title: Evaluation and Comparison of the Biopathology of Collagen and Inflammation in the Extracellular Matrix of Oral Epithelial Dysplasias and Inflammatory Fibrous Hyperplasia Using Picrosirius Red Stain and Polarising Microscopy: A Preliminary Study.
abstract: BACKGROUND
  The role of tumour inflammation and the dysplastic epithelial-stromal interactions on the nature of collagen fibres in the extracellular matrix of dysplastic epithelium is not fully understood. The present study was aimed to evaluate and compare the inflammation and pathological stromal collagen (loosely packed thin disorganized collagen) present in mild, moderate and severe epithelial dysplasias with that of inflammatory fibrous hyperplasias. The basement membrane intactness of epithelial dysplasias was also evaluated to determine if dysplastic epithelial mesenchymal interaction has any role in the integrity of stromal collagen in epithelial dysplasia.
  
  
  METHODS
  Oral epithelial dysplasias, inflammatory fibrous hyperplasia and normal oral mucosal samples were used for the study. Packing, thickness and orientation of collagen fibres in mild, moderate and severe grades of oral epithelial dysplasias (n = 24), inflammatory fibrous hyperplasia (n = 8) and normal oral mucosal samples (n = 8) were analysed based on the polarisation of collagen fibres in picrosirius red polarising stain under polarising microscope.
  
  
  RESULTS
  All the grades of epithelial dysplasias showed greenish yellow birefringence confirming the presence of loosely arranged pathological collagen in the presence of moderate inflammation. All the cases of inflammatory fibrous hyperplasia showed red polarisation hue and moderate inflammation. A statistically significant difference was found in the packing and orientation of collagen when epithelial dysplasias and inflammatory fibrous hyperplasia were compared (P < 0.01). When the intactness of basement membrane integrity was compared in all the groups of epithelial dysplasia, a statistically significant result was obtained (P < 0.05).
  
  
  CONCLUSIONS
  Presence of significant amount of loosely packed thin disoriented collagen even in mild epithelial dysplasia suggests that tumourigenic factors are released to connective tissue stroma much earlier than expected. Hence we suggest considering the integrity of extracellular matrix collagen, intactness of basement membrane and inflammation associated with dysplasia along with the anaplasia of epithelial cells in the microscopic assessment of dysplastic epithelium.
authors.affiliation: Department of Oral Pathology and Microbiology, Mar Baselios Dental College and Hospital, Kothamangalam, Ernakulam, Kerala, India.
authors.forename: Soma Susan
authors.initials: SS
authors.lastname: Varghese
authors.affiliation: Department of Oral Pathology and Microbiology, Mar Baselios Dental College and Hospital, Kothamangalam, Ernakulam, Kerala, India.
authors.forename: Sreenivasan Bargavan
authors.initials: SB
authors.lastname: Sarojini
authors.affiliation: Department of Oral Medicine and Radiology, Mar Baselios Dental College and Hospital, Kothamangalam, Ernakulam, Kerala, India.
authors.forename: Giju Baby
authors.initials: GB
authors.lastname: George
authors.affiliation: Department of Oral and Maxillofacial Surgery, Mar Baselios Dental College and Hospital, Kothamangalam, Ernakulam, Kerala, India.
authors.forename: Sankar
authors.initials: S
authors.lastname: Vinod
authors.affiliation: Department of Oral Medicine and Radiology, Government Dental College, Kottayam, Kerala, India.
authors.forename: Philips
authors.initials: P
authors.lastname: Mathew
authors.affiliation: Department of Conservative Dentistry and Endodontics, Government Dental College, Thiruvananthapuram, Kerala, India.
authors.forename: Anulekh
authors.initials: A
authors.lastname: Babu
authors.affiliation: Department of Oral Pathology and Microbiology, Mar Baselios Dental College and Hospital, Kothamangalam, Ernakulam, Kerala, India.
authors.forename: Joseph
authors.initials: J
authors.lastname: Sebastian
keywords: Collagen; Dysplasia; Extracellular matrix; Oral mucosa