Describe the sites, pathology, clinical features, diagnosis and management of genital Tuberculosis.

A common cause of infertility in India, often silent.

Definition

Genital tuberculosis is tuberculous infection of the female genital tract, caused by *Mycobacterium tuberculosis*. It is almost always secondary to a focus elsewhere (lungs, lymph nodes, gut, urinary tract or bones), reaching the genital tract by haematogenous (mainly), lymphatic or direct spread. It is an important and rising cause of infertility in developing countries.

Genital TB - Spread & Sites

Sites of Involvement

• Fallopian tubes (≈ 90–100%) — the primary and almost constant site.
• Endometrium (≈ 50%) — by downward spread from the tubes.
• Ovaries (≈ 20–30%), cervix (≈ 5%), and rarely the vagina and vulva.

Pathology

Tuberculous tubercles with caseation develop in the tubes, which become thickened and may form a "tobacco-pouch" appearance with everted fimbriae, beading, and tubo-ovarian masses or a "frozen pelvis" from adhesions. Endometrial involvement causes destruction and intra-uterine synechiae (Asherman-like), and tubal scarring leads to infertility and a high risk of ectopic pregnancy.

Clinical Features

Infertility is the commonest presentation (often the only complaint). Others include menstrual disturbances (oligomenorrhoea, amenorrhoea or abnormal bleeding), chronic pelvic pain, vaginal discharge, and constitutional symptoms (low-grade fever, weight loss, evening rise of temperature); many women are asymptomatic and detected during an infertility work-up.

Diagnosis

• Endometrial biopsy/curettage in the pre-menstrual phase — for histology (tubercles), acid-fast bacilli, culture and PCR (the most useful test); menstrual-blood culture/PCR is an alternative.
• Hysterosalpingography — a rigid, beaded ("pipe-stem") tube, cornual block, calcification, and a distorted/contracted cavity with synechiae.
• Laparoscopy/hysteroscopy — tubercles, tubo-ovarian masses and adhesions, with biopsy.
• Supportive — Mantoux test, chest radiograph, ESR, and a search for an extragenital focus.

Management

• Anti-tubercular therapy (ATT) is the mainstay — the standard four-drug regimen (isoniazid, rifampicin, pyrazinamide, ethambutol) for an intensive phase, followed by a continuation phase, for a total of about 6 months.
• Surgery is reserved for a residual or persistent tubo-ovarian mass, or non-response to ATT.
• Infertility — tubal damage is usually irreversible, so in-vitro fertilisation is the realistic option (tubal surgery has poor results); a severely damaged endometrium carries a poor prognosis.

WHY Genital TB Is a Silent Destroyer of Fertility

The distinguishing feature of genital tuberculosis — and the reason it is so important in India — is why it destroys fertility while causing almost no symptoms. It is almost always secondary, spreading haematogenously from a primary focus in the lung (or from the abdomen), so the woman has usually had no overt tuberculosis and feels perfectly well. The organism seeds the fallopian tubes first (involved in over 90% of cases — they are the primary genital site), and then the endometrium (in about 50%). In the tube it produces a chronic granulomatous inflammation that silently obliterates the lumen, giving the characteristic beaded, rigid, 'lead-pipe' tube, with fimbrial destruction and the classic 'tobacco-pouch' appearance. In the endometrium it destroys the basal layer and produces intrauterine adhesions. The result is that the commonest — and often the only — presentation is infertility (in some series it accounts for a substantial proportion of tubal infertility in India), sometimes with menstrual disturbance ending in amenorrhoea (from endometrial destruction), and chronic pelvic pain. Understanding that the disease is silent, that the tube is destroyed before anything is noticed, explains why it must be actively suspected in any infertile Indian woman.

WHY Anti-tubercular Treatment Cures the Infection But Not the Infertility

A hard clinical truth worth understanding is why a woman with genital tuberculosis may be cured of her infection and still never conceive naturally. Anti-tubercular therapy (the standard multi-drug regimen) is highly effective at eradicating the organism — it reliably cures the infection. But it cannot rebuild what has already been destroyed: the ciliated tubal epithelium, the delicate fimbriae and the endometrial basal layer do not regenerate, and the fibrosis, tubal blockage and intrauterine adhesions remain. So the drugs stop the disease from progressing and make it safe to attempt pregnancy — but the damage is permanent. This has two important consequences. First, tubal reconstructive surgery is generally disappointing in genital TB (the tube is diseased along its length, not merely blocked at a point), so IVF — which bypasses the tubes altogether — is the treatment of choice for fertility; though even IVF may fail if the endometrium is severely damaged, in which case surrogacy may be the only option. Second, and most importantly, it explains why early diagnosis matters so much: the fertility that is saved is the fertility that has not yet been destroyed — which is the whole argument for suspecting the disease early.

• Genital TB is almost always secondary (haematogenous spread from a lung/abdominal focus); the fallopian tube is involved in >90%, the endometrium in ~50%.
• It is typically silent — the commonest presentation is infertility, with menstrual disturbance (oligomenorrhoea → amenorrhoea) and chronic pelvic pain.
• Diagnosis: endometrial biopsy/curettage in the premenstrual phase for AFB, culture and CBNAAT/PCR and histology (caseating granuloma); HSG shows beaded, rigid 'lead-pipe' tubes; laparoscopy shows tubercles and adhesions.
• Treatment: standard multi-drug anti-tubercular therapy — which cures the infection but cannot reverse the structural damage.
• Fertility: tubal surgery gives poor results; IVF is the treatment of choice (surrogacy if the endometrium is destroyed) — hence early diagnosis is everything.