A18.85 Tuberculosis of spleen

Name of the Condition

• Tuberculosis of spleen
• ICD Code: A18.85

Summary

Tuberculosis of the spleen is a form of extrapulmonary tuberculosis where Mycobacterium tuberculosis infects the spleen. This condition occurs when TB bacteria spread from a primary site, typically the lungs, to the spleen via the bloodstream or lymphatic system. It may present with splenomegaly, pain, or systemic symptoms, depending on the extent of infection and tissue involvement.

Causes

Tuberculosis of the spleen is caused by the dissemination of Mycobacterium tuberculosis from an existing infection, usually pulmonary tuberculosis. The bacteria can travel to the spleen during active disease or reactivation of latent TB. Direct inoculation is rare but possible in certain cases.

Risk Factors

• Immunocompromised states, such as HIV/AIDS or chronic steroid use.
• History of untreated or inadequately treated tuberculosis.
• Close contact with individuals who have active TB.
• Living in or traveling to regions with high TB prevalence.
• Underlying conditions like diabetes or malnutrition.

Symptoms

• Splenomegaly (enlarged spleen), which may cause abdominal discomfort or pain.
• Left upper quadrant tenderness.
• Systemic symptoms such as fever, night sweats, or weight loss.
• Fatigue or malaise.

Diagnosis

Diagnosis involves a combination of clinical evaluation, imaging (e.g., ultrasound or CT scan to assess spleen size and abnormalities), and laboratory tests. A definitive diagnosis often requires splenic tissue sampling (e.g., biopsy) to detect Mycobacterium tuberculosis via culture or molecular testing. Additional tests may include blood work to assess for systemic infection or organ dysfunction.

Treatment Options

Treatment follows standard antitubercular therapy, typically a multi-drug regimen (e.g., isoniazid, rifampin, pyrazinamide, and ethambutol) for 6–9 months. Duration and specific drugs may be adjusted based on drug resistance, patient tolerance, or disease severity. Close monitoring for treatment response and adverse effects is essential.

Prognosis and Follow-Up

With appropriate treatment, the prognosis is generally favorable, though outcomes depend on the extent of infection, underlying health, and timely intervention. Follow-up includes regular clinical assessments, imaging to monitor spleen size, and laboratory tests to evaluate treatment response. Long-term monitoring for recurrence or complications may be necessary.

Complications

• Rupture of the spleen (rare but serious).
• Abscess formation within the spleen.
• Disseminated tuberculosis if the infection spreads further.
• Chronic splenic dysfunction or fibrosis.

Lifestyle & Prevention

• Adhere to prescribed antitubercular therapy to prevent progression or recurrence.
• Maintain good overall health to support immune function.
• Avoid exposure to individuals with active TB in high-prevalence settings.
• Follow public health guidelines for TB prevention, including vaccination (BCG) where recommended.

When to Seek Professional Help

Seek medical attention if you experience persistent abdominal pain, unexplained fever, night sweats, or unexplained weight loss, especially if you have a history of TB exposure or immunocompromising conditions.

Tips for Medical Coders

Code A18.85 is specific to tuberculosis of the spleen and should be used when the spleen is the primary site of extrapulmonary TB infection. Documentation should clearly indicate the organ involved and confirm the diagnosis (e.g., via biopsy or imaging). Ensure the code aligns with clinical findings and avoid using this code for generalized or unspecified extrapulmonary TB.