloma
- Mycobacterium avium complex (MAC) infection can cause splenic granulomas, even in immunocompetent individuals 2
- Tuberculosis (TB) is another infection that can cause splenic granulomas, often seen in disseminated or miliary form of the disease, particularly in patients with HIV infection 3, 4
- Melioidosis, caused by Burkholderia pseudomallei, can also present as chronic splenic granuloma, often misdiagnosed as tuberculosis due to lack of clinical suspicion and laboratory facilities 5
- Sarcoidosis, an autoimmune disease, can also involve the spleen and cause granulomatous inflammation, which can be difficult to differentiate from TB 6
Characteristics of Infections
- MAC infection can present as fever of unknown origin and multiple splenic granulomas, diagnosed through fine needle aspiration cytology and PCR 2
- TB can present with constitutional symptoms such as fever, anorexia, and weight loss, and ultrasonography can be useful for diagnosis 3
- Melioidosis can present as deep-seated abscess requiring intensive treatment with intravenous antibiotics 5
- Sarcoidosis can present with nonspecific constitutional symptoms and granulomatous inflammation in various organs, including the spleen 6