نيو مايكروسوفت

• Cysts


  Epithelium-lined pathological cavities, usually filled with fluid, semi-solid material, or cellular debris
• Fissural cyst


  Also called inclusion cyst, because they arise from embryonic epithelium that become entrapped during embryogenesis
• Cysts


  • Clinically present as a soft or fluctuant swelling
• Types of cysts


  • Odontogenic cysts
  • Nonodontogenic cysts
  • Pseudocysts
  • Neck cysts
• Pseudocysts


  Differ from true cysts in that they lack an epithelial lining
• Nasolabial cyst


  Rare developmental soft-tissue cyst that develops in the upper lip in the canine region
• Theories on the etiology of nasolabial cysts

  • Fissural cyst arising from epithelial remnants entrapped along the line of fusion of the maxillary, medial nasal and lateral nasal processes
  • Develop from misplaced epithelium of the nasolacrimal duct
• Nasolabial cyst


  • Appears as a soft-tissue swelling in the mucobuccal fold of the maxilla, lateral to the midline
  • Occasionally causes nasal obstruction, discomfort, or difficulties in wearing dentures
  • More common in women, usually between 40 and 50 years of age
  • In most cases there are no radiographic changes, but resorption of the underlying bone may occur
• Nasopalatine duct cyst


  The most common non-odontogenic cyst of the oral cavity
• Nasopalatine duct cyst


  Arises from epithelial rests in the incisive foramen
• Nasopalatine duct cyst


  • Appears as a slow-growing soft swelling of the palatine papilla, covered with normal mucosa
  • May become inflamed and painful due to local infection
  • Radiographically demonstrates a well circumscribed radiolucency in or near the midline of the maxilla, between and apical to the central incisor teeth
  • A diameter of 6 mm or smaller in this area is usually considered a normal foramen unless other clinical signs and symptoms are present
• Epithelial lining of nasopalatine duct cyst


  • Stratified squamous epithelium
  • Pseudostratified columnar epithelium
  • Simple columnar epithelium
  • Simple cuboidal epithelium
• Globulomaxillary cyst


  Once considered a fissural cyst, located between the globular and maxillary processes, but now thought to be of odontogenic origin
• Globulomaxillary lesion


  • Appears as a well-defined radiolucency, often producing divergence of the roots of the maxillary lateral incisor and canine teeth
• Radicular cyst and periapical granuloma can be ruled out with pulp vitality testing
• Oral lympho-epithelial cyst


  Uncommon developmental lesion of the oral mucosa
• Etiology of oral lympho-epithelial cyst

  Probably caused by cystic degeneration of glandular or surface epithelium entrapped in lymphoid tissue during embryogenesis
• Oral lympho-epithelial cyst


  • Presents as an asymptomatic, mobile, well-defined nodule, usually firm on palpation and elevated, with a yellowish or whitish color
  • Size ranges from 0.5 cm to 2 cm in diameter
  • Most frequent location is the floor of the mouth, followed by the posterior lateral border and the ventral surface of the tongue
• Thyroglossal duct cyst


  Rare developmental lesion that may form along the thyroglossal tract
• Etiology of thyroglossal duct cyst


  Remnants of thyroglossal duct epithelium
• Thyroglossal duct cyst


  • Usually located under the hyoid bone but can be located anywhere from the suprasternal notch to the foramen cecum of the dorsal tongue
  • Intraorally, appears as a painless, fluctuant swelling usually 1–3 cm in diameter, located in the midline of the dorsum of the tongue close to the foramen cecum
  • Occasionally, a fistula may form following infection
  • Most often diagnosed in patients less than 20 years of age
• Epithelial lining of thyroglossal duct cyst


  • Stratified squamous
  • Columnar
  • Small intestinal epithelium
  • Mixture of these
• Median mandibular cyst


  Once considered a fissural cyst, but now thought to be of odontogenic origin
• Median mandibular cyst


  • Appears as a swelling in the midline of the mandible
  • Radiographically appears as a well circumscribed radiolucency between the two lower central incisors in the midline
• Epithelial lining of median mandibular cyst

  • Mainly stratified squamous
• Median palatal cyst


  Rare fissural cyst that develops from epithelium entrapped along the embryonic line of fusion of lateral palatal shelves
• Median palatal cyst


  • Present as a firm or fluctuant swelling in the midline of the hard palate posterior to the palatine papilla
  • Radiographically appears as a well-circumscribed radiolucency in the midline of the hard palate
• Epithelial lining of median palatal cyst


  • Stratified squamous epithelium
  • Areas of ciliated pseudostratified columnar epithelium may be present
• Dermoid and epidermoid cysts


  Represent a simple form of cystic teratoma derived from skin epithelium entrapped during embryonic development
• Dermoid and epidermoid cysts


  • Mostly occur in the head & neck region, primarily in the skin around the eyes & the anterior upper neck, extending superiorly into the floor of the mouth
  • Present as painless swelling exhibiting a doughy consistency on palpation, and may cause elevation of the tongue and interfere with eating & speaking
• Histology of dermoid and epidermoid cysts


  • Lined by a layer of orthokeratinized squamous epithelium, surrounding by connective tissue capsule
  • Dermoid cysts also exhibit variable numbers of dermal appendages including hair follicles, sebaceous glands
• Stafne bone cyst


  • Also known as lingual mandibular bone cavity, static bone cavity, and lingual salivary gland defect
  • An asymptomatic lesion
• Stafne bone cyst


  • Radiographically appears as a solitary radiolucency below the inferior alveolar canal near the angle region of the mandible
  • The lesion is usually oval and exhibits no growth over long periods of time
  • The periphery is smooth and symmetric
  • The lesion is benign, has no growth potential, and a classic radiographic appearance that makes diagnosis without biopsy possible and observation without active intervention the treatment of choice
• Submandibular salivary gland depression


  An incidental finding, not a true cyst
• Submandibular salivary gland depression


  • Radiographically appears as a small, circular, corticated radiolucency below the mandibular canal
  • Histologically shows normal salivary tissue
  • Treated with routine follow up