GI Flashcards
T106 What is an aphthous ulcer?
A painful ulcer in the oral mucosa with a grayish base and erythematous rim. Self-resolving in a few days, but tends to recur. Linked to inflammatory bowel disease or Behçet syndrome.
What causes herpes simplex in the oral cavity?
Caused by HSV1 (most common) or HSV2, presenting as grouped vesicles on an erythematous base. Reactivates from the trigeminal ganglion following stress or illness.
Describe oral candidiasis
Caused by Candida albicans in immunosuppressed patients or those with disrupted flora. Appears as a gray to white pseudomembrane that can be scraped off. Early sign of AIDS.
What is a fibroma?
A submucosal nodular fibrous tissue mass caused by chronic irritation, commonly found on the buccal mucosa. Appears as a smooth pink nodule.
What is a pyogenic granuloma?
An erythematous, hemorrhagic, exophytic mass usually found on the gingiva of children and young adults. Richly vascular and often ulcerated.
Define leukoplakia.
A white plaque that cannot be scraped off, often caused by hyperkeratosis. Associated with tobacco use and may transform into squamous cell carcinoma.
Define erythroplakia.
Red, granular, circumscribed areas with marked epithelial dysplasia. Has a high risk of malignant transformation, with over 50% of cases becoming cancerous.
What are the risk factors for oral squamous cell carcinoma?
Leukoplakia, erythroplakia, tobacco use, alcohol abuse, chronic irritation, HPV16 and HPV18, and immune suppression.
Where are squamous cell carcinomas most commonly found in the oral cavity?
The ventral surface of the tongue, floor of the mouth, and lower lip.
Describe the morphology of oral squamous cell carcinoma.
White to gray circumscribed thickenings of the mucosa, developing from dysplastic precursor lesions. Histologic patterns range from well-differentiated keratinizing neoplasms to anaplastic tumors.
What are the clinical features of oral squamous cell carcinoma?
50% mortality rate within 5 years. Causes local pain or difficulty in chewing, may be asymptomatic, and can metastasize to cervical nodes, mediastinal nodes, lungs, and liver.
What are the major and minor salivary glands?
Major salivary glands are the parotid, submandibular, and sublingual glands. Minor salivary glands are distributed throughout the mucosa.
What is xerostomia?
Xerostomia is defined as a dry mouth resulting from decreased production of saliva. It is a major feature of Sjögren syndrome and can lead to increased dental caries, candidiasis, and difficulty swallowing and speaking.
What causes sialadenitis?
Sialadenitis is inflammation of the major salivary glands due to trauma or infections. It can be viral (e.g., mumps affecting the parotid gland), bacterial (e.g., S. aureus), or autoimmune (e.g., Sjögren syndrome).
What are the complications of mumps in adults?
In adults, mumps can cause pancreatitis or orchitis (inflammation of the testis).
Describe a mucocele.
A mucocele is a cyst-like space resulting from blockage or rupture of a salivary gland duct, leading to saliva leaking into surrounding tissue. It is lined by inflammatory granulation tissue or fibrous connective tissue and filled with mucin and inflammatory cells.
What is bacterial sialadenitis, and what causes it?
Bacterial sialadenitis is inflammation of the salivary glands occurring secondarily to ductal obstruction due to stone formation (sialolithiasis) or after retrograde entry of oral cavity bacteria (e.g., S. aureus, S. viridians).
How common are salivary gland neoplasms, and where do they most often occur?
Salivary gland neoplasms are relatively uncommon, representing less than 2% of all human tumors. About 80% of these tumors occur within the parotid glands, usually in individuals aged 60-70 years.
What is the relationship between the size of the salivary gland and the likelihood of malignancy?
The likelihood that a salivary gland tumor is malignant is inversely proportional to the size of the gland. Smaller glands have a higher likelihood of malignancy (e.g., sublingual glands).
What is the most common tumor of the parotid gland, and what is the most common malignant salivary gland tumor?
The most common tumor of the parotid gland is pleomorphic adenoma, while the most common malignant tumor of the salivary glands is mucoepidermoid carcinoma.
Describe pleomorphic adenoma
Pleomorphic adenoma arises at the superficial parotid, causing a painless, mobile swelling at the angle of the jaw. It consists of a mixture of ductal (epithelial) and myoepithelial cells, exhibiting both epithelial and mesenchymal differentiation, hence the name “mixed tumor.” It appears as a rounded, well-demarcated mass with a characteristic heterogeneity of epithelial cells or myoepithelial cells within a mesenchyme-like background.
Describe mucoepidermoid carcinoma
Mucoepidermoid carcinoma is the most common primary malignant tumor of the salivary glands, composed of variable mixtures of squamous cells and mucus-secreting cells. Morphologically, it is a well-circumscribed, gray tumor often containing small cysts with mucin. Microscopically, it shows clusters of mucous, squamous, and intermediate cells.
T107 What are the causes of mechanical obstruction in the esophagus?
Mechanical obstruction in the esophagus can be caused by developmental abnormalities, fibrotic stricture, or tumors. Common conditions include atresia and esophageal stenosis.
Describe esophageal atresia.
Esophageal atresia is a condition where a thin, noncanalized cord replaces a segment of the esophagus. It most commonly occurs at or near the tracheal bifurcation and is often associated with a fistula connecting the esophagus and the bronchus/trachea.