Developmental Mucocutaneous Diseases

Question 1

what are the 4 Developmental Mucocutaneous Diseases discussed in this section?

Answer 1

1) Ectodermal dysplasia
2) White sponge nevus
3) Peutz-Jeghers syndrome
4) Hereditary hemorrhagic telangiectasia

Question 2

what is the most common, and well known, form of ectodermal dysplasia?

Answer 2

Hypohidrotic ectodermal dysplasia

Question 3

what is the definition for “ectodermal dysplasia”?

Answer 3

Group of inherited disorders in which:

two or more ectodermally derived structures do not develop normally or fail to develop

Question 4

what kinds of ectodermal structures can be effected by ectodermal dysplasia?

Answer 4

Skin, hair, nails, teeth or sweat glands

Question 5

T/F: For ectodermal dysplasia, there are Several patterns of inheritance depending on the type

Answer 5

True

there are over over 170 different subtypes, each with its own inheritance pattern

Question 6

what are the extra oral symptoms of Hypohidrotic E. D.?

Answer 6

Heat intolerance due to reduced sweat glands

Fine, sparse blonde hair, eyebrows, eyelashes

Question 7

what are the oral effects of Hypohidrotic Ectodermal Dysplasia?

Answer 7

Oligodontia (lack of development of 6 or more teeth)

conical teeth

Question 8

how is ectodermal dysplasia managed?

Answer 8

Genetic counseling

Prosthetic dental management – based on the specifics of the case

Question 9

what are the prosthetic dental options for Ectodermal Dysplasia?

Answer 9

Dentures
Overdentures
Fixed appliances
Dental implants

Question 10

what are the odds of 2 offspring both having Polygenetic Oligodontia?

Answer 10

1:100,000

Question 11

What is the inheritance pattern for White Spot Nevus?

Answer 11

Autosomal dominant

Question 12

White Sponge Nevus is a type of “_______________”, meaning its a genetically-determined skin disorder

Answer 12

genodermatosis

Question 13

when is white spot nevus usually diagnosed?

Answer 13

Usually first noticed at birth or in early childhood, sometimes noticed first in adolescence

Question 14

what defect causes white sponge nevus?

Answer 14

Due to a defect in the normal keratinization of the oral mucosa

keratins 4 and 13

Question 15

what are the oral findings for white spot nevus?

Answer 15

1) Asymptomatic, thick, white appearance of the buccal mucosa bilaterally
2) other oral sites may be affected as well
3) Nasal, esophageal, laryngeal, anogenital mucosa may also be involved

Question 16

When diagnosing White Spot Nevus, ______________ is sometimes more diagnostic than a biopsy sample

Answer 16

Exfoliative cytology

Question 17

what are the histological characteristics of White Spot Nevus?

Answer 17

A) Biopsy shows parakeratosis with acanthosis (thickening of the spinous layer)

B) Epithelial cells often show perinuclear eosinophilic condensation of cytoplasm; pathognomonic, or unique to WSN

Question 18

what is the treatment protocol for White Spot Nevus?

Answer 18

1) No treatment is necessary
2) Reassure the patient that this is a harmless condition
3) Good prognosis

Question 19

______________ syndrome is a relatively rare, but well recognized condition that is usually inherited as an autosomal dominant trait

Answer 19

Peutz-Jeghers Syndrome

Question 20

About ___% of Peutz-Jeghers syndrome may represent new mutations

Answer 20

35%

Question 21

what gene is mutated in Peutz-Jeghers syndrome?

what does this gene do?

Answer 21

SKT11 gene is affected – encodes for a serine/threonine kinase

Question 22

what is the prevalence of Peuzt-Jeghers syndrome?

Answer 22

about 1 in 100,000 – 200,000 births

Question 23

name the clinical characteristics of Peuzt-Jeghers syndrome:

Answer 23

A) Usually noticed in childhood

B) Characterized by freckle-like lesions which develop on the hands, periorificial skin (mouth, nose, anus, genital region) and oral mucosa

C) Polyps develop in the GI tract, especially the jejunum and ileum

Question 24

Peuzt-Jeghers syndrome can cause bowel obstruction due to _______________

Answer 24

intussusception
(“telescoping” of a proximal segment into a distal segment)

May self-correct but surgery is sometimes needed to prevent ischemic necrosis

Question 25

patients with Peutz-Jeghers Syndrome have an increased susceptibility to cancer that is about _____ times greater than a control population

Answer 25

18 times

Question 26

which forms of cancer are most common in Peutz-Jeghers syndrome?

Answer 26

GI, pancreas, male and female genital tract, breast and ovary

Question 27

Histopathology of the GI polyps due to Peutz-Jeghers syndrome:

Answer 27

Gastrointestinal polyps appear as benign hamartomatous (tissues normally present in the affected part) growths of intestinal glandular epithelium

these are NOT precancerous (that would be gardeners syndrome)

Question 28

what is the treatment protocol for Peutz-Jeghers?

Answer 28

Genetic counseling

Patients should be monitored for intussusception and for tumor development

Question 29

what is the inheritance pattern for Hereditary Hemorrhagic Telangiectasia? how prevalent is the disease?

Answer 29

autosomal dominant disorder that is estimated to have a frequency of about 1 in 10,000

Question 30

Hereditary Hemorrhagic Telangiectasia is caused by a mutation of what?

Answer 30

Due mutation of one of 2 different genes, both of which play a role in blood vessel wall integrity and share similar clinical features

Question 31

____________ are small collections of dilated capillaries

Answer 31

Telangiectasias

Question 32

what are the clinical characteristics of HHT?

Hereditary Hemorrhagic Telangiectasia

Answer 32

A) Frequent spontaneous epistaxis often is the initial clue to the diagnosis

B) Numerous 1-2 mm red papules that blanch with diascopy are noted on the oropharyngeal and nasal mucosae

Question 33

where are Hereditary Hemorrhagic Telangiectasia lesions most often found?

Answer 33

Lesions are most common on vermilion zone of lips, tongue and buccal mucosa

Question 34

T/F: HHT may involve the GI mucosa, genitourinary mucosa, and conjunctival mucosa

Answer 34

true

Question 35

What % of Hereditary Hemorrhagic Telangiectasia patients have Atriovenous fistulas in their lungs? Liver? Brain?

Answer 35

lungs (30% of patients)

liver (30%)

brain (10-20%)

Question 36

the diagnosis for Hereditary Hemorrhagic Telangiectasia depends on what 4 features?

Answer 36

Diagnosis can be made if patient has 3 of 4 features:

1) Recurrent spontaneous epistaxis
2) Telangiectasias of mucosa and skin
3) AV malformation involving the lung, liver or brain
4) Family history of HHT

Question 37

what are the histopathological features of HHT?

Answer 37

Collection of thin-walled blood vessels in the superficial connective tissue

Question 38

what is the general treatment protocol for Hereditary Hemorrhagic Telangiectasia?

(give for mild, moderate & severe)

Answer 38

Genetic counseling

Mild HHT – no treatment

Moderate HHT – selective cryotherapy or electrocautery of bothersome lesions

Severe – septal dermoplasty to prevent epistaxis

Question 39

what component of Hereditary Hemorrhagic Telangiectasia would warrant the use of prophylactic antibiotics?

Answer 39

With AV fistula involving brain, prophylactic antibiotics before dental procedures that cause bacteremia have been suggested due to 1% prevalence of brain abscess in these patients

Question 40

prognosis for Hereditary Hemorrhagic Telangiectasia:

Answer 40

Generally good, although 1-2% mortality is sometimes noted due to complications related to blood loss

If brain abscess develops, then 10% mortality can be anticipated, despite early diagnosis and appropriate treatment