In genital tuberculosis, the most reliable diagnostic test combining PCR, culture, and histology is the GeneXpert MTB/RIF (Xpert). The characteristic histological finding in fallopian tube tuberculosis that is nearly pathognomonic is:
- A Nodular thickening of the isthmic portion (salpingitis isthmica nodosa)
- B Diffuse lymphocytic infiltration of the tubal mucosa
- C Tuberculous granuloma within the tubal lumen with central caseous necrosis ✓
- D Pipe-stem calcification visible on hysterosalpingography
Explanation
The histological hallmark of fallopian tube tuberculosis is the presence of caseating (caseous necrosis-containing) granulomas within the tubal lumen—a finding essentially pathognomonic for tuberculosis, as other granulomatous infections rarely produce intraluminal caseation. The granulomas consist of epithelioid cells, Langhans giant cells, lymphocytes, and central caseous necrosis. Salpingitis isthmica nodosa is a non-specific finding associated with Chlamydia and infertility, not specific to TB. Pipe-stem calcification on HSG may suggest TB but is not diagnostic. The GeneXpert MTB/RIF assay on menstrual blood or endometrial curettings has a sensitivity of ~70–80% and is increasingly used in high-burden countries.
Reference: Shaw's Textbook of Gynaecology, 17th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.