Head And Neck Flashcards
How is the oral cavity characterized histologically and what are the different types of lesions?
Histologically the oral cavity is characterized by a non keratinized squamous epithelium on the soft plate, inner lips, inner checks, floor of the mouth and ventral surface of the tongue. The keratinized portions are found in the gengiva, hard palate and dorsal surface of the tongue.
Diseases of the oral cavity can be classified as either inflammatory/reactive lesions or neoplastic ones.
what are the two most common oral cavity inflammatory lesion?
• Gingivitis : It is the inflammation of the oral mucosa surrounding the teeth. It is a result of poor dental hygiene and leads to the accumulation of plaque which is a sticky colorless biofilm contains bacteria, salivary proteins and epithelial cells. If it is not removed in can calcify leading to gingival erythema, bleeding and loss of soft tissue.
• Periodontitis : It is an inflammatory process that affects the supporting structures of the teeth, alveolar bone and cementum. It can lead to complete destruction of periodontal ligament, loosening of teeth. It is associated with a change is bacteria proportions and types along the gingiva. These infections can become the origin of other diseases such as Infective Endocarditis.
What are Fibrous Proliferating lesions?
Inflammatory lesions. For example an Irritation Fibroma which is a submucosal nodular mass of fibrous CT. It is believed to be caused by repetitive trauma. Surgical excision is curative. Also Pyogenic Granulomas are inflammatory lesions typically found in children and pregnant women. They are hugely vascularized and are not considered precancerous. The name itself is misleading as they are not pus forming (pyogenic) and are not granulomas but rather a capillary hemangiomas, that is why it is prone to bleeding.
What are other complications of the oral cavity?
• Infections : Herpes Simplex virus infection or Oral Candidiasis which is the most common fungal infection. The most common type of candida albicans infection is pseudomembranous. Characterized by a whitish membrane and it can be readily scraped off to reveal an underlying erythematosus inflammation
What is Hairy Leukoplakia?
Hairy Leukoplakia which is a lesion on the lateral border of the tongue seen in immunocompromised patients and is caused by EBV. Takes the form of white fluffy patches, hyperkeratotic thickenings. The lesion cannot be scraped off unlike thrush.
What are some pre cancerous lesions in the oral cavity?
Leukoplakia : It is a white patch that cannot be scraped off and it cannot be characterized clinically or pathologically as any other disease. Until proven otherwise all the leukoplakia‘s must be considered pre-cancerous. They can occur anywhere in the oral cavity and appear as solitary or multiple white patches. Histologically they present a wide variety of epithelial changes.
Erythroplakia : it is a less common variant of leukoplakia, it is red and velvety. The risk of malignant transformation is much higher than in leukoplakia almost all erythroplakias demonstrate severe dysplasia, carcinoma in situ or minimally invasive carcinoma.
What carcinoma can we find in the oral cavity?
Squamous Cell Carcinomas are 95% of head and neck tumors, with the remainders being adenocarcinoma of salivary gland origin. It most commonly occurs in the oropharynx particularly involving the tonsils, base of tongue and pharynx. Many of them harbor oncogenic variants of HPV. The five year survival rate of a classic early stage SCC is 80%. The main molecular alterations involve the p53 pathway as well as other proteins responsible for squamous differentiation such as p63 and NOTCH 1. Histologically they begin as dysplastic lesions and range from well differentiated keratinized neoplasms to anaplastic tumors. They spread through lymphatic route, always through the mediastinal LNs.
What are some common inflammations of the upper airways?
Infectious rhinitis, allergic rhinitis, nasal polyps and sinusitis.
What is sino nasal papilloma?
Most frequent tumor. Benign neoplasm arising from respiratory mucosa lining the nasal cavity. Generally they are associated with HPV6 and HPV1. They can grow lesions like polyploids which are visible and inverted growth.
What is an olfactory neuroblastoma?
They arise from the neuroectodermal olfactory cells present within the epithelium in the superior aspect of the nasal cavity. The patients usually presents with nasal obstruction and nose bleeding. Histologically they are composed of well circumscribed cells separated by fibrovascular stroma. Because they are of neuroendocrine origin they express synaptophysin, CD56 and chromogranin.
What is a NUT midline carcinoma?
Rare tumor that may occur in the nasopharynx, salivary glands or other midline structures. Composed of large cells often mistaken for SCC but unlike it there are no lymphocytes rather very primitive and undifferentiated cells. It is extremely aggressive and resistant to conventional therapy. Associated with translocations that causes the fusion of BRD4 and NUT genes the first is a chromatin reader and the second in a chromatin regulator.
What is a nasopharyngeal carcinoma?
It is associated with EBV and particularly common in some parts of Africa. There are three types ; Keratinizing SCC which is undistinguishable from a common squamous cell carcinoma, the only correct way to diagnose it is considering its location and association with EBV, Non Keratinizing SCC, and Undifferentiated/Basaloid Carcinomas.
What is laryngeal squamous papilloma?
Benign neoplasms located on the vocal cords, that form raspberry like proliferation rarely more that 1 cm in diameter. They are made of multiple slender finger like projections covered by a stratified squamous epithelium. Not necessarily liked to HPV6 or HPV1, they do not become malignant.
Laryngeal carcinoma?
it is most commonly a SCC, typically in male chronic smokers in their 60s. It follows the typical growth pattern of other SCCs, starts from hyperplasia, followed by atypical hyperplasia, dysplasia, carcinoma in situ and invasive carcinoma. Usually develops on vocal cords but may arise above or below the cords as well or on the epiglottis.
What is a paraganglioma?
Aka Carotid body tumor. :Paraganglia are clusters of neuroendocrine cells associated with the sympathetic and parasympathetic nervous system’s. These neoplasms can be seen in various regions of the body but are mostly considered malignant legions of the neck. They typically develop in either Paravertebral Paraganglia or Paraganglia related to great vessels of the head and neck. To diagnose a paraganglioma there must be both chief cells and sustentacular cells. The carotid body tumor is a lesion of 6 cm and arises close to the bifurcation fo the common carotid artery, they are composed of chief cels that stain for synaptophysin and CD56 and supported by a network of sustentacular cells.
