NON ODONTOGENIC CYSTS

Oral pathology presentation

1. NON ODONTOGENIC CYSTS

2. WHAT ARE NON ODONTOGENIC CYSTS ? According to Shafer's Cysts in the orofacial region not essentially derived or related to the odontogenic apparatus are called non odontogenic cysts.

3. Non odontogenic cysts are grouped into DEVELOPMENTAL and INFLAMMATORY CYSTS. All the developmental non odontogenic cysts are true cysts (i.e. pathological cavity lined by the epithelium, usually containing fluid or semisolid material) All the inflammatory non odontogenic cysts are pseudo cysts.

4. Classification of Non Odontogenic cysts DEVELOPMENTAL INTRAOSSEOUS Nasopalatine duct cyst Median palatal cyst Globulomaxillary cyst Median mandibular cyst EXTRAOSSEOUS Palatal cyst of newborn (Epstein’s nodule) Nasolabial cyst Thyroglossal duct cyst Oral lymphoepithelial cyst Epidermoid cyst Dermoid cyst INFLAMMATORY Traumatic Salivary cyst Antral cyst Traumatic bone cyst Aneurysmal bone cyst Infectious Parasitic cyst

5. INTRAOSSEOUS DEVELOPMENTAL NON ODONTOGENIC CYST

6. OTHER NAMES : Median anterior cyst Midline maxillary cyst Anterior median palatine cyst Incisive canal cyst Incisor duct cyst Most common intraosseous , non- odontogenic cyst of jaw (maxilla ) NASOPALATINE DUCT CYST

7. Occurs in ~1% of population Represents 1.7-11.9% of all jaw cysts Usually adults, peak prevalence in fourth and fifth decades More common in males (ranges in literature from slightly more common to up to 3x more common in males than females EPIDIMIOLOGY :

8. SITE : Exclusively in maxilla, located in anterior midline of hard palate Occasionally can produce a midline anterior maxillary swelling if cyst erodes bone of anterior maxilla Cysts can form within the incisive canal located in palatine bone behind alveolar process of maxillary central incisors Some doubt the existence of  median palatine cyst  as a distinct entity and characterize all non- odontogenic cysts of the midline maxilla regardless of anterior or midline location, as nasopalatine duct cysts Rarely, may develop within incisive papilla, the anterior soft tissue protuberance that overlies the incisive foramen In this instance, is termed cyst of incisive papilla , or cyst of palatine papilla

9. ETIOLOGY : Two main theories : First : originates from spontaneous proliferation of remnants of nasopalatine duct within incisive canal Exact trigger that stimulates development is unknown, but factors proposed include trauma and infection Second: theory now out of favor; originates from trapping of epithelial remnants during embryologic fusion between nasal cavity and anterior maxilla

10. Usually asymptomatic, may have swelling of palate in relation to maxillary central incisors Occasionally produces a midline anterior maxillary swelling if cyst erodes bone of the anterior maxilla Can present with painful swelling or drainage, or tooth root displacement Salty taste in mouth and devitalisation of pulp of associated teeth CLINICAL FEATURES :

11. HISTOLOGY : Lined by stratified squamous epithelium alone or with pseudostratified columnar epithelium (variable cilia and goblet cells), simple columnar epithelium or simple cuboidal epithelium Cyst wall is composed of fibrous tissue with nerves, cartilaginous rests, arteries and veins The nasopalatine duct contains the nasopalatine nerve and the terminal branch of the descending palatine artery

12. RADIOLOGY well-circumscribed radiolucency in or near midline of anterior maxilla between apical to central incisor root resorption is rarely noted lesion most often is round or oval with a sclerotic border some cases, a classic heart shape a s a result of superimposition of nasal spine OR because they are notched by nasal septum

13. radiographic diameter can range from small lesions, less than 6 mm to destructive lesions as large as 6 cm most cyst are in range 1.0- 2.5 cm, with average diameter of 1.5-1.7 cm radiolucency that is 6 cm or smaller in this area is usually considered a normal foramen unless other clinical signs or symptoms are present

14. DIFFERENTIAL DIAGNOSIS Glandular odontogenic cyst : Intraosseous developmental odontogenic cyst, may have ciliated or mucous cells within cystic lining Should NOT have contents of incisive foramen (peripheral nerve, cartilaginous rests, muscular vascular channels) Nasolabial ( nasoalveolar ) cyst : Soft tissue (non- intraosseous ) cyst with histologic features similar to nasopalatine cyst Occurs in soft tissues of upper lip lateral to midline Should not have contents of incisive foramen (peripheral nerve, cartilaginous rests, muscular vascular channels)

15. Periapical (radicular) cyst : Most common inflammatory odontogenic cyst Lined by stratified squamous epithelium of variable thickness, often with scattered ciliated cells Derived from rests of Malassez In nasopalatine cysts, the lamina dura is intact and the pulp is usually vital, but radicular cysts are associated with a pulpless tooth and involve a portion of the root, usually with loss of continuity of the lamina dura Surgical ciliated cyst: Post-operative "complication" with cystic expansion of respiratory epithelium within maxilla, may have ciliated or mucous cells within cystic lining Usually located in posterior maxilla, and lacks contents of incisive foramen (peripheral nerve, cartilaginous rests, muscular vascular channels)

16. S urgical enucleation B iopsy is recommended because lesion is not diagnostic radiographically benign + malignant lesions have been known to mimic nasopalatine duct cyst Palatal flap reflected after incision - made along lingual gingival margin of anterior maxillary teeth Recurrence is rare TREATMENT

17. rare fissural cyst develops from epithelium entrapped along embryonic line of fusion of lateral palatal shelves of maxilla Also known as Median Palatine cyst MEDIAN PALATAL CYST EPIDIMIOLOGY Rare, only 21 cases have been reported in the literature (4 after 1992) Although limited numbers, more common in males ( 4:1)

18. SITE : Midline of the hard palate between lateral palatal processes ETIOLOGY : Controversial, and the existence of the cyst itself has been questioned Originally thought to arise from remnants of epithelium entrapped during fusion of facial processes during embryogenesis, specifically the lateral palatal shelves More recently, the 1992 WHO wrote "it is now felt that those [cysts] in the maxilla represent a posterior extension of the nasopalatine duct cyst in the case of a median palatine cyst" ( WHO: Histological Typing of Odontogenic Tumours , 1992 )

19. firm or fluctuant swelling of midline of hard palate posterior to palatine papilla most frequently in young adults often asymptomatic Some complain of pain and expansion average size is 2 x 2 cm, sometimes it can be quite large must be stressed out that a true medial palatal cyst should exhibit clinical enlargement of palate midline radiolucency without clinical evidence of expansion is probably a nasopalatine duct cyst CLINICAL FEATURES :

20. O cclusal radiographs demonstrate well- circumscribed radiolucency in midline of hard palate occasional reported cases have been associated with divergence of central incisors RADIOLOGY :

21. HISTOLOGY : Lining consists of stratified squamous epithelium or pseudostratified ciliated columnar epithelium overlying a relatively dense fibrous connective tissue band which may show chronic inflammatory cell infiltration

22. DIFFERENTIAL DIAGNOSIS : Nasopalatine cyst Nasoalveolar cyst Surgical ciliated cyst

23. surgical removal recurrence should not be expected TREATMENT :

24. GLOBULOMAXILLARY CYST The globulomaxillary cyst has traditionally been described as a fissural cyst. It is found within the bone at the junction of the globular portion of the medial nasal process & the maxillary process, the globulomaxillary fissure, usually the maxillary lateral incisor & cuspid teeth. It is also called ‘ premaxilla-maxillary cyst ’ because of the evidence of its formation in the bone suture between the premaxilla & maxilla.

25. It appears as an inverted, pear-shaped radiolucent area between the roots of the lateral incisor & cuspid, usually causing divergence of the roots of these teeth. The teeth associated with a cyst are vital unless coincidentally infected. RADIOGRAPHIC FEATURES

26. HISTOLOGIC FEATURES The cyst is lined by either stratified squamous or ciliated columnar epithelium. The remainder of the wall is made up of fibrous connective tissue, usually showing inflammatory cell infiltration.

27. TREATMENT This type of cyst should be surgically removed, preserving the adjacent teeth if possible .

28. MEDIAN MANDIBULAR CYST It occur in the midline of the mandible. CLINICAL FEATURES It is clinically asymptomatic. They seldom produce obvious expansion of the cortical plates of bone, and the associated teeth; unless otherwise involved, they react normally to pulp vitality tests.

29. RADIOGRAPHIC FEATURES It is generally of a unilocular , well-circumscribed radiolucency , although it may also appear multilocular .

30. HISTOLOGIC FEATURES Histologic examination of the lesion shows a thin, stratified squamous epithelium, often with many folds & projections, lining a central lumen.

31. TREATMENT The surgical excision with preservation of associated teeth.

32. EXTRAOSSEOUS DEVELOPMENTAL NON ODONTOGENIC CYST

33. PALATAL CYST OF NEONATE (EPSTEIN PEARL, BOHN’S NODULE) Commonly found in post. Midline of the hard palate. It arises from the epi . Remnants remaining in the stroma after fusion of the palatal processes which meet medially to form palate. Two types(on the basis of origin) Epstein pearls-the cyst along the medially raphe of the palate Bohn’s nodule-cyst originated from the palatal gland structure.

34. CLINICAL FEATURES Present as multiple(<6) 1-4 mm, sessile mucosal papules of the post. hard palate and occasionally of the ant. soft palate. Larger and less numerous than the gingival cyst of the alveolar process in newborns. Cyst are superficial and they may rupture at the time of examination.

35. H/F- Palatal cyst of newborn show thin,stratified sqamous epithelium cyst lining with a fibrovascular connective tissue stroma , usually without an inflammatory cell infiltration. Cyst lumen is filled with degenerated keratin,usually formed into concentric layers(like onion rings) and epithelium lacks rete processes.

36. TREATMENT AND PROGNOSIS No treatment required as cyst are very superficial and within weeks will rupture and spill their content into the oral environment, some larger cyst which are situated deeply in the submucosal stroma will remain for 6-8 months. The cyst lining then fuses with the overlying mucosa and becomes part of it.

37. NASOLABIAL CYST (NASOALVEOLAR CYST) It is a rare fissural cyst that may involve bone secondarily. It arises at the junction of the globular process,the lateral nasal process and the maxillary process as a result of proliferation of the entrapped epithelium along the fusion line. It originates from the lower ant. part of nasolacrimal duct.

38. CLINICAL FEATURES Located near the attachment of the ala over the maxilla and may cause swelling in the mucolabial fold as well as in the floor of the mouth. Superficial erosion of outer surface of maxilla is due to pressure produced by the nasolabial cyst. Cyst is three times more common in women.

39. H/F - Cyst may be lined by psuedostratified columnar epithelium which is sometimes ciliated, often with goblet cells or by stratified sqamous epithelium. TREATMENT- the cyst should be surgically excised.

40. THYROGLOSSAL DUCT CYST (THYROGLOSSAL TRACT CYST) Rare, but occasional cause of a benign midline neck mass. Located at the midline of the neck. Most often occurs before age of 20,but may be found in the older population as well. The cyst result from the dilatation of a remnant at the site where the primitive thyroid descended from its origin at the base of the tongue to its permanent location,low in the neck. Failure of subsequent closure and obliteration of thus tract lead to cyst formation.

41. C/F- Cyst present with a palpable asymptomatic midline neck mass at or below the level of the hyoid bone. Neck mass moves with swallowing. It is associated with neck or throat pain or dysphagia. Since the persistent duct or sinus can promote oral secretion, and such cyst become infected. Infection sometimes causes transient appearance of a mass or enlargement of the cyst, at times with periodic recurrences.

42. H/F- Cyst may be lined by stratified sqamous epithelium, ciliated columnar or intermediate transition type. The connective tissue wall of the cyst will frequently contain small patches of lymphoid tissue, thyroid tissue and mucous glands. Treatment - Definitive surgical management requires excision not only of the cyst but also of the path’s tract and branches. It is mandatory to remove the central portion of the hyoid bone to ensure complete removal of the tract. Recurrence is unlikely.

43. The oral lymphoepithelial cyst develops within a benign lyphoid aggregates or accessory tonsil of the oral or pharyngeal mucosa . The surface of such aggregates may be indented with tonsillar crypts , as are the much larger pharyngeal walls . Outside of the head and neck region, lymphoepithelial cyst is found most frequently in the pancreas and testes ORAL LYMPHOEPITHELIAL CYST

44. CLINICAL FEATURES Oral lymphoepithelial cyst present as a movable , painless sub mucosal nodule with a yellow or yellow – yellow white discoloration . Occasional cyst are transparent. They are less than 0.6 cm in diameter. Half of all the intraoral examples are found on the oral floor .Also found in the lateral and the ventral tongue and especially the mucosa above the pharyngeal tonsil . Superficial cyst rupture to release a foul-tasting , cheesy ,keratinous material This cyst has a clinical appearance similar to that of an epidermoid cyst or dermoid cyst of oral/pharyngeal mucosa . The lymphoepithelial cyst never occurs on the alveolar mucosa , hence , can easily be distinguished from the gingival cyst of adult or from an unruptured parulis or pus pocket at the terminus of a fistula

45. HISTOLOGIC FEATURES The lymphoepithelial cyst is lined by atrophic degenerated stratified squamous epithelium , usually lacking rete processes and usually demonstrating a minimal granular cell layer . Orthokeratin is seen to be sloughing from the epithelial surface into the cystic lumen , often completely filling the lumen and sometimes dystrophic calcification . Rarely , mucus –filled goblet cells may be seen within the superficial layers of the epithelium – lined communication with the overlying mucosal surface The cyst is entrapped within a well-demarcated aggregate of mature lymphocytes The combination of epithelium-lined cyst with lymphoid aggregates helps in diagnosis .

46. TREATMENT No treatment is usually necessary for the oral lymphoepithelial cyst unless its location is such that it is constantly being traumatized .

47. EPIDERMOID CYST Also known as epidermal cyst ,epidermal inclusion cyst epithelial cyst, keratin cyst, milia . Epidermal inclusion cyst are the result of implantation of epiermal elemnts and subsequent transformation The term epidermoid cyst is used in a general context in that irrespective of the source of the epithelium. Milia rarely represent miniature epidermoid cyst

48. AETIOLOGY The origin of epidermoid cyst is varied. They may form by sequencestration and implantation of epidermal rest,during embryonal period,occlusion of the pilosebacious unit,surgical implantation of epithelium into the jaw mesenchyme . HPV infection and accrine duct occlusion may be the additional factors in the developement of epidermoid cyst. Epidermoid cyst result from the proliferation of epidermal cells within a circumscribed space of the dermis. The source of the epiermis is oftened the infundibulum of the hair follicle. Inflammation is in part mediated by the horny material conatained in epidermoid cyst.

49. CLINICAL FEATURES Indolent in nature , slow to progress and remain asymptomatic untill or unless secondarily infected Appear firm, round , mobile , flesh coloured to yellow or white subcutaneous nodules of variable size A central pore or punctum is an inconsistent finding that may adhere the cyst to overlying epidermis and form thick cheesy material . Epidermoid cyst may be pigmented . This cyst mainly reported in sites of face , the trunk , the neck , the extremities and the and the scalp . While facial involvement is also frequent in Gardner syndrome Epidermoid cyst are more twice as common in men as in women . Occur at any time in life but more common in third and fourth decades of life . Discharge of foul smelling cheese like material Cyst become inflammed or infected , resulting in pain and tenderness . When located orally they cause difficulty in feeding , swallowing or even speaking

50. HISTOLOGICAL FEATURES The cystic lining is comprised of stratified squamous epithelium with glandular differentiation. and it is filled with desquamated keratin disposed in the laminar pattern. Dystrophic calcification and reactive foreign body reaction are seen associated with cystic capsule Pigmented epidermoid cyst may demonstrate melanin pigment in the wall and a keratin mass. Infiltration of melanocytes and melanophages may also be observed in surroundings. They include intracytoplasmic eosinophillic inclusion bodies in the cyst wall, vacuolated cells and the cells with keratohyalinic granules in the granular layer, elongated reteridges and vacuolated structures and parakeratotic nuclei in the keratinous mass.

51. TREATMENT AND PROGNOSIS Surgical removal seems to be the mainstay in the management protocol Malignancies have identified in epidermoid cyst

52. DERMOID CYST It is also known as dermoid cystic tumour, Cystic Teratoma, Ovarian cystic teratoma, Cystic tumour of omentum and spinal dermoid cyst. It is an hamartomatous tumour containing multiple sebaceous glands and almost all skin adnexa , may contain substances' such as nails an dental cartilage and bone like structures. The origin of this cyst is probably by sequecestration of skin subsequent implantation of it along the lines of embryonic closure.

53. CLINICAL FEATURES Commonly mostly occur on face, neck or scalp In addition to skin dermoid cyst can be intracranial, intraspinal or perispinal. Intra abdominal cyst such as cystic tumour of the ovary or the omentum,occur as well. Mostly occurs in whites. Dermoid cyst are described in the persons of all ages. Intracranial or perispinal dermoid cyst are most often find in infants, children's or young adolescents. Intraabominal dermoid cyst are described in females aged between 15 to 40 years of age. Most dermoid cyst on the floor of the mouth occur in the individual aged between 10 to 30 years. Three subclasses of congenital mouth cyst are epidermoid(simple) cyst, dermoid (complex) cyst and teratoid (complex) cyst. Most of these lesions occur in individual aged between 10 to 30 years of age.

54. HISTOLOGICAL FEATURES Dermoid cyst in the skin are lined by epidermis that possesses various epidermal appendages. Hair follicles containing hair that project into the lumen of the cyst are often present. The dermis of dermoid cyst usually contains sebacious glands , accrine glands and apocrine glands. The lining epithelium may proliferate as papillary boundaries externally or inward toward the lumen of the cyst.

55. TREATMENT AND PROGNOSIS Surgical excision is the treatment of the choice in any localization.

56. INFLAMMATORY NON ODONTOGENIC CYSTS

57. TRAUMATIC INFLAMMATORY NON ODONTOGENIC CYSTS The most common cause leading to the such cysts are physical or mechanical trauma. They can be true or pseudo cyst. All other inflammatory cysts are intraosseous except salivary cysts and parasitic cysts

58. SALIVARY CYST Cysts associated with salivary glands are of two types- 1. Extravasation cyst - Mucocele - Ranula 2. Retention cyst

59. MUCOUS EXTRAVASATION CYST Most common benign lesion of salivary gland Occurs due to rupture of salivary gland or their ducts leading to spillage of mucin in surrounding soft tissue. mucocele - Rupture of minor salivary gland or ducts Smaller the ranula Ranula – Rupture of ducts of submand ./sub lingual gland. larger

60. Traumatic severance produced by biting lip, cheek leading to its development. Mucocele C/F- Common site-lower lip Other sites-upper lip, palate, cheek, tongue,(gland of blandin nuhn ) and floor of mouth. ETIOLOGY

61. LESION Deep Painless swelling Appears as normal mucosa. Superficial Raised, circumscribed vesicle Diameter -(mm-cm) with bluish translucent cast

62. H/F Being a psedocyst,contains areas of spilled mucus within fibrous connective tissue lining. Granulation tissue with inflammatory reaction (macrophages containg phagocytized mucus.) TREATMENT excision with strict removal of any projecting peripheral salivary gland.

63. 2. Ranula - Latin word rana C/F- Slowly developing painless mass on one side of floor of mouth. Blue dome shaped. Elevates the tongue. Lesion-deep seated lesions(with normal appearing mucosa) -superficial lesion(with translucent bluish mucosa)

64. MUCOUS RETENTION CYST True cyst Occurs due to obstruction of constriction of salivary gland duct leading to retention of saliva within duct. AETIOLOGY AND PATHOGENESIS Due to partial or total obstruction of salivary duct by -salivary calculi -mucous plug Continuous use of mouth washes leading to constriction of ductal orifice.

65. Mainly involves major gland such as parotid presenting. Slowly growing, fluctuant and painless swelling. Deeper lesion appear normal, nodular and firm. Superficial lesion appear bluish and vesicular C/F-

66. H/F - Lining epithelium-non keratinised stratified sqamous or columnar epithelium. Lumen may contain eosinophlic material. Lining epi . may undergo oncocytic metaplasia exhibiting papillary folds.

67. HISTOLOGICAL SUBTYPES True mucous retention cyst - lined by nononcocytic ductal epi . With minimum inflammation. Reactive oncocytic cyst - non oncocytoid metaplasia Mucopapillary cysts - with papillary multicystis growth pattern.

68. TREATMENT Surgical excision along with gland.

69. TRAUMATIC BONE CYST Pseudocyst Uncommon comprising about 1% of all jaw cysts May occur in other bones.

70. ETIOLOGY Various theories are given:- 1) Trauma –hemorrhage theory Widely accepted Intramedullary hemorrhagic following traumatic injury Rather than organizing, the clot breaks down, leaving an empty bony cavity. Alternative developmental pathways include cystic degeneration of primary tumors of bone,such as central giant cell granuloma . Disorders of calcium metabolism Ischemic necrosis of bone marrow

71. C/F - Teenagers commonly affected Common sites-post. Portion of mandible commonly involved than ant. (numerous cases in incisor region in young patients as this area contains hemopoetin marrow) Swelling is present occasionally. R/F - Radiolucent area with scalloping borders b/w the roots of teeth. Occasional root resorption Radiolucency usually lie below mand . Canal.

72. H/F - Loose vascular fibrous tissue memb.of variable thickness with no epi . lining. Hemosidrin pigment Multinucleated giant cell tumor present.

73. ANTRAL CYSTS Associated with maxillary antrum Retention cyst of max. sinus Surgical ciliated cyst of maxilla Retention cyst of max. sinus Lesion represents retention phenomenon of mucous gland associated with lining of max. sinus.

74. ETIOLOGY- Blockage of ducts of sero mucous gland of sinus lining. Obstruction of sinus opening, blocking the drainage of sinus secretion. Others-sinusitis, allergy and sinus infection. C/F- Mostly they are asymptomatic. Represents pain and soreness of face and teeth and numness of upper lip. Buccal expansion of max. antrum may also be seen.

75. R/F- Radiopaque lesion of varying density. Appears as soft tissue mass rather than calcified area. Entire sinus may appear cloudy.

76. H/F- Accumulation of fluid within CT space showing epi . Lining Epithelial psedostratified ciliated columnar or stratified squamous with goblet cells. Also called secretory type of antral cyst. Inflammatory infiltrate with CT wall. TREATMENT- No treatment is necessary as it disappears spontaneously with short period.

77. SURGICAL CILIATED CYST ETIOLOGY- Develops either after surgical entry into max. sinus. Damage to floor of sinus due to complicated extraction of upper teeth. Ostial obstruction C/F - Present non specific, poorly localized pain ,tenderness in maxilla. Extra or intra oral swellings may also be seen. Mucopyocele is the lesion where content in the mucocele get infected.

78. Well defined unilocular radiolucent area closed to max. sinus Anatomically separate from it, which can be demonstrated by injecting radiopaque material called filing defect of cyst. H/F- Epithelial lining- pseudo stratified ciliated columnar identical to maxillary sinus. Squamous metaplasia is seen if infection of inflammation is present. R/F-

79. ANEURYSMAL BONE CYST Uncommon; expanding osteolytic lesion of blood filled spaces of variable size separated by connective tissue septa with osteoclast giant cells and variable reactive bone Usually ages 1 - 20 years, no gender preference Benign but grows rapidly; simple curettage is followed by recurrence in 20%; rarely transforms to osteosarcoma May also be secondary to trauma or arise in preexisting bone lesion (giant cell tumor, chondroblastoma , fibrous dysplasia ) Aneurysmal bone cysts are benign lesions that occur predominantly in the metaphyses of tubular long bones; their occurrence in the jaw region is very rare. Although aneurysmal bone cysts are principally benign lesions, they can cause extensive bone destruction when diagnosed at a late stage SITES : metaphysis of posterior vertebrae (often multiple), flat bones, shaft of long bones; rarely within wall of major artery or in soft tissue 

80. PATHOLOGY : 4 phases of pathogenesis : OSTEOLYTIC INITIAL PHASE ACTIVE GROWTH PHASE – Rapid destruction of bone and subperiostal blow out pattern MATURE STAGE – (STAGE OF STABILIZATION)- Formation of a distinct peripheral bony shell and internal bony septa and trabeculae that produce the classic soap bubble like appearance HEALING PHASE – progressive calcification and ossification of cyst and eventual transformation into a dense bony mass with irregular structure

81. HISTOLOGY : Large cystic spaces filled with blood and separated by fibrous septa, alternating with solid areas Cysts and septa lined by fibroblasts, myofibroblasts and histiocytes but not endothelium Clusters of osteoclast-like multinucleated giant cells with loose spindly stroma to cellular stroma , reactive woven bone, degenerated calcifying fibromyxoid tissue Variable mitotic figures and hemosiderin No malignant osteoid, no atypia

82. RADIOLOGY : Eccentric expansion of bone, cortical erosion and destruction, small peripheral area of periosteal bone formation Fluid levels detectable by CT MRI shows honeycomb appearance with fluid levels

83. DIFFERENTIAL DIAGNOSIS Odontogenic cyst Haemangioma Giant cell granuloma Eosinophilic granuloma Myxoma Ameloblastoma Metastasis

84. TREATMENT : 25% recur after curettage so aggressive curettage with bone grafting or en bloc resection recommended

85. PARASITIC INFECTIOUS INFLAMMATORY NON ODONTOGENIC CYST Usually echinococcal , as part of disseminated hydatid disease Primary hydatid cyst of the adrenal gland is extremely rare Rarely caused by visceral leishmaniasis EPIDIMIOLOGY : Hydatid disease accounts for 6% - 7% of all adrenal cysts  CLINICAL FEATURES : Mostly asymptomatic, occasionally with abdominal pain

86. HISTOLOGY : Wall contains many eosinophils , also evidence of parasite

87. TREATMENT : Surgical excision Anthelmintic agents