Diagnostic efficiency of toluidine blue with Lugol's iodine in oral premalignant and malignant lesions.

Background and Objectives: In vivo stains are prompt resources, which have emerged, in the recent years, to aid as clinical diagnostic tools in detecting early premalignant and malignant lesions. The aim of the study was to determine the diagnostic efficiency of toluidine blue with Lugol's iodine in oral premalignancies and malignancies and to evaluate the reliability of in vivo staining with toluidine blue and Lugol's iodine in the lesions at risk of malignancy. Materials and Methods: The study group comprised 30 subjects with clinically suspicious premalignant lesions and 30 subjects with clinically suspicious malignant lesions. All the lesions were stained consecutively with toluidine blue and Lugol's iodine and the dye retention were recorded with photographs. Depending on the retention of the dyes, the biopsy site was determined. The biopsy specimens were sent for histological confirmation and results were statistically analyzed. Results: The overall diagnostic accuracy of Lugol's iodine when used consecutively with toluidine blue stain in distinguishing premalignant lesions and malignant lesions was 90%. As the degree of differentiation of malignant lesions progressed toward more severity, they failed to show the retention of Lugol's iodine and the result was highly significant statistically, with a P value < 0.001. Interpretation and Conclusion: Lugol's iodine when used with toluidine blue helped in delineating the inflammatory lesions and was the mean source in determining clinically the degrees of differentiation of malignant lesions as the poorly differentiated malignant lesions without glycogen content failed to show Lugol's iodine retention. Toluidine blue with Lugol's iodine can be used as a pretherapeutic assessment of the biologic aggressiveness of the disease.

High mast cell density associated with granulomatous formation in tuberculous lymphadenitis.

Mast cells are one of the main inflammatory cells involved in the pathogenesis of tuberculosis. Previous reports revealed that mast cells participated in both acute and chronic states of infection with Mycobacterium tuberculosis through direct contact or indirect enhancement by releasing mediators. The authors evaluated mast cell density on tissue sections of tuberculous lymphadenitis stained with 0.1% toluidine blue from 45 cases, all of which were retrieved from the surgical pathology files of King Chulalongkorn Memorial Hospital from 1999 to 2006. A number of mast cells were correlated semiquantitatively with granulomas which were formed by aggregation of epithelioid histiocytes, multinucleated giant cells, and caseous necrosis. We found that mast cell density was significantly increased in lymph nodes with greater granuloma involvement (p = 0.030) and multinucleated giant cell formation (p = 0.010). These findings indicate a significant correlation between mast cell density and the granulomatous formation responsible for M. tuberculosis.

Evaluation of mast cells in oral lichen planus and oral lichenoid reaction.

Recent attention has been directed towards the role of mast cells in the pathogenesis of oral lichen planus. Mast cells are responsible for trafficking of inflammatory cells into the connective tissue that in turn helps in progression and maintenance of the chronicity of oral lichen planus. In the present study we have evaluated the mast cell count and its cell types using toluidine blue stain, in oral lichen planus and compared it with oral lichenoid reactions. We have observed an increase in mast cell count in both these conditions in comparison to normal mucosa. Also, a significant difference in the types of mast cells in oral lichen planus and oral lichenoid reactions has been noted, possibly suggesting that the role of mast cell is different in these conditions.

The application of toluidine blue staining in non-gynecologic cytology.

The diagnostic accuracy of the toluidine blue stain approximates that of the Papanicolaou stain in non-gynecologic cytology. In this study a sensitivity of 95.3 and 96.9 per cent was achieved by used of the toluidine blue and Papanicolaou stains respectively. The specificity for both stains was identical at 96.3 per cent. Given the high degree of accuracy achieved with the toluidine blue stain in this study, and given its numerous advantages over the Papanicolaou stain, it is suggested that consideration be given to using the toluidine blue stain routinely in non-gynecologic cytology to differentiate malignancy from benignancy.