What is the diagnosis and management for a patient with progressive abdominal enlargement over 6 months, accompanied by fever, weight loss, productive cough, and grade 1 bipedal edema?

Progressive Abdominal Enlargement Over 6 Months with Fever, Weight Loss, Productive Cough, and Edema

This constellation of symptoms—progressive abdominal enlargement over 6 months combined with fever, weight loss, productive cough, and edema—demands immediate evaluation for tuberculosis (TB), particularly abdominal TB with pulmonary involvement, as this represents a potentially life-threatening but treatable condition. 1, 2

Immediate Diagnostic Priorities

Tuberculosis Must Be Excluded First

The combination of productive cough, fever, weight loss, and a 6-month progressive course is classic for TB and requires urgent evaluation 1, 2:

• Obtain chest X-ray immediately to evaluate for pulmonary TB, as patients with cough, fever, night sweats, and weight loss who are at risk for TB should have chest imaging when resources allow 1
• Collect three sputum specimens on separate days for acid-fast bacilli (AFB) smear, culture, and drug susceptibility testing 1, 2
• Request Xpert MTB/RIF testing (if available) to replace sputum microscopy for initial diagnostic testing, as this provides rapid molecular diagnosis 1, 2
• Perform Mantoux tuberculin skin test as part of the initial TB evaluation 1

The progressive 6-month timeline distinguishes this from acute processes and strongly suggests chronic infection or malignancy 1. TB commonly presents with cough lasting >2 weeks, and the WHO recommends investigation for TB when cough persists beyond this duration in high-prevalence settings 1.

Ascites vs. Solid Mass Differentiation

The slowly enlarging abdomen over 6 months is more consistent with ascites than obesity, as ascites typically presents over weeks while obesity develops over months to years 1:

• Perform abdominal paracentesis with ascitic fluid analysis if shifting dullness is present on physical examination, as this is the most rapid and cost-effective method of diagnosing the cause of ascites 1
• Obtain abdominal ultrasound to confirm fluid presence and distinguish ascites from solid masses, cysts, or pseudocysts 1
• Check for shifting dullness on percussion, which has 83% sensitivity for detecting ascites (requires approximately 1500 mL of fluid) 1

Critical Laboratory and Imaging Studies

• Complete blood count to assess for anemia and lymphocytosis 3
• Liver function tests and serum albumin to evaluate for cirrhosis-related ascites 1
• Contrast-enhanced CT chest, abdomen, and pelvis to evaluate pulmonary lesions, abdominal masses, lymphadenopathy, and stage potential malignancy 3
• HIV antibody testing with counseling, as HIV infection increases risk of TB and alters the differential diagnosis 1

Key Diagnostic Considerations

Tuberculosis (Highest Priority)

Pulmonary TB with abdominal involvement (peritoneal TB or abdominal lymphadenopathy) is the most critical diagnosis to exclude given the mortality risk and transmissibility 1, 2:

• Productive cough with constitutional symptoms (fever, weight loss) is the hallmark presentation of pulmonary TB 1, 2
• Abdominal TB can cause ascites and progressive abdominal enlargement 1
• The 6-month progressive course is consistent with chronic TB infection 4
• Bipedal edema may result from hypoalbuminemia secondary to chronic infection 1

If TB is confirmed or strongly suspected, initiate four-drug antimycobacterial therapy immediately: isoniazid, rifampin, pyrazinamide, and ethambutol for 2 months (intensive phase), followed by isoniazid and rifampin for at least 4 additional months 1, 2. Respiratory isolation is mandatory until three consecutive negative sputum smears or 3 weeks of effective therapy with clinical improvement 2.

Peritoneal Carcinomatosis

Malignancy must be considered given the progressive course and constitutional symptoms 1, 3:

• Peritoneal carcinomatosis does not respond to diuretic therapy and requires different management than cirrhotic ascites 1
• In young women, ovarian malignancy (particularly germ cell tumors) can present with abdominal enlargement and constitutional symptoms 3
• Obtain tumor markers: AFP, hCG (for germ cell tumors), and CA-125 (for epithelial ovarian neoplasms) 3

Cirrhosis with Ascites

Ascites due to cirrhosis is a common cause of progressive abdominal enlargement 1:

• Question about risk factors for liver disease, lifetime body weight (nonalcoholic steatohepatitis), alcohol use, and viral hepatitis 1
• Ascitic fluid analysis with serum-ascites albumin gradient (SAAG) differentiates portal hypertensive ascites (SAAG ≥1.1 g/dL) from other causes 1
• Jugular venous distension suggests cardiac ascites rather than cirrhotic ascites 1

Other Infectious Causes

• Tuberculous peritonitis should be specifically evaluated if ascites is present, as TB can cause ascites without obvious pulmonary involvement 1
• Parasitic infections (particularly in endemic areas) can cause eosinophilia, cough, and abdominal symptoms 1
• Fungal infections (histoplasmosis, coccidioidomycosis) can present with chronic cough, weight loss, and fever 1

Critical Management Pitfalls

• Never delay TB evaluation in patients with productive cough >2 weeks plus constitutional symptoms, as delayed diagnosis increases mortality and transmission risk 1
• Do not assume obesity when abdominal enlargement develops over 6 months—this timeline suggests pathology requiring investigation 1
• Avoid empiric diuretic therapy before determining the cause of ascites, as peritoneal carcinomatosis and tuberculous peritonitis do not respond to diuretics 1
• Recognize that normal white blood cell count does not exclude serious infection, as TB and other chronic infections may not cause leukocytosis 1

Algorithmic Approach

1. Immediate TB evaluation (chest X-ray, three sputum specimens for AFB smear/culture/Xpert MTB/RIF, tuberculin skin test, HIV testing) 1, 2
2. Physical examination for ascites (shifting dullness, flank dullness) 1
3. If ascites present: paracentesis with fluid analysis (cell count, albumin, culture, cytology) 1
4. If no ascites or solid mass suspected: abdominal ultrasound followed by CT chest/abdomen/pelvis 1, 3
5. Laboratory studies: CBC, liver function tests, albumin, tumor markers (AFP, hCG, CA-125), HIV testing 1, 3
6. If TB confirmed: initiate four-drug therapy immediately and implement respiratory isolation 1, 2
7. If malignancy suspected: urgent oncology consultation and tissue diagnosis 3

The bipedal edema likely represents hypoalbuminemia from chronic disease, malnutrition, or liver dysfunction rather than a primary cardiac or renal process 1. However, measure brain natriuretic peptide if cardiac ascites is suspected (median pro-BNP 6100 pg/mL in heart failure vs. 166 pg/mL in cirrhosis) 1.