**Histopathology III** **Benign epithelial pathoses** **and potentially malignant** **disorders** A/Prof Omar Kujan # **Histopathology III: Benign Epithelial Pathoses and Potentially Malignant Disorders** **A/Prof Omar Kujan** **Contents** - **Glossary of terms used in histopathological diagnosis of premalignant lesions** To proceed through the text just click on the arrows, click on **🏠** to return to this page # **Contents** - **Glossary of terms used in histopathological diagnosis of premalignant lesions** To proceed through the text just click on the arrows, click on **🏠** to return to this page Pathological change in the overall structure of an epithelium can be described as:- a) acanthosis b) atrophy c) keratosis e) orthokeratosis f) parakeratosis # **Pathological Changes in Epithelium** Pathological change in the overall structure of an epithelium can be described as: - a) acanthosis - b) atrophy - c) keratosis - e) orthokeratosis - f) parakeratosis Photomicrograph showing acanthotic oral epithelium. The epithelium is thicker due to an increased number of ‘prickle’ cells causing the rete ridges to broaden and lengthen (arrows) Photomicrographs comparing normal oral epithelium with acanthotic epithelium Photomicrograph showing atrophic oral epithelium. The thickness of the epithelium is reduced and often the rete pegs are lost ## **Atrophy** Photomicrograph showing atrophic oral epithelium. The thickness of the epithelium is reduced and often the rete pegs are lost Photomicrographs comparing normal oral epithelium with atrophic epithelium Photomicrograph showing keratosis of an epithelium (arrowed) that is not normally keratinised Photomicrographs comparing normal oral epithelium with keratotic epithelium Photomicrograph showing orthokeratosis of an epithelium - the superficial cell layers are increased in thickness, the cells are flattened and have no nuclei, the layer stains bright pink. Note the granular layer in the superficial keratinocytes (arrowed), this is a feature of orthokeratosis ## **Orthokeratosis** Photomicrograph showing orthokeratosis of an epithelium - the superficial cell layers are increased in thickness, the cells are flattened and have no nuclei, the layer stains bright pink. Note the granular layer in the superficial keratinocytes (arrowed), this is a feature of orthokeratosis Photomicrograph showing parakeratosis of an epithelium - the superficial cell layers are increased in thickness, the cells are often flattened and contain pyknotic (dark condensed, arrowed) nuclei, the layer stains bright pink ## **Parakeratosis** Photomicrograph showing parakeratosis of an epithelium - the superficial cell layers are increased in thickness, the cells are often flattened and contain pyknotic (dark condensed, arrowed) nuclei, the layer stains bright pink **Oral epithelial dysplasia** # **Oral Epithelial Dysplasia** # Dysplasia Grading ## WHO 2022 Classification - Mild Dysplasia - Moderate Dysplasia - Severe Dysplasia ## **Dysplasia Grading** ### **WHO 2022 Classification** - **3-Tier System:** - Mild Dysplasia - Moderate Dysplasia - Severe Dysplasia *Dysplasia Grading* **WHO 2022 Classification** 1. Low grade oral epithelial dysplasia 2. High grade oral epithelial dysplasia - **2-Tier System:** 1. Low grade oral epithelial dysplasia 2. High grade oral epithelial dysplasia **Architecture Changes** 1- Irregular epithelial stratification 2- Loss of polarity of basal cells 3- Drop-shaped rete ridges 4- Increased number of mitotic figures 5- Abnormally superficial mitoses 6- Premature keratinisation in single cells 7- Keratin pearls within rete ridges 8- Loss of epithelial cohesion ## **Architectural Changes** 1. Irregular epithelial stratification 2. Loss of polarity of basal cells 3. Drop-shaped rete ridges 4. Increased number of mitotic figures 5. Abnormally superficial mitoses 6. Premature keratinisation in single cells 7. Keratin pearls within rete ridges 8. Loss of epithelial cohesion # Cytology Changes 1. Abnormal variation in nuclear size 2. Abnormal variation in nuclear shape 3. Abnormal variation in cell size 4. Abnormal variation in cell shape 5. Increased Nuclear-cytoplasmic ratio 6. Increased nuclear size 7. Atypical mitoses 8. Increase number and size of nucleoli 9. Hyperchromatism ## **Cytological Changes** 1. Abnormal variation in nuclear size 2. Abnormal variation in nuclear shape 3. Abnormal variation in cell size 4. Abnormal variation in cell shape 5. Increased Nuclear-cytoplasmic ratio 6. Increased nuclear size 7. Atypical mitoses 8. Increase number and size of nucleoli 9. Hyperchromatism **Oral Oncology (2006) 42, 987–993** available at www.sciencedirect.com **ELSEVIER** **ScienceDirect** journal homepage: http://intl.elsevierhealth.com/journals/oron/ **ORAL ONCOLOGY** **Evaluation of a new binary system of grading oral epithelial dysplasia for prediction of malignant transformation** **Omar Kujan**a, **Richard J. Oliver**a, **Ammar Khattab**b, **Stephen A. Roberts**c, **Nalin Thakker**a, **Philip Sloan**a,* aSchool of Dentistry, The University of Manchester, Manchester M15 6FH, United Kingdom bTrafford General Hospital Trust, Manchester, United Kingdom cBiostatistics Group, The University of Manchester, Manchester M15 6FH, United Kingdom ## **Reference Study: Evaluation of a New Binary Grading System** **Oral Oncology (2006) 42, 987–993** journal homepage: http://intl.elsevierhealth.com/journals/oron/ **Evaluation of a new binary system of grading oral epithelial dysplasia for prediction of malignant transformation** **Omar Kujan**a, **Richard J. Oliver**a, **Ammar Khattab**b, **Stephen A. Roberts**c, **Nalin Thakker**a, **Philip Sloan**a,* - aSchool of Dentistry, The University of Manchester, Manchester M15 6FH, United Kingdom - bTrafford General Hospital Trust, Manchester, United Kingdom - cBiostatistics Group, The University of Manchester, Manchester M15 6FH, United Kingdom ```markdown <4 architecture changes + <5 cytological changes **Low-grade lesion** ≥4 architecture changes + ≥5 cytological changes **High-grade lesion** ``` ### **Binary System Criteria** - **Low-grade lesion** - <4 architecture changes - + - <5 cytological changes - **High-grade lesion** - ≥4 architecture changes - + - ≥5 cytological changes **Orthokeratinisation** **Mitotic activity** **Loss polarity of basal cells** ## **Key Histological Features of Dysplasia** - Orthokeratinisation - Mitotic activity - Loss polarity of basal cells Histological section showing stratified squamous epithelium with three distinct layers: superficial, intermediate, and basal. **Individual cell keratinisation** **Drop shaped rete ridges** **Mitotic activity** - Individual cell keratinisation - Drop shaped rete ridges - Mitotic activity Microscopic image of skin tissue showing epidermal layers with distinct cell structures and a demarcation line separating upper and lower regions. Microscopic image of stratified squamous epithelium, showing layers of cells with varying morphology and staining intensity. Histological section showing stratified squamous epithelium with underlying connective tissue. Histological image of epithelial tissue showing layers of cells and dermal structures Histological section of skin showing epidermis and dermis with labeled sebaceous glands Four histological images showing progression from Normal to Moderate dysplasia, Severe dysplasia, and Carcinoma in-situ. The severity of the dysplasia may vary considerably over the lesion as may also the histological features. The following photomicrographs illustrate a large dysplastic lesion of the palate and the histological variation that is encountered between different parts of the lesion **Blocks taken for histopathology** Oral cavity image showing a marked lesion on the palate with labeled biopsy sites. ## **Histological Variation in Dysplastic Lesions** The severity of the dysplasia may vary considerably over the lesion as may also the histological features. The following photomicrographs illustrate a large dysplastic lesion of the palate and the histological variation that is encountered between different parts of the lesion. **Blocks taken for histopathology** [[W3 IntrotoHistoapthology.pdf#page=1|W3 IntrotoHistoapthology, p.1]] [[W3 IntrotoHistoapthology.pdf#page=2|W3 IntrotoHistoapthology, p.2]] [[W3 IntrotoHistoapthology.pdf#page=3|W3 IntrotoHistoapthology, p.3]] [[W3 IntrotoHistoapthology.pdf#page=4|W3 IntrotoHistoapthology, p.4]] [[W3 IntrotoHistoapthology.pdf#page=5|W3 IntrotoHistoapthology, p.5]] [[W3 IntrotoHistoapthology.pdf#page=6|W3 IntrotoHistoapthology, p.6]] [[W3 IntrotoHistoapthology.pdf#page=7|W3 IntrotoHistoapthology, p.7]] [[W3 IntrotoHistoapthology.pdf#page=8|W3 IntrotoHistoapthology, p.8]] [[W3 IntrotoHistoapthology.pdf#page=9|W3 IntrotoHistoapthology, p.9]] [[W3 IntrotoHistoapthology.pdf#page=10|W3 IntrotoHistoapthology, p.10]] [[W3 IntrotoHistoapthology.pdf#page=11|W3 IntrotoHistoapthology, p.11]] [[W3 IntrotoHistoapthology.pdf#page=12|W3 IntrotoHistoapthology, p.12]] [[W3 IntrotoHistoapthology.pdf#page=13|W3 IntrotoHistoapthology, p.13]] [[W3 IntrotoHistoapthology.pdf#page=14|W3 IntrotoHistoapthology, p.14]] [[W3 IntrotoHistoapthology.pdf#page=15|W3 IntrotoHistoapthology, p.15]] [[W3 IntrotoHistoapthology.pdf#page=16|W3 IntrotoHistoapthology, p.16]] [[W3 IntrotoHistoapthology.pdf#page=17|W3 IntrotoHistoapthology, p.17]] [[W3 IntrotoHistoapthology.pdf#page=18|W3 IntrotoHistoapthology, p.18]] [[W3 IntrotoHistoapthology.pdf#page=19|W3 IntrotoHistoapthology, p.19]] [[W3 IntrotoHistoapthology.pdf#page=20|W3 IntrotoHistoapthology, p.20]] [[W3 IntrotoHistoapthology.pdf#page=21|W3 IntrotoHistoapthology, p.21]] [[W3 IntrotoHistoapthology.pdf#page=22|W3 IntrotoHistoapthology, p.22]] [[W3 IntrotoHistoapthology.pdf#page=23|W3 IntrotoHistoapthology, p.23]] [[W3 IntrotoHistoapthology.pdf#page=24|W3 IntrotoHistoapthology, p.24]] [[W3 IntrotoHistoapthology.pdf#page=25|W3 IntrotoHistoapthology, p.25]] [[W3 IntrotoHistoapthology.pdf#page=26|W3 IntrotoHistoapthology, p.26]] [[W3 IntrotoHistoapthology.pdf#page=27|W3 IntrotoHistoapthology, p.27]] [[W3 IntrotoHistoapthology.pdf#page=28|W3 IntrotoHistoapthology, p.28]]