This document discusses and compares different types of non-odontogenic (not related to teeth) cysts. It separates them into developmental and inflammatory cysts. Developmental cysts form due to epithelial cell remnants becoming trapped during embryonic development, while inflammatory cysts form due to duct obstruction or trauma. Some examples of developmental cysts mentioned are nasopalatine duct cysts, median palatal cysts, and dermoid cysts. Inflammatory cysts include mucoceles, ranulas caused by salivary gland duct obstruction, and retention cysts of the maxillary sinus. The document provides details on pathogenesis, clinical features, histopathology, diagnosis and treatment of several of these cyst types.

1. Non odontogenic cyst
Dr. MADHUSUDHANREDDY

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. DevelopmentalNon 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
• 1st : considers nasolabial cyst to be fissural cyst
• Arising from epithelial remnants entrapped along line of
fusion of maxillary, medial nasal and lateral nasal process
• 2nd : 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 4th -5th 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, 3rd and 4th 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

49. • 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

51. • 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

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

55. 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).

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

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

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

60. • 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

61. • Histopathology:
• Treatment:
• Simple excision
• Recurrence is rare

62. 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.

63. • 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.

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

65. • 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”.

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

67. • 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.

69. • 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.

70. 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.

71. • 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.

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

73. • 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.

74. • 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.

75. • 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.