Non odontogenic cysts or fissural cysts

easily understandable

1. Non odontogenic cyst Dr. MADHUSUDHAN REDDY

2. Cysts which are not related to the odontogenic apparatus . Grouped under Developmental non odontogenic cysts (all cysts are true cysts) Inflammatory non odontogenic cysts (few psuedo cysts)

3. Developmental non odontogenic cysts Fissural cysts or inclusion cysts Occurs along the lines of fusion of various bones and embryonic processes. Derived from epithelial cells which are entrapped between embryonic processes of bones. Fissural cysts occurs either in bone or in soft tissues .

4. Developmental Non odontogenic cysts Intro osseous Nasopalatine duct cyst Median palatal cyst Globulomaxillary cyst Median mandibular cyst Extra osseous/ soft tissue Palatal cysts of neonate Nasolabial cyst Thyroglossal cyst Oral lymphoepithelial cyst Epidermoid and dermoid cyst

5. Intro osseous Nasopalatine duct cyst Median palatal cyst Globulomaxillary cyst Median mandibular cyst

6. Nasopalatine duct cyst Also called as Nasopalatine canal cyst Incisive canal cyst Median anterior maxillary cyst Most common non odontogenic cyst of oral cavity Nasopalatine duct cysts (NPDC) are cysts that originate from epithelial remnants of the nasopalatine duct , which become entrapped during fusion of the palate plates

7. PATHOGENESIS This lesion is considered as a true developmental cyst and it arises usually due to the proliferation and subsequent cystic degeneration of the epithelial remnants remaining after closure of the embryonic nasopalatine duct . Initiating factors may be Trauma Inflammation Bacterial infection

8. CLINICAL FEATURES Age – 4th , 5th and 6th decade Sex – male > female ( 4:1) Site – usually in anterior region of mid palate near opening of the incisive foramen Small, painful swelling Causes pressure sensation on the floor of the nose and displacement of roots of upper central incisors Occasionally, there can be purulent or salty discharge from the lesion Some patient complain of episodic swelling in the soft tissue between the upper central incisor Regional teeth are always vital

9. RADIOGRAPHIC FEATURES A sharply demarcated symmetrical radiolucency in the midline of anterior maxilla Small round or heart shaped radiolucency between the roots of the upper central incisor in the midline with cortical border Displacement of roots of the upper central incisor are commonly seen

10. HISTOPATHOLOGY Cystic cavity – lined by the ciliated columnar or non keratinized stratified squamous epithelium and is backed by a connective tissue capsule Mucous secretary cells seen Sometimes presence of pigments in the lining Lining may be thin or thick and there may or may not be formation of rete pegs in the lining Presence of large nerve and vascular bundle in connective tissue wall

11. Histopathology

12. DIFFERENTIAL DIAGNOSIS Radicular cyst, if it is associated with a pulpally involved tooth Large incisive canal TREATMENT Surgical enucleation via palatal approach.

13. Median palatal cyst Rare fissural cyst Develops from epithelium entrapped along embryonic line of fusion of lateral palatal shelves of maxilla

14. CLINICAL FEATURES Firm or fluctuant swelling of midline of hard palate posterior to palatine papilla Most frequently in young adults Often asymptomatic Some complain of pain or expansion Average size is 2 x 2 cm, sometimes it can be quite large Midline radiolucency without clinical evidence of expansion is probably a nasopalatine duct cyst

15. RADIOGRAPHIC FEATURES Occlusal radiographs demonstrate well circumscribed radiolucency in midline of hard palate Occasional reported cases have been associated with divergence of central incisors

16. HISTOPATHOLOGY Usually lined by stratified squamous epithelium occasionally by psuedostratified ciliated columnar epithelium Dense connective tissue TREATMENT Surgical removal Recurrence should not be expected

17. Globulomaxillary cyst A type of developmental cysts that actually arises in the bone suture between maxilla and premaxilla Develops from as a result of proliferation of the epithelium , entrapped along the line of fusion between maxilla and premaxilla

18. CLINICAL FEATURES Site – between lateral incisir and canine teeth Usually asymptomatic Cause pain and discomfort only when it is secondarily infected. Vitality test is normal for both teeth

19. RADIOGRAPHIC FEATURES Well circumscribed unilocular radiolucency ( inverted pear between apices of teeth ) Roots reveals divergence

20. HISTOPATHOLOGY Cystic cavity – lined by either by a stratified/ pseudostratified ciliated columnar epithelium or thin squamous epithelium Chronic inflammatory cell infiltration present in capsule

21. DIFFERENTIAL DIAGNOSIS Radicular cyst Lateral periodontal cyst Keratocystic odontogenic tumour Odontogenic tumour Ameloblastoma Central giant cell granuloma Apical infection

22. TREATMENT Careful enucleation without damage to adjoining roots of the teeth, followed by primary closure

23. Median mandibular cyst Extremely rare lesion. Disputed origin True developmental condition originating from proliferating epithelial remnants entrapped in the median mandibular fissures.

24. CLINICAL FEATURES Clinically asymptomatic and discovered only during routine radiographic examination. Rarely expands cortical plates Associated teeth are vital RADIOGRAPHIC FEATURES Unilocular , well circumscribed radiolucency . Some can show multilocularity .

25. HISTOLOGICAL FEATURES Thin stratified squamous epithelium lining the lumen thrown into many folds Some time its lined by psuedostratified ciliated columnar epithelium. TREATMENT AND PROGRESS Conservative surgical excision with preservation of associated teeth.

26. EXTRA OSSEOUS/ SOFT TISSUE CYSTS Palatal cysts of neonate Nasolabial cyst Thyroglossal cyst Oral lymphoepithelial cyst Epidermoid and dermoid cyst

27. Palatal cysts of neonate Commonly found in the posterior midline of the hard palate. Arises from epithelial remnants remaining in the stroma after fusion of the palatal processes which meet medially to form palate. Epsteins pearls and Bhons nodules are the terms which are used seperately previosly but now they are used interchangably .

28. CLINICAL FEATURES Presents as multiple yellow white , sessile mucosal papules on midline of posterior hard palate and ocassionally in the anterior soft palate. Clinically identical to gingival cysts of new born . These are larger and less numerous than the gingival cysts of alveolar process. Very superficial and can be ruptured at the time of examination.

29. HISTOLOGICAL FEATURES Thin stratified squamous epithelium cyst lining without rete ridges. Fibrovascular connective tissue wall. Cystic lumen is filled with degenerated keratin in the form of concentric layers . TREATMENT No treatment is required Within weeks after birth they rupture to spill their content into oral cavity

30. Nasolabial cyst Also called Nasoalveolar cyts Kelstadts cyst Entirely soft tissue cyst , which arises in the nasolabial fold, just below the ala of nose . Occurs in upper lip lateral to the midline . Pathogenesis is uncertain.

31. 2 theories 1 st : considers nasolabial cyst to be fissural cyst Arising from epithelial remnants entrapped along line of fusion of maxillary, medial nasal and lateral nasal process 2 nd : cyst developed from misplaced epithelium of nasolacrimal duct . Due to similar location and similar histologic appearance.

32. CLINICAL FEATURES Swelling of upper lip lateral to midline Result in elevation of ala of nose Enlargement often elevates mucosa of nasal vestibule – obliterates maxillary fold. On occasion, expansion may result in : nasal obstruction, interfere with wearing of denture Pain is uncommon Cyst may rupture spontaneously or may drain into oral or nasal cavity Commonly seen in adults Peak prevalence in 4 th -5 th decades of life Significant predilection for women

33. RADIOGRAPHIC FEATURES Cyst arises in soft tissues Most cases no radiographic changes are seen Pressure resorption of underlying bone may occur HISTOLOGICAL FEATURES May be lined by psuedostratified goblet cells , or by columnar epithelium which is sometimes ciliated, often with goblet cells, or by stratified squamous epithelium.

34. TREATMENT & PROGNOSIS Complete surgical excision of cyst via intraoral approach Because lesion is often close to floor of nose Sometimes it is necessary to sacrifice portion of nasal mucosa to ensure total removal

35. Thyroglossal duct cyst Also called as Thyroglossal tract cyst

36. Rare but occasional cause of a benign midline neck mass. Basis for this pathology is thyroid gland development It is a result of dilatation of a remnant at the site where the primitive thyroid descends from its origin at the base of the tongue to its permanent location in neck . Failure of subsequent closure and obliteration of this tract predisposes to thyroglossal cyst formation. Occurs before the age of 20

37. CLINICAL FEATURES Palpable asymptomatic midline neck mass at or below the level of the hyoid bone. Moves with swallowing Some patient may have neck or throat pain or dysphagia .

38. HISTOLOGICAL FEATURES This cyst is lined by stratified squamous epithelium, ciliated columnar epithelium . Connective tissue of cyst wall frequently contains small patches of lymphoid tissue , thyroid tissue , and mucous glands. Sometimes nodular collection of sabaceous glands

39. TREATMENT Surgical excision of not only cyst but also the path of tract and branches. Intimate association of the tract with hyoid bone mandates removal of the central portion of the hyoid bone ( sistrunk procedure )

40. EPIDERMAL INCLUSION CYST Also called as Epidermal Cyst Epidermoid Cyst Epithelial Cyst Keratin Cyst Sebaceous Cyst Milia . They are the result of implantation of epidermal elements and its subsequent cystic transformation.

41. CLINICAL FEATURES Asymptomatic Men = Women, 3 rd and 4 th decade mostly Gardner syndrome is an exception; the average patient age at onset is 13 years. Discharge of a foul smelling cheese-like material is common. Pain and tenderness. Oral cysts can cause difficulty in feeding, swallowing, or even speaking . It appears as firm, round, mobile, red to yellowish white subcutaneous nodules of variable size. It is mainly reported from sites of face, trunk, neck, extremities, and scalp.

42. HISTOLOGICAL FEATURES Lined by stratified squamous epithelium with glandular differentiation and is filled with desquamated keratin disposed in a laminar pattern. Distrophic calcification is seen besides it. Pigmented epidermoid cyst have melanin pigment in the wall and a keratin mass. TREATMENT AND PROGNOSIS Surgical removal No recurrence

43. Dermoid cyst Also Called As Dermoid Cystic Tumor Cystic Teratoma Ovarian Cystic Teratoma Cystic Tumor Of Ovary Cystic Tumors Of Omentum Congenital Cyst Of Spine Spinal Dermoid Cysts. A hemartomatous tumor containing multiple sabaceous glands and almost all skin adnexa . It may contain nails, teeth, cartilage like and bone like structures .

44. CLINICAL FEATURES Common areas of occurance are face, neck, scalp, intracranial, perispinal , intra-abdominal cysts such as tumors of the ovary or omentum . Seen all ages Diameter of the lesion is 1-4 cm . Some times can occur in floor of the mouth and tongue too.

45. HISTOLOGICAL FEATURES Lined by an epidermis , like epidermoid cyst. Hair that project into the lumen of the cyst are often present. The dermis of it contains sebaceous glands TREATMENT Surgical excision

46. Inflammatory non odontogenic cysts Salivary cysts Mucous extravasation cyst Ranula Mucous retention cyst Antral cyst Retention cyst of maxillary sinus Surgical ciliated cyst of maxilla Traumatic bone cyst Aneursymal bone cyst Stafne bone cyst Parasitic cyst

47. Mucocele Tissue swelling composed of pooled mucus that escaped into the connective tissue from a severed excretory duct . This mucous escape phenomenon is called as mucocele ( extravasation ) Occurs secondary to trauma 70% occurs in lower lip (minor salivary glands) Mucocele of major salivary glands are rare Mucocele formed in the floor of the mouth as a consequence of severence of duct of sublingual gland( ranula ) Submandibular duct severence causes massive extravasation of mucous into submandibular , submental , sublingual regions causing plunging ranula

48. Clinical features: Children and young adults Male and female are equally affected Lower lip is most affected area Buccal mucosa>floor of the mouth> ventral tongue>palate Mucocele of upper lip are uncommon Appears as a fluctuant mass Superficial masses show Bluish translucent appearance Deep masses – appears as a soft fluctuant submucosal nodule with normal mucosal color After small puncture the swelling heals and re accumulation of mucin leading to reoccurrence

49. Histopathology Circumscribed cavity within the connective tissue Distended epithelium Mucin is walled off by a rim of granulation tissue Cavity is not lined by epithelium – false cyst Mucin appears basophilic Numerous amount of inflammatory cells – neutrophils , foam cell histiocytes ( mucinophages ) The duct which supply secretions to the cavity is called feeder duct

50. Treatment : Excision with removal of associated minor salivary glands to minimize the chance of reccurence . Avoid injury to other glands during primary wound closure.

51. ranula Term used for mucocele occuring in the floor of the mouth The name derived from word RANA, because the swelling resemble the transulucent underbelly of the frog . Presents as a blue dome shaped swelling in the floor of mouth. Larger then mucocele Fill the floor of the mouth and elevate the tongue . Located lateral to the midline distinguishing from dermoid cyst (midline).

52. Plunging ranula or cervical ranula Occurs when spilled mucin dissects through the mylohyoid muscle and produces swelling in the neck

53. Treatment: Marsupilization ( deroofing ) Sublingual gland removal via intraoral approach

54. Mucus retention cyst Swelling caused by an obstruction of a salivary gland excretory duct resulting in an epithelial lined cavity containing mucus

55. Clinical features Major salivary glands – parotid is most commonly involved Minor salivary glands Floor of the mouth> buccal mucosa> lower lip Clinically mucocele and mucus retention cyst are indistinguisable . Common in adults Painless, cystic, fluctuant and superficial

56. Histopathology: Treatment: Simple excision Recurrence is rare

57. ANEURYSMAL BONE CYST Primarily seen in long bones or vertebrae , and rarely in jaws. Cause and pathogenesis are not yet clear . Controversy – whether it arises de novo or occurs as a result of some “ vascular accident ” in a pre-existing lesion . Aneurysmal bone cyst is an intraosseous accumulation of variable sized, blood filled spaces surrounded by cellular fibrous connective tissue that is often admixed with trabeculae of reactive woven bone .

58. Pathogenesis is not clear, but some investigators believe that it arises from a traumatic event , vascular malformation , or neoplasm that disrupts the normal osseous hemodynamics and leads to an enlarging, hemorrhagic extravassation . An aneurysmal bone cyst may form when an area of hemorrhage maintain connection with the disrupted feeding vessels, subsequently, giant cell granuloma like area can develop after loss of connection with the original vascular source.

59. CLINICAL FEATURES Age incidence: First 3 decades . Sex incidence: Mainly females . Site predilection: molar regions of mandible & maxilla .

60. Signs & symptoms: Hard, rapidly growing swelling which can cause malocclusion . Mobility of teeth Migration of teeth Root resorption Pain is often present. Paresthesia is present If lesion perforates cortical plates, can cause “ egg shell crackling ”.

61. RADIOLOGICAL FEATURES Classically seen as a unilocular , ovoid / fusiform radiolucency which balloons the cortical plates. Teeth displacement and root resorption also observed.

62. HISTOLOGICAL FEATURES: Cyst cavity shows many capillaries and blood filled spaces , of various sizes separated by delicate loose CT. Blood filled spaces are not lined by endothelium . Many small multinucleated giant cells and trabeculae of osteoid / woven bone cab be seen.

63. Key features Rare in jaws Jaw lesions are mostly seen in ramus and angle region Affected patient usually between 10 and 20 years . Unknown etiology . Soap- bubble radiolucencies –mistaken – ameloblastoma or OKC. Histologically consist of a mass of blood-filled spaces with scattered giant cells . Treated by curettage , but sometimes recur .

64. SIMPLE BONE CYST Synonyms: Solitary / Traumatic / Hemorrhagic bone cyst The simple bone cyst is a benign , empty , or fluid containing cavity within bone that is devoid of an epithelial lining . Commonly seen in mandible , rare in maxilla. Identical to solitary bone cyst of humerus in children and adolescents.

65. PATHOGENESIS None of the theories are certain about exact cause. First theory – cyst may follow trauma to bone that is insufficient to cause fracture which results in intra medullary hemorrhage which fails to organize and repair . This clot subsequently liquefies - resulting in CYST. Recent theory – osteogenic cells fail to differentiate locally and thus instead of bone, the undifferentiated cells form synovial tissue.

66. CLINICAL FEATURES Age incidence: Young individuals 10-20 yrs Sex incidence: Equal Site predilection: Body and symphysis of mandible .

67. Signs & symptoms: Asymptomatic. Rarely, swelling, pain & paresthesia may be seen. Common in premolar and molar region of mandible Half of all patients give a history of trauma to the area.

68. RADIOGRAPHICAL FEATURES Appears as a radiolucency with irregular but well defined edges and slight cortication. When many teeth involved – radiolucency scallops between roots . Teeth involved in lesion – usually vital, no root resorption seen.

69. HISTOLOGICAL FEATURES Wall shows loose fibrovascular CT. Hemorrhage and hemosiderin pigment usually present. Multinucleated giant cells scattered within the CT. Adjacent bone shows osteoclastic resorption on inner surface .