Radiolucent Non-Odontogenic Lesions

Question 1

Nasolabial Cyst

Answer 1

RL Non-Odontogenic Cyst

• Developmental cyst
• Develops from remnants of nasolacrimal duct
• Upper lip, lateral to midline
• Nasal/MX processes
• More common in females 2:1
• Elevation of ala of the nose
• Swelling of lip lateral to mimdline
• Characteristically lined by pseudostratified columnar epithelium, often w/ Goblet cells & cilia

Question 2

Nasolabial Cyst: Tx

Answer 2

RL Non-Odontogenic Cyst

Surgical excision

Recurrence is rare

Question 3

Another name for Nasopalatine Duct Cyst

Answer 3

RL Non-Odontogenic Cyst

Incisive canal cyst

Question 4

What is the most common non-odontogenic cyst?

Answer 4

RL Non-Odontogenic Cyst

Nasopalatine Duct Cyst

Question 5

Nasopalatine Duct Cyst

Answer 5

RL Non-Odontogenic Cyst

• Most common non-odontogenic cyst
• Connects oral and nasal cavities in the incisive canal area
• Swelling of anterior palate, w/ drainage and pain
• Most common in 4th-6th decades of life

Question 6

Nasopalatine Duct Cyst: Rad

Answer 6

RL Non-Odontogenic Cyst

• RL
• Well-circumscribed
• Round/oval
• Inverted pear
• Heart shape
• Lined by highly variable epithelium (75% stratified squamous)

Question 7

Nasopalatine Duct Cyst: Tx

Answer 7

RL Non-Odontogenic Cyst

• Surgical excision
• Biopsy req’d
• Lesions not dx radiographically
• Other lesions can mimic this one
• Recurrence is rare

Question 8

Globulomaxillary Cyst

Answer 8

RL Non-Odontogenic Cyst

• Fusion of globular and MX processes
• B/w incisor & K9
• THIS CYST DOESN’T EXIST

Question 9

Median MN Cyst

Answer 9

RL Non-Odontogenic Cyst

• Fusion of halves of MN during embryonic life
• Most of these midline cysts are odontogenic in origin
• THIS CYST DOESN’T EXIST

Question 10

Idiopathic Bone Cavity

Answer 10

RL Non-Odontogenic Pseudocyst

• AKA Simple Bone Cyst
• Cavity usually filled w/ blood but not a real cyst b/c no epithelial lining; thinly corticated
• Cause & pathogenesis are uncertain
• In younger people (10-20yo) and not always from trauma
• 90% in posterior MN
• MOST OF THE TIME cavity has some mixture of blood and other fluids; otherwise filled w/ air
  
  • 65%: Sero-sanguinolent fluid
  • 35%: Empty bone cavity
• Key: NO EPITHELIAL LINING = NOT A CYST

Question 11

Idiopathic Bone Cavity: Rad

Answer 11

RL Non-Odontogenic Pseudocyst

• Well-defined RL, thinly corticated superior border and non-corticated inferior border
• Interdental scalloping: Classic feature of SBC/IBC

Question 12

Idiopathic Bone Cavity: Tx

Answer 12

RL Non-Odontogenic Pseudocyst

• Dx based on clinical, rad, surgical features
• After surgical exploration, heals in 6mo
  
  • Open up and find it’s just filled w/ blood so close up and it will heal
• Good px

Question 13

Stafne Bone Cyst

Answer 13

RL Non-Odontogenic Pseudocyst

• Focal concavity of bone on lingual surface of MN; associated w/ subMN gland
  
  • Defect from extra subMN gland tissue
• Rarely found in upper MN ramus and anterior MN
• Striking male predilection: 90% of cases in males
• RL below MN canal; b/w molar teeth and angle of MN

Question 14

Another name for Idiopathic Bone Cavity

Answer 14

Simple Bone Cyst

Question 15

Another name for Stafne Bone Cyst

Answer 15

Stafne Bone Defect

Static Bone Cyst

Question 16

Stafne Bone Cyst: Rad

Answer 16

RL Non-Odontogenic Pseudocyst

• Usually has thick corticated borders
• RL below MN canal; b/w molars and angle of MN

Question 17

Stafne Bone Cyst: Tx

Answer 17

RL Non-Odontogenic Pseudocyst

• No tx needed
• Excellent px
• Lesions in anterior jaws may be difficult to recognize
• Biopsy may be needed to r/o other pathologic lesions

Question 18

Central Giant Cell Granuloma

Answer 18

RL Non-Odontogenic Lesions: Other

• More common in children & young adults but can occur in all ages
• More common in MN, but can also occur in MX
• Benign, but aggressive lesions can grow rapidly
• More in women; <30yo
• Classically found in anterior MN

Question 19

Aggressive CGCG vs. Non-Aggressive CGCG

Answer 19

RL Non-Odontogenic Lesions: Other

• Most CGCG lesions are NON-AGGRESSIVE
  
  • Asymptomatic, slowly growing, no root resorption, no perforation of cortical bone
  • Tend not to recur after curettage
• AGGRESSIVE CGCG
  
  • Pain or paresthesia, root resorption, cortical perforation
  • Higher recurrence rate after curettage
  • Still benign looking even though it’s aggressive

Question 20

CGCG: Rad

Answer 20

RL Non-Odontogenic Lesions: Other

• RL lesions w/ well-defined borders, similar to odontogenic tumors & cysts
• May or may not have corticated border
• Unilocular or multilocular, depending on size
• Can cause expansion and/or perforation of cortical plate
• Tends to resorb roots horizontally

Question 21

CGCG: Microscopic features

Answer 21

RL Non-Odontogenic Lesions: Other

• Fibrous tissue, numerous multinucleated giant cells, hemorrhage, hemosiderin
• Resembles hyperparathyroidism & cherubism

Question 22

What pathogolies does CGCG resemble?

Answer 22

RL Non-Odontogenic Lesions: Other

• Hyperparathyroidism
  
  • ​Increased serume PTH levels
• Cherubism
  
  • <10yo, bilateral

Question 23

CGCG: Tx

Answer 23

RL Non-Odontogenic Lesions: Other

• Usually curettage is used (15-20% recurrence rate)
• Aggressive lesions: Intralesional corticosteroids, calcitonin, interferon

Question 24

Hemangioma/Vascular malformation

Answer 24

RL Non-Odontogenic Lesions: Other

• Hemangioma: Benign proliferation of small BVs
• Vascular malformation: AKA arteriovenous malformation and high flow angioma
  
  • Proliferation of small BVs and larger arterial vessels associated w/ more blood flow and can result in excessive bleeding during surgery
  • Part of Sturge-Weber Syndrome
• Usually detected during first 3 decades of life
• Vaslcular malformations may have thrill (pulsatile to palpation) or bruit (heard upon auscultation)

Question 25

Hemangioma/Vascular malformation: Rad

Answer 25

RL Non-Odontogenic Lesions: Other * RL lesions w/ well-defined, corticated borders * Usually RL, but may have RO areas and/or multilocular "honeycombed" or "soap bubble" appearance * May have coarse internal trabeculae * Aspiration of all bony lesions is done before biopsy or tooth extraction to r/o vascular malformations

Question 26

Hemangioma/Vascular malformations: Tx

Answer 26

RL Non-Odontogenic Lesions: Other * **Angiography** * **Surgical resection** * Thromboembolization of vascular malformations may be req'd before surgery

Question 27

Focal Osteoporotic Bone Marrow Defect

Answer 27

RL Non-Odontogenic Lesions: Other * Area of hematopoietic marrow that produces RL * May be confused w/ an intraosseous neoplasm * **Variation of normal** * Typically asymptomatic * No jaw expansion * Not completely RL so can't be a cyst * 75% in women; typically posterior MN

Question 28

Focal Osteoporotic Bone Marrow Defect: Rad

Answer 28

RL Non-Odontogenic Lesions: Other * **Key: Differentiate from other lesions** * **​Irregular shape** * **Trabecular pattern still seen inside the lesion** * No jaw expansion * Not completely RL so can't be a cyst * Just widened trabecular spaces, not multilocular

Question 29

What are Radiolucent Non-Odontogenic Lesions?

Answer 29

* Nasolabial Cyst * Nasopalatine Duct Cyst * Globulomaxillary Cyst \*\*\* * Median MN Cyst \*\*\*

Question 30

What are RL Non-Odontogenic Pseudocysts?

Answer 30

* Idiopathic Bone Cavity * Stafne Bone Cyst

Question 31

What are Other RL Non-Odontogenic Lesions?

Answer 31

* Central Giant Cell Granuloma * Hemangioma/Vascular Malformation * Focal Osteoporotic Bone Marrow Defect