Role of Chromo-hysteroscopy with Toluidine Blue in Diagnosing Endometrial Pathology after 40 years of Age

Endometrial Cancer is the sixth most common cancer in females worldwide. The lifetime risk of developing the disease is approximately 2.7%. Endometrial cancer often develops in the setting of endometrial hyperplasia that is now being established as a premalignant state. Clinical presentation of both endometrial hyperplasia and endometrial carcinoma is similar. They present as menorrhagia, poly-menorrhoea, inter-menstrual bleeding or postmenopausal bleeding. Almost 15% of outpatient cases and 25% of gynecologic surgery cases present with abnormal uterine bleeding (AUB).

Such abnormal uterine bleeding (AUB) in perimenopausal & menopausal women is routinely investigated with ultrasonography, hysteroscopy and endometrial biopsy. Hysteroscopy guided endometrial biopsy is considered gold standard since it allows direct visualization of the endometrial lesions and directed biopsy thereafter. Sometimes focal endometrial hyperplasia or early endometrial cancer may also be missed on hysteroscopy. Chromo-hysteroscopy is a new technique in which some staining agent is used during hysteroscopy to identify focal endometrial lesions. Chromo hysteroscopy identifies endometrium to be targeted for biopsy with the help of staining dyes like methylene blue, Lugols’s solution, Congo red and Indigo Caramine . The earliest use of Methylene blue or other vital stains or dyes in the endometrium dates back to 1980s when it was used to distinguish normal endometrial tissue from fibrotic one in Asherman’s syndrome . Ozturk et al., conducted a cross-sectional study in 50 patients to evaluate the usefulness of endometrial staining for locating the sampling areas during frozen section procedures of hysterectomy specimens . They suggested that chromo-hysteroscopy with toluidine blue could help in pre-operative evaluation for endometrial hyperplasia & endometrial carcinoma during hysteroscopy.

Toluidine blue is an acidophilic, vital dye of the thiazine group that stains cellular nuclei containing DNA and RNA. These characteristics make toluidine blue useful for identifying premalignant and malignant tissues that have increased DNA synthesis. Toluidine blue is also used to screen for early squamous esophageal cancers.