Sains Malaysiana 55(7)(2026): 1187-1197

http://doi.org/10.17576/jsm-2026-5507-07

Evaluation of Mast Cells in Oral Lichen Planus and Oral Lichenoid Reactions
(Penilaian Sel Mast dalam Lichen Planus Oral dan Tindak Balas Lichenoid Oral)

YET CHING GOH¹, ADRIANA ZULKARNAIN², NURUL NADIAH MOHD SHUKOR², ANAND RAMANATHAN^1,3, ALIAS ABD AZIZ⁴ & ZURAIZA MOHAMAD ZAINI^1,3,*

¹Department of Oral and Maxillofacial Clinical Sciences, Faculty of Dentistry, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
²Faculty of Dentistry, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
³Oral Cancer Research and Coordinating Centre, Faculty of Dentistry, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
⁴Department of Oral and Craniofacial Sciences, Faculty of Dentistry, Universiti Malaya, 50603 Kuala Lumpur, Malaysia

Diserahkan: 12 September 2025/Diterima: 8 Julai 2026

ABSTRACT

Oral lichen planus (OLP) and oral lichenoid reactions (OLR) including oral lichenoid contact lesion (OLCL) and oral lichenoid drug reaction (OLDR), are clinically and histopathologically similar conditions. Mast cells play a major role in immune responses and have been implicated in the pathogenesis of OLP. This study investigated mast cell counts in OLP, OLCL and OLDR using toluidine blue staining and its association with demographic, clinical and direct immunofluorescence findings. 60 samples (30 OLP, 18 OLDR, 12 OLCL) cases were examined for mast cells using toluidine blue staining. The mean mast cell counts were obtained from five subepithelial fields at 100x magnification and analyzed using Chi square and Kruskal-Wallis tests. OLDR showed significantly elevated mean mast cell counts (p=0.015), followed by OLCL and OLP. Significant associations were found between mean mast cell counts and presence of clinical symptoms in OLP (p=0.013) and number of involved sites in OLCL (p=0.045). Buccal mucosa was the most common affected site, and reticular form was the most frequently encountered clinical presentation in all lesion types. This study demonstrated significant differences in mast cell counts among OLP, OLCL, and OLDR, with the highest mast cell density observed in OLDR, supporting a contributory role of mast cells in the pathogenesis of oral lichenoid reactions. The observed associations with clinical features further suggest that mast cells may influence disease activity and clinical expression. Toluidine blue staining is a practical and reproducible adjunctive method for mast cell assessment and may aid in distinguishing clinically and histologically overlapping OLP and OLR lesions in routine diagnostic practice.

Keywords: mast cell; oral lichen planus; oral lichenoid contact lesion; oral lichenoid drug reaction

ABSTRAK

Liken planus oral (OLP) dan tindak balas likenoid oral (OLR) termasuk lesi sentuhan likenoid oral (OLCL) dan tindak balas ubat likenoid oral (OLDR) merupakan keadaan yang mempunyai persamaan dari segi ciri klinikal dan histopatologi. Sel mast memainkan peranan penting dalam tindak balas imun dan telah dikaitkan dengan patogenesis OLP. Kajian ini menilai bilangan sel mast dalam OLP, OLCL dan OLDR menggunakan pewarnaan toluidine biru serta hubungannya dengan maklumat demografik, ciri klinikal dan penemuan imunofluoresens langsung. Sebanyak 60 sampel (30 OLP, 18 OLDR, 12 OLCL) telah diperiksa untuk bilangan sel mast menggunakan pewarnaan toluidine biru. Purata bilangan sel mast diperoleh daripada lima medan subepitelium pada pembesaran 100x dan dianalisis menggunakan ujian Chi-square dan Kruskal-Wallis. OLDR menunjukkan purata bilangan sel mast yang meningkat secara signifikan (p=0.015), diikuti oleh OLCL dan OLP. Terdapat hubungan signifikan antara purata bilangan sel mast dan kehadiran simptom klinikal dalam OLP (p=0.013) dan bilangan tempat yang terlibat dalam OLCL (p=0.045). Mukosa bukal merupakan tempat paling kerap terlibat, manakala bentuk retikular merupakan persembahan klinikal yang paling biasa ditemui dalam semua jenis lesi. Kajian ini menunjukkan perbezaan yang signifikan dalam bilangan sel mast antara OLP, OLCL dan OLDR dengan ketumpatan sel mast tertinggi diperhatikan dalam OLDR, menyokong peranan sel mast dalam patogenesis tindak balas likenoid oral. Hubungan signifikan antara bilangan sel mast dan ciri klinikal terpilih turut menekankan kaitannya dengan aktiviti penyakit dan manifestasi klinikal. Pewarnaan toluidin biru terbukti sebagai kaedah tambahan yang praktikal dan boleh diulang untuk penilaian sel mast, serta berpotensi membantu dalam membezakan lesi OLP dan OLR yang bertindih dari segi klinikal dan histologi dalam amalan diagnostik rutin.

Kata kunci: Lesi sentuhan likenoid oral; liken planus oral; sel mast; tindak balas ubat likenoid oral

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*Pengarang untuk surat-menyurat; email: zuraiza@um.edu.my