Pathology Lecture 2024 Upper GI Pathology.pdf

RCSI Royal College of Surgeons in Ireland Coláiste Ríoga na Máinleá in Éirinn Upper GI Pathology Class Year 2 Course Pathology Lecturer Dr Katherine Sheehan Date 09th September 2024 LEARNING OUTCOMES Describe Normal Anatomy/Structure of Mouth a...

RCSI Royal College of Surgeons in Ireland Coláiste Ríoga na Máinleá in Éirinn Upper GI Pathology Class Year 2 Course Pathology Lecturer Dr Katherine Sheehan Date 09th September 2024 LEARNING OUTCOMES Describe Normal Anatomy/Structure of Mouth and Oesophagus and Stomach Describe benign and malignant tumours of the oropharynx, oesophagus and stomach Identify the conditions of the Mouth Identify the causes of Salivary Gland Enlargement Identify the causes of oesophagitis and gastritis Define Barrett's oesophagus  Part A Oesophagus Mucosa – Epithelium and lamina propria (a thin layer of loose connective tissue beneath the epithelium) – Squamous epithelium Submucosa – Supportive connective tissue, blood vessels and nerves Muscle Layer Adventitia – In oesophagus = connective tissue Histology: a text and atlas; Michael H. Ross et al; 3rd edition  Symptoms Dysphagia = difficulty swallowing – caused by 4 categories of issues 1. Lesions in the lumen – Foreign body, carcinoma 2. Lesions in the wall – Tumours, scleroderma, strictures 3. Lesions outside the wall – Tumours, aortic aneurysms, lymphadenopathy 4. Lesions affecting function – achalasia  Oesophageal Anatomic Disorders 1. Developmental Abnormalities - Atresia/Fistula – Often associated with pulmonary abnormalities, ‘trachea- oesophageal fistula’ – Several variations possible Oesophagus  2. Acquired Abnormalities Diverticula – ‘True’ – all 4 layers – ‘False’ – only mucosa, submucosa – Pulsion vs Traction Pulsion is due to pressure Traction due to local pathology – Mediastinal Adenopathy Webs/Rings – Webs – Mucosal folds Thin membrane, 2-3mm – Rings – Mucosa, submucosal and fibrous bands  Hiatus Hernia 1-20% of adults Separation of the diaphragmatic crura 2 anatomic patterns: – Sliding (axial) 95% – Paraoesophageal (non axial) Hiatus hernia Reflux Ulceration  Oesophageal Motor Disorders  Achalasia ‘Failure to relax’ – involves 3 major abnormalities 1. Aperistalsis 2. Lower oesophageal sphincter – incompletely relaxes during swallowing 3. Increased resting tone of lower oesophageal sphincter – Can be due to primary loss of inhibitory innervation to the sphincter – This produces a functional obstruction of the oesophagus with dilation of the proximal portion Achalasia  Achalasia Primary Causes – Neural Imbalance between inhibition and activation of the neurotransmitters Degenerative: Intrinsic/Extrinsic Diabetes Secondary Causes – Infectious Trypanosoma Polio – Infiltration Tumour Amyloidosis Sarcoidosis  Oesophagus – other abnormalities Oesophageal Perforation – Most commonly follows instrumentation – Tearing of lower oesophagus after severe vomiting – ‘Mallory-Weiss’ tear - longitudinal – Complicated by mediastinitis Oesophageal Varices – Dilated veins in the submucosa of oesophagus, may rupture and bleed – Portal hypertension Portal flow diverted Occurs in 2/3 of cirrhotic patients Mallory Weiss Tear - tear in the mucosal layer at the OG junction  Oesophageal Inflammatory Disorders Infective: – Fungal – Candida albicans – Viral – Herpes, CMV Physical – Irradiation – Caustic agent ingestion Reflux Raised abdominal pressure Hiatus hernia Smoking Alcohol  Reflux oesophagitis Normal Reflux 3 features histologically: Basal cell hyperplasia occurs to protect the mucosa, with increased eosinophils and elongated lamina propria papillae  Oesophagogastric Junction Lower end of oesophagus – Junction between oesophagus and stomach Between squamous and glandular mucosa Squamous mucosa: – Good for protecting against physical trauma (e.g. hot drinks, rough food) Glandular mucosa: – Mucus – Good for protecting against acid  Metaplasia Chronic acid exposure to the lower end of the oesophagus: – It adapts by changing from: Squamous mucosa → glandular mucosa i.e. Metaplasia In the oesophagus this is called Barrett’s oesophagus – >3 cms of columnar epithelium = long-segment Barrett’s –