What is the diagnosis for a 39-year-old female patient with a history of pulmonary tuberculosis (TB), presenting with bipedal edema, abdominal pain, increasing abdominal girth, dyspnea, hypotension, impaired renal function, and elevated liver enzymes?

Diagnosis: Tuberculous Peritonitis with Multisystem Involvement

This patient's presentation of bipedal edema, abdominal pain, increasing abdominal girth (ascites), dyspnea, hypotension, impaired renal function, and elevated liver enzymes in the context of prior pulmonary tuberculosis is most consistent with tuberculous peritonitis, likely complicated by renal involvement and hepatic dysfunction.

Clinical Reasoning

Primary Diagnosis: Abdominal Tuberculosis (Peritoneal)

The constellation of findings strongly suggests tuberculous peritonitis:

• Ascites with abdominal pain and increasing girth are present in 30-67% of abdominal TB cases and represent classic manifestations 1
• Fever and abdominal pain occur in 70-88% and 65-88% of abdominal TB cases respectively 1
• History of pulmonary TB is a critical risk factor, though up to 85% of abdominal TB patients have no active pulmonary involvement 1
• The systemic presentation with dyspnea and hypotension suggests disseminated or severe disease 2

Concurrent Complications

Renal Involvement (Genitourinary TB):

• Impaired renal function in a patient with TB history raises concern for genitourinary tuberculosis 2
• Renal TB can present insidiously and may lead to progressive renal insufficiency if diagnosis is delayed 3
• A positive urine culture for M. tuberculosis occurs commonly in disseminated disease and may reflect either true genitourinary involvement or disseminated TB 2

Hepatic Dysfunction:

• Elevated liver enzymes may represent either tuberculous hepatitis (part of disseminated disease) or drug-induced hepatotoxicity if the patient is already on anti-TB therapy 2, 4
• Abdominal TB can directly involve the liver, though this is less common than peritoneal involvement 1

Hemodynamic Instability:

• Hypotension suggests either sepsis from disseminated TB, adrenal insufficiency (from disseminated disease), or cardiac involvement (tuberculous pericarditis should be considered) 2
• Bipedal edema combined with ascites and hypotension raises concern for constrictive physiology if pericardial involvement is present 2

Diagnostic Approach

Immediate Evaluation Required

Ascitic Fluid Analysis:

• Perform diagnostic paracentesis with fluid sent for cell count, protein, glucose, adenosine deaminase (ADA), AFB smear, and mycobacterial culture 1
• Histopathological examination showing granulomas, caseous necrosis, or histiocytic ulcers has 69-97% sensitivity for extrapulmonary TB 1

Imaging:

• CT scan of abdomen is the imaging modality of choice for detecting and evaluating abdominal tuberculosis 1
• Look for ascites (free or loculated), peritoneal thickening, lymphadenopathy, and involvement of the ileocecal region (affected in 50-90% of GI TB cases) 1

Renal Assessment:

• Urine culture for M. tuberculosis to confirm genitourinary involvement 2
• Renal imaging (ultrasound or CT) to assess for hydronephrosis, ureteral obstruction, or structural abnormalities 2, 3
• Check for sterile pyuria (acid urine with leukocyturia) which is characteristic of renal TB 3

Cardiac Evaluation:

• Echocardiography to exclude tuberculous pericarditis, especially given hypotension and edema 2
• Pericardial involvement warrants adjunctive corticosteroid therapy 2

Hepatic Function:

• Determine if liver dysfunction is from TB involvement or drug toxicity 2
• If AST/ALT exceeds 5 times normal or bilirubin is elevated, hepatotoxic anti-TB drugs should be stopped 2

Critical Pitfalls to Avoid

Do not dismiss the diagnosis because of absent pulmonary symptoms - 85% of abdominal TB patients have no pulmonary involvement 1

Do not delay treatment awaiting culture confirmation - microbiological confirmation has low sensitivity due to paucibacillary nature of extrapulmonary TB 1. In endemic areas or high-risk patients, a therapeutic trial may be warranted with close monitoring 1

Do not overlook disseminated disease - the combination of peritoneal, renal, and hepatic involvement with hemodynamic instability suggests possible miliary or disseminated TB requiring extended treatment duration 2

Monitor for ureteral obstruction - renal TB can cause progressive obstruction leading to end-stage renal disease if not promptly addressed 2, 3. Stenting or nephrostomy may be required 2

Treatment Implications

Once diagnosis is confirmed, standard 6-month anti-TB therapy (isoniazid, rifampin, pyrazinamide, ethambutol for 2 months, then isoniazid and rifampin for 4 months) is recommended for both peritoneal and genitourinary TB 2, 1

However, treatment duration should be extended beyond 6 months if the patient remains culture-positive, has resistant organisms, or demonstrates slow response 1

Adjunctive corticosteroids are NOT routinely recommended for tuberculous peritonitis, as data are insufficient 2. However, if tuberculous pericarditis is confirmed, dexamethasone should be added 2

Dose adjustments are mandatory given renal impairment - ethambutol and streptomycin require dose reduction or avoidance in renal failure 2

Surgical intervention may be needed for complications such as intestinal obstruction, perforation, or diagnostic uncertainty requiring tissue diagnosis 1