A 30-year-old presents with infertility, menstrual irregularity, and constitutional symptoms. Laparoscopy shows fimbrial occlusion with beaded tubes. Endometrial biopsy demonstrates Langhans giant cells and caseation. The investigation with highest sensitivity for confirming genital tuberculosis in this case is:
- A Mantoux (tuberculin skin test) 15 mm induration
- B Morning urine culture on Lowenstein-Jensen medium
- C Serum adenosine deaminase (ADA) levels
- D Nucleic acid amplification test (NAAT/PCR) for Mycobacterium tuberculosis on endometrial biopsy ✓
Explanation
PCR/NAAT for M. tuberculosis DNA on endometrial biopsy is the most sensitive investigation for genital tuberculosis, detecting mycobacterial DNA even in paucibacillary disease where culture and smear are negative. Endometrial biopsy is the preferred tissue for testing. Culture on Lowenstein-Jensen medium is the gold standard for viable organisms but requires 4–8 weeks and has lower sensitivity in genital TB. Mantoux is supportive but non-specific. Histology (caseating granulomas with Langhans cells) is highly specific when positive but requires sufficient tissue. NAAT combines speed and sensitivity.
Reference: Shaw's Textbook of Gynaecology, 17th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.