70 patients with suspicious oral lichen planus; atrophic and bullous erosive forms will be included. The blood samples will be drawn between 08:00 and 09:00 AM, after a fasting period of 12 hours, and analysis were performed within 2 hours of the sampling. The MPV and other hematologic parameters will be measured in a blood sample. A surgical biopsy will be performed for histopathological assessment.

70 patients with suspicious oral lichen planus; atrophic and bullous erosive forms will be included for conventional clinical examination under incandescent projected light. Using biopsy as a gold standard, all patients will be biopsied.

Blood Samples For all participants, the blood samples will be drawn between 08:00 and 09:00 AM, after a fasting period of 12 hours, and analysis were performed within 2 hours of the sampling. The MPV and other hematologic parameters will be measured in a blood sample that will be collected in tubes containing EDTA. Complete blood cell analysis will be performed in hematology laboratory, New Kasr Al-Aini Teaching Hospital, Faculty of Medicine, Cairo University. For reliable MPV measurement, the investigator will standardize the time delay between sampling and analysis to <2 hours for all patients.

Biopsy preparation A surgical biopsy will be performed for histopathological assessment. All clinically identified lesions underwent biopsies where specimens will be placed in 10% buffered formalin for fixation. Paraffin embedded material will be cut into 4 μm thick sections and will be stained with haematoxylin + eosin then submitted for histopathological evaluation by a senior oral pathologist blinded to the clinical findings.

Statistical analysis

The collected data will be entered through the SPSS version 18.0 software. Sensitivity, Specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV) and Accuracy were calculated for MPV. The results will be compared with histopathological results using Chi-Square test with p value set as < 0.05.

Inclusion Criteria:

• Inclusion criteria is suspected oral lichen planus, age 18-60

Exclusion Criteria:

• Foreseeable missing opportunity of follow-up examination, Pregnancy, heart-, pulmonary, liver- and kidney disease, chronic pain syndrome nursing, drug addiction, recent operations, and diseases like heart, metabolism, CNS, infectious, circulation, systemic, malignant and immune system affecting diseases as well as blood coagulation disorders and allergic reactions to pharmaceuticals and antibiotics

Patients suspected to have oral lichen planus