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Oral Leukoplakia and Toluidine Blue Staining

Pelin Güneri*
Department of Oral Diagnosis and Radiology, Ege University School of Dentistry, Turkey


*Corresponding author: Pelin Güneri, Department of Oral Diagnosis and Radiology, Ege University School of Dentistry, Bornova 35100, İzmir, Turkey


Published: 15 Feb, 2017
Cite this article as: Güneri P. Oral Leukoplakia and Toluidine Blue Staining. Clin Surg. 2017; 2: 1315.

Clinical Image

A predominantly white oral mucosal lesion which cannot be related to any other causes and cannot be wiped off of oral mucosa is defined as oral leukoplakia (OL) [1-3]. This lesion is observed in 0.2% to 4.9% of the world population [3-5], and long-standing OLs are considered as antecedents of oral cancer lesions [4,6] with malignant transformation rate reaching up to 34% in some populations [3] within a follow-up period of 1 to 30 years [3,4]. A specific prevention method of this malignant transformation is not known yet, therefore successive and close follow up every OL lesion is recommended [7-9].
In order to assess the malignancy potential of OLs, various adjuncts have been utilized and toluidine blue (TBlue) staining is one of these methods [10-14]. This cationic metachromatic dye that selectively binds to free anionic groups of large molecules [11] and stains deoxyribonucleic and/or may be retained in intracellular spaces of dysplastic epithelium and clinically appear as royal blue areas in vivo [13,14]. Even though it is recommended that only dark royal blue staining in color should be regarded positive [15-18], others considered any uptake of blue dye positive, or classified pale staining either as positive or negative, or assigned to another category [14,19]. Healthy oral mucosa does not stain; but the dye may be noticed in retentive structures such as the fissures of the teeth and the papillae of the tongue. Additionally, other parts of oral cavity may stain very weakly with the tint of the saliva and appear as diffuse, filmy, and amorphous. Swabbing the area with acetic acid would remove the stain, and this may serve as an aid to differentiate these areas from actual suspicious sites [20]. Although nonmalignant areas of inflammation may also stain because inflammatory and ulcerative lesions tend to retain the dye due to greater cell activity and mechanical retention, false-positive results may be reduced by restraining fourteen days later after elimination of presumed etiological factors, at which time inflammatory changes usually resolve [16-20]. Retention of the stain is difficult in OL lesions because of increased thickness of the upper layer of oral mucosal epithelium (Figure 1 and 2). Thus, lower penetration of the toluidine blue dye through the white patches due to the hyperkeratotic nature of OL results with low sensitivity of this adjunct method. Therefore, the suitability of toluidine blue vital staining in primary care centers where a high proportion of white patches encountered are benign disorders appears debatable. With this argument, provided that weak penetration of the dye in hyperkeratotic lesions disguise the efficacy of toluidine blue in revealing the dysplastic oral mucosal tissues, the wide range of sensitivity and specificity values of toluidine blue staining in OLs may need to be reconsidered.


Figure 1

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Figure 1
A white patch at the anterior part of the floor of the mouth before and after toluidine blue staining. Histological diagnosis was parakeratotic hyperkeratosis.

Figure 2

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Figure 2
White patch on left buccal mucosa, near to the commisure before and after toluidine blue staining. Histological diagnosis revealed hyperkeratosis with mild dysplasia.

References

  1. van der Waal I. Oral potentially malignant disorders: is malignant transformation predictable and preventable? Med Oral Patol Oral Cir Bucal. 2014; 19: e386-390.
  2. van der Waal I, Schepman KP, van der Meij EH, Smeele LE. Oral leukoplakia: a clinicopathological review. Oral Oncol. 1997; 33: 291-301.
  3. Warna kulasuriya S, Ariyawardana A. Malignant transformation of oral leukoplakia: a systematic review of observational studies. J Oral Pathol Med. 2016; 45: 155-166.
  4. Lee JJ, Hung HC, Cheng SJ, Chen YJ, Chiang CP, Liu BY, et al. Carcinoma and dysplasia in oral leukoplakias in Taiwan: prevalence and risk factors. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006; 101: 472-480.
  5. Martorell-Calatayud A, Botella-Estrada R, Bagán-Sebastián JV, Sanmartín-Jiménez O, Guillén-Barona C. [Oral leukoplakia: clinical, histopathologic, and molecular features and therapeutic approach]. Actas Dermosifiliogr. 2009; 100: 669-684.
  6. Foy JP, Bertolus C, William WN Jr, Saintigny P. Oral premalignancy: the roles of early detection and chemoprevention. Otolaryngol Clin North Am. 2013; 46: 579-597.
  7. van der Waal I. Potentially malignant disorders of the oral and oropharyngeal mucosa; terminology, classification and present concepts of management. Oral Oncol. 2009; 45: 317-323.
  8. Ho MW, Field EA, Field JK, Risk JM, Rajlawat BP, Rogers SN, et al. Outcomes of oral squamous cell carcinoma arising from oral epithelial dysplasia: rationale for monitoring premalignant oral lesions in a multidisciplinary clinic. Br J Oral Maxillofac Surg. 2013; 51: 594-599.
  9. Mogedas-Vegara A, Hueto-Madrid JA, Chimenos-Küstner E, Bescós-Atín C. The treatment of oral leukoplakia with the CO2 laser: A retrospective study of 65 patients. J Craniomaxillofac Surg. 2015; 43: 677-681.
  10. Omar E. Current concepts and future of noninvasive procedures for diagnosing oral squamous cell carcinoma-a systematic review. Head Face Med. 2015; 11: 6.
  11. Gray MGL, Burls A, Elley K. The clinical effectiveness of toluidine blue dye as an adjunct to oral cancer screening in general dental practice. A West Midlands Development and Evaluation Service Report. 2000.
  12. Epstein JB, Silverman S Jr, Epstein JD, Lonky SA, Bride MA. Analysis of oral lesion biopsies identified and evaluated by visual examination, chemiluminescence and toluidine blue. Oral Oncol. 2008; 44: 538-544.
  13. Missmann M, Jank S, Laimer K, Gassner R. A reason for the use of toluidine blue staining in the presurgical management of patients with oral squamous cell carcinomas. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006; 102: 741-743.
  14. Patton LL, Epstein JB, Kerr AR. Adjunctive techniques for oral cancer examination and lesion diagnosis: a systematic review of the literature. J Am Dent Assoc. 2008; 139: 896-905.
  15. Gandolfo S, Pentenero M, Broccoletti R, Pagano M, Carrozzo M, Scully C. Toluidine blue uptake in potentially malignant oral lesions in vivo: Clinical and histological assessment. Oral Oncol. 2006; 42: 89-95.
  16. Güneri P, Epstein JB. The need to reassess studies on detection of potentially premalignant and malignant oral lesions. Oral Oncol. 2010; 46: e2-3.
  17. Güneri P, Epstein JB, Ergün S, Boyacioğlu H. Toluidine blue color perception in identification of oral mucosal lesions. Clin Oral Investig. 2011; 15: 337-345.
  18. Güneri P, Epstein JB, Kaya A, Veral A, Kazandı A, Boyacioglu H. The utility of toluidine blue staining and brush cytology as adjuncts in clinical examination of suspicious oral mucosal lesions. Int J Oral Maxillofac Surg. 2011; 40: 155-161.
  19. Ujaoney S, Motwani MB, Degwekar S, Wadhwan V, Zade P, Chaudhary M, et al. Evaluation of chemiluminescence, toluidine blue and histopathology for detection of high risk oral precancerous lesions: A cross-sectional study. BMC ClinPathol. 2012; 12: 6.
  20. Mashberg A, Samit A. Early diagnosis of asymptomatic oral and oropharyngeal squamous cancers. CA Cancer J Clin. 1995; 45: 328-351.