Key Items Quiz 3

Question 1

Tuberous sclerosis

Answer 1

Characterized by: CNS manifestation, Mental retardation, Seizure disorders, Potato-like growths (“tubers”), Angiofibromas of the skin, Ungual (or periungual) fibromas, characteristic skin lesions-Shagreen patches and Ash-leaf spots (ovoid area of hypopigmentation)

Question 2

What is this

Answer 2

Odontoma

Most common odontogenic tumor

developmental anomalies (hamartomas) rather than true neoplasms

2 types: compound or complex

average age=15

Relatively small and discovered via XRAY when films are taken to determine the reason for failure of tooth eruption

Compound is more common in anterior maxilla; complex is more common in the molar regions

Compound-collection of tooth like stuctures varying in size and shape, surrouned by RL zone

Complex-calcified mass with RL similar to teeth, surrounded by RL rim

Question 3

What is this

Answer 3

Amelobalstoma

Most common clinically significant odontogenic tumor

3 different types: Conventional solid or multicystic – 85%, Unicystic – 15%, Peripheral – 1%

Equal prevalence in the 3rd-7th decade

85% occur in the mandible, usually the molar-ascending ramus area – board question

If untreated, can grow to grotesque proportions – even then, pain & paresthesia are uncommon

typical radiographic feature is a multilocular radiolucency- “soap bubble” if large, “honeycombed” if small

buccal and lingual expansion is frequently present

root resorption is common

Desmoplastic form-predilection for anterior maxilla, RL-RO

Palisading and reverse polarity

Take 1.5cm margins beyond radiographic location

Question 4

Polyostotic fibrous dysplasia

Answer 4

Jaffe-Lichenstien: polyostotic fibrous dysplasia and cafe au lait (coast of maine)

McCune-Albright: polyostotic fibrous dysplasia, cafe au lait (coast of maine), and multiple endocrinopathies (sexual percosity), pituitary adenoma and/or hyperthyroidism

Sexual percosity=early onset puberty

Question 5

Aneurysmal bone cyst

Answer 5

Intraosseous accumulation of blood-filled spaces surrounded by connective tissue

NOT a true cyst; no epithelial lining

swelling that has developed rapidly

Pain is often reported

X-Ray: RL, coritcal expansion and thinning, usually unilocular but could be multilocular

during surgery “blood soaked sponge”

Question 6

Schwannoma

Answer 6

aka Neurilemoma

benign neural neoplasm of of Schwann cell origin

50% of cases in H&N

Bilateral schwannomas of auditory-vestibular nerve are a characteristic feature of the neurofibromatosis type II (NF2)

tongue is the most common location for oral lesions

Antoni-A, organized, verocay bodies

Antoni-B, disorganized

Question 7

Multiple Endocrine Neoplasia Type 2B (MEN 2B)

Answer 7

Charcterized by tumors of endocrine origin: parathyroid, pituitary, pancrease, adrenal gland (pheochromocytosis, 50%), thryoid (medullary carcinoma, 90%), mucosal neuromas

Marfanoid build

Oral mucosal neuromas are typically the first sign of the condition

Bilateral neuromas of the commissural mucosa are highly characteristic

Marked propensity for metastasis

Diagnosed between 18-25

Question 8

Peutz-Jeghers syndrome

Answer 8

Rare but well recognized

Characterized by: Freckle-like lesions of the hands, perioral skin, and oral mucosa, Intestinal polyposis, Predisposition for affected patients to develop cancer

Skin lesions develop in childhood and involve periorificial areas-Lesions resemble freckles, but do not wax and wane with sun exposure

Intestinal polyps are hamartomatous growths-NOT PREMALIGNANT

Intestinal obstruction due to intussusception

about 18x more likely to have a malignancy in their lifetime

GI adenocarcinoma also develops (but not from the polys)

Question 9

Anemia

Answer 9

a decrease in volume of RBCs or in the concentration of hemoglobin

General symptoms: Tiredness, headache, fainting/feeling light headed, and pallor

Oral symptoms include: bald tongue (tongue atrophy), burning tongue (glossopyrosis), pain in the tongue (glossodynia)

Question 10

Rhabdomyoma

Answer 10

Benign tumor of skeletal muscle

Extracardiac rhabdomyomas are very rare but have a predilection for the H&N

Adult and fetal types

70% of adult type are in men, nodular mass occuring in the pharynx or the floor of the mouth

Question 11

Lymphoid hyperplasia

Answer 11

Enlargement of lymphoid tissue

May effect lymph nodes or Waldeyers’ ring

Common sites of lymph tissue in the oral cavity: oropharynx, soft palate, lateral tongue and floor of the mouth

Question 12

Nevoid basal cell carcinoma syndrome

(Gorlin syndrome)

Answer 12

Chromosome 9 (PTCH gene)

Characterized by: Multiple basal cell carcinomas, OKCs, Calcification of falx cerebri, Bifid ribs

BCCAs appear around puberty and on skin not exposed to sunlight

OKCs are the most common feature-frequently multiple

Prognosis depends on skin tumors

Question 13

Answer 13

Langerhans cell histiocytosis

Punched out radiolucency

teeth floating in air

Question 14

Erythema Multiforme

Answer 14

Blistering, ulcerative mucocutaneous condition of uncertain etiopathogenesis

In 50% of cases, the clinician can identify a preceding infection or exposure to a medication

Infection is usually herpes simplex or Mycoplasma pneumoniae; medications are usually antibiotics or analgesics

spectrum=EM (minor), EM (major-steven-johnson’s syndrome), toxic epidermal necrolysis (lyell’s disease)

Acute onset

Prodromal symptoms (fever, headache, cough, sore throat) occur 1 week before onset

A highly characteristic skin lesion that develops is a target lesion

Hemorrhagic crusting of the vermilion zone of the lips is common

Steven-Johnson’s syndrome-usually triggered bu drug- To make this diagnosis, there must be skin, oral mucosa, and either ocular or genital mucosa involvement

Question 15

Ossfying fibroma

Answer 15

True neoplasm with significant growth potential

composed of fibrous tissue that contains a variable mixture of bone & cementum

painless swelling

X-Ray: well defined, unilocular, mixed RL-RO, root divergence or resorption can occur

Large ossifying fibromas of the mandible demonstrate a characteristic downward bowing of the inferior cortex of the mandible

do not undergo malignant transformation

recurrence-rare

F>M

Question 16

Gigantism/Acromegaly

Answer 16

Increased production of growth hormone, usually related to a functioning pituitary adenoma

Gigantism occurs before closure of epiphyseal plates, oral finding=macrodontia

Acromegaly, after closure of epiphyseal plates, Increased growth of mandible (prognathism) with diastema formation, macroglossia

Question 17

Amyloidosis

Answer 17

deposition of extracellular amyloid

Organ limited-Rarely seen in the oral cavity, Amyloid nudule

Systemic-Primary and myeloma associated

20% are due to multiple myeloma, macroglossia, commonly affect eyelid, neck and lips

Systemic-secondary

Chronic inflammatory response

Systemic-hemodialysis associated

Protein isn’t removed in dialysis so it accumulates in plasma, eventually deposites in bone and joints

Question 18

Metastasis to the oral soft tissues

Answer 18

One possible explanation of H&N mets in the absence of lung mets is Batson’s plexus

This is a valveless vertebral venous plexus that might allow retrograde spread of tumor cells & bypass the lungs

Gingiva is the most common site for soft tissue

Usually carcinomas not sarcomas

2/3s of METs go to soft tissue and 1/3 to bone

Question 19

Vitamin deficiencies

Answer 19

Vitamin A-Retinol-may lead to blindness

Vitamin B1-Thiamin-proper functioning of neurons-beriberi

Vitamin B2-riboflavin-cellular redox reactions-angular cheilitis and glossitis

Vitamin B3-Niacin-Pellagra=dermatitis, dimentia, diarrhea

Vitamin B6-prydoxine

Vitamin C-ascorbic acid-synthesis of collagen-scurvy

Vitamin D-hormone-calcium absorption-rickets and osteomalacia

Vitamin E-alpha tocopherol-antioxidant

Vitamin K-clotting-2,7,9,10-Coagulopathy because of inadequate synthesis of prothrombin

Question 20

Calcifying Odontogenic Cyst (COC)

Answer 20

Gorlin cyst

calcifying cystic odontogenic tumor

65% are found in the incisor-canine areas; mx=md

X-Ray: Unilocular, well-defined radiolucency, Radiopaque structures are seen within the RL in 50%

Question 21

Plummer-Vinson syndrome

Answer 21

Characterized by: iron-deficiency anemia, glossitis, and dysphagia

associated with a high frequency of both oral and esophageal squamous cell carcinoma

considered a premalignant condition

angular cheilitis often present

Spoon shaped configuration of nails (koilonchia)

5 to 50% chance of developing an upper aerodigestive tract malignancy

Question 22

Lateral peiodontal cyst

Answer 22

Intrabony counterpart of the gingival cyst of the adult

Striking predilection to occur in the mandibular premolar-canine-lateral incisor area

X-Ray: well-circumscribed RL, could be polycystic (called botryoid odontogenic cyst)

Question 23

CREST syndrome

Answer 23

C-calcinosis cutis

R-raynaud’s phenomenon

E-esophagal dysfuntion

S-Sclerodactyly

T-Telangiectasia

Question 24

Osteoid Osteoma

Answer 24

Pain is nocturnal and relieved by aspirin

Usually less than 1 cm

remember, less than 2 cm still indicates lesion is OO

Small RO nidus may be present, resulting in a “target-like” appearance

Question 25

Gingival cyst of the adult

Answer 25

**Soft tissue counterpart of the lateral periodontal cyst** derived from the rests of the dental lamina (rests of series) Striking predilection to occur in the mandibular canine & premolar area (75% of the time)

Question 26

Thrombocytopenia

Answer 26

Decreased number of circulating platelets resulting in abnormal bleeding Causes: decreased production, increased destruction, and sequestration in the spleen Could be caused by bone marrow malignancies or chemo Part of **SLE** or HIV Might be caused by thromboitc thrombocytopenic purpura (**TTP**) Normal levels 200,000-400,000 Symptoms when levels are below 100,000 **Petechiae**=small pinpoint hemorrhage Oral problems-spontaneous gingival hemorrhage and bleeding from minor site of trauma

Question 27

Osteopetrosis

Answer 27

Marble bone disease hardening of the bone marked increase in bone density defect in remodeling caused by a failure of normal osteoclast function 2 types: **infantile and adult** infantile=**malignant osteopetrosis**, wide spread increase in skeletal density Adult=**benign osteopetrosis** You see **osteonecrosis** because the bone grows and blocks blood flow Could be seen as part of **osteogenesis imperfecta**

Question 28

Answer 28

Central Giant Cell Granuloma Non-neoplastic lesion **More common in the anterior jaw and frequenly cross the midline** Multi or unilocular well delineated non corticated margin Histopathology is identical to brown tumor of hyperparathyroidism (must be evlauated) and lesions of **cherubism** 20% recurrence no risk for metastasis

Question 29

Hemangioma

Answer 29

Most common tumor of infancy 2 types: capillary and cavernous Capillary: may not blanch clinically, usually red Cavernous: typically blanches, darker red to purple

Question 30

Cemento-osseous dysplasia

Answer 30

Occurs in **tooth** **bearing** **areas** of the jaw **most common fibro-osseous lesion** encountered in clinical practice 3 types: focal, periapical, and florid For periapical- or florid cemento-osseous dysplasia, diagnosis can be made from the distinctive clinical & XRAY findings – do NOT need biopsy

Question 31

Multiple myeloma

Answer 31

Malignancy of **plasma** **cell** origin Multicentric origin within bone **Second to metastatic malignancies, this is the most common** **malignancy of the bone** Most common hematologic malignancy of African Americans X-Ray features: multiple "**punched out radiolucencies**" Renal issues can be a sign because of the high volume of proteins in the blood called **bence jones protiens**

Question 32

Cherubism

Answer 32

Developmental jaw condition Cherublike faces arises from **bilateral** **involvement** of the posterior mandible that produces chubby cheeks There is an “eyes upturned to heaven” appearance due to a wide rim of exposed sclera noted below the iris Occurs between the ages of **2-5** Clinical alterations progress until puberty and then stabilize and slowly regress **Bilateral CGCGs, posterior and expansile** Widening and expansion of alveolar ridges X-Ray: multilucular, expansile, radiolucent

Question 33

Systemic sclerosis

Answer 33

A disease in which **dense collagen is deposited** in the tissues First sign of disease is **Raynaud’s phenomenon**-Vasoconstrictive event triggered by emotional distress or exposure to cold Common cause of **death is pulmonary fibrosis** causing pulmonary hypertension and heart failure **Microstomia** occurs as a result of collagen deposition in the perioral tissues **Xerostomia** is frequently encountered Dental appliances are used to combat microstomia

Question 34

What are 2 types of neuromas?

Answer 34

Traumatic and palisaded encapsulated neruoma

Question 35

Lupus Erythematous

Answer 35

**Immunologically** mediated **Most common collagen vascular or connective tissue disease in the US** several types but know these 2-Systemic lupus erythematous, Chronic cutaneous lupus erythematous **SLE**-Malar rash-50% **Kidney problems** (most significant issue) Cardiac problems (pericarditis)- Up to 50% have warty vegetations affecting heart valves termed Libman-Sacks endocarditis Oral lesions are lichenoid lesions Treatment with **antimalarial** drugs (hydroxychloroquine) Most common cause of death is kidney failure

Question 36

Answer 36

Idiopathic osteosclerosis Increased radiodensity Don't confuse with focal cemento-osseous dysplasia-radioluncent rim Don't confuse with cementoblastoma-fused with the tooth 90% in mandible

Question 37

Hodgkin's lymphoma

Answer 37

**Malignant lymphoproliferative disorder** Neoplastic cells are called **Reed-Sternberg** cells (**1-3% of cell of the lesion**) Binucleated "**owl eye"** Significant percentage linked to **EBV** 75% occur in the **cervical and supraclavicular nodes**

Question 38

Eruption cyst

Answer 38

Soft tissue analogue of the dentigerous cyst Occurs within the soft tissues overlying the alveolar bone Usually seen in children younger than 10 blue or purple color

Question 39

Iron deficieny anemia

Answer 39

**Most common cause of anemia** develops from **excessive blood loss** oral manifestations-**angular cheilitis and atrophic glossitis** Microcytic

Question 40

Gardner sydrome

Answer 40

Think of **osteoma** **Colonic** **polyps**/adenocarcinomas Skeletal abnormalities Dental abnormalities Epidermoid cyst Bowel polyps develp during teenage years, **WILL** transform into adenocarcinomas (50% by 30, 100% later in life) Skeletal abnormalities-osteomas are most common, precede bowel polyps Dental abnormalities-**supernumerary,** impacted teeth, and odontoma

Question 41

Leukemia

Answer 41

**malignancies of hematopoietic stem cell derivation** malignant transformation of a hematopoietic stem call that invades the bone marrow and over flows into the periphral blood **Chonic/acute and myeloid/lymphoid** **Acute** can lead to **death** in a few months if not treated CML-translocation of long arms of 9 & 22 (philadelphia choromosome) Viruses-HTLV-1 **ALL** common in **childhood** CLL most common in adults If leukemic cells enter the oral cavity they can cause a "**boggy**" non tender swelling historically called a granulocytic sarcoma

Question 42

Rhabdomyosarcoma

Answer 42

Malignancy of skeletal muslces 60% of soft tissue sarcomas in childhood Painless, infiltrative mass that grows rapidly

Question 43

Traumatic bone cyst

Answer 43

Simple bone cyst Benign empty of fluid filled cavity in the bone "Cyst” is a misnomer because the lesion does not have an epithelial lining Trauma causes an intraosseous hematoma, doesn't repair properly Majority are found in long bones 10-20 years old almost **exclussively in mandible** When several teeth are involved, the defect shows domelike projections that **scallop** between the roots; this feature is highly suggestive Teeth are **vital**

Question 44

Juvenile (active) ossifying fibroma

Answer 44

**M\>F** (opposite of **ossifying** **fibroma**) **Psammomatoid:trabecular** 4:1 RL with central RO MX\>MD **recurrence** **30-60%** no malignant transformation

Question 45

Osteoblastoma

Answer 45

md\>mx posterior\>anterior between **2-4 cm** Pain, tenderness, and swelling are important and common presenting features (but not relieved by aspirin) **RL with varying degrees of central RO**

Question 46

Florid cemento-osseous dysplasia

Answer 46

Multiple focal involvement not limited to the anterior mandible **90% are female; 90% are African American** Marked tendency to be **bilateral** and **symmetrical** X-Ray features are similar to other 2, RL rim

Question 47

Paget's disease of bone

Answer 47

Abnormal resorption and deposition of bone results in distortion and weakening of affected bones **Polyostotic** CC: **bone pain** Pagetic bone forms near joints, promotes osteoarthritic changes Weight bearing bones get a bowing deformity if skull is affected, it leads to an increase in the circumference of the head (**hat no longer fits**) Maxillary more common than mandibular **Enlargement of middle 1/3 of face**, resulting in leontiasis ossea (lion like face) X-Ray: patchy sclerotic areas (**cotton wool or cotton roll** appearance, **hypercementosis**, Have **elevated serum alkaline phosphatase** levels, with **normal calcium and phosphorus levels** Can develop malignant bone tumor osteosarcoma

Question 48

Cleidocranial dysplasia

Answer 48

Dental and clavicle abnormalities Increased prevalence of cleft palate prolonged retention of deciduous teeth delayed or failure of eruption of permanent teeth **Numerous unerupted permanent and supernumerary teeth**

Question 49

Periapical cemento-osseous dysplasia

Answer 49

Periapical regions of anterior mandible **90% female, 70% African Americans** early lesions look like periapical cyst or granuloma, with time the turn mixed RL-RO, and then densly RO with RL rim PDL will be intact, will not fuse to tooth

Question 50

Focal cemento-osseous dysplasia

Answer 50

90% occur in females average age 40 On boards more common in caucasians Posterior mandible X-Ray: RL to densly radiopaque, **thin RL rim**, mixed RL-RO, well defined

Question 51

Cementoblastoma

Answer 51

Odontogenic neoplasm of cementoblasts **75% arise in the mandible, almost always in the molar/premolar region** X-Ray: RO mass that is **fused** to one or more tooth roots, **outline of the root or roots is usually obscured**, surrounded by a thin **RL rim**

Question 52

Fibrous dysplasia

Answer 52

Tumor like condition **replacement of normal bone with fibrous CT intermixed with bone** Results from a **postzygotic mutation** could be mono or polyostotic

Question 53

Mono-ostotic fibrous dysplasia

Answer 53

80% of all cases Maxilla \> mandible X-Ray: ground glass opacification (poorly calcified bone in disorganized fashion) Not well demarcated

Question 54

Dentigerous cyst

Answer 54

3mm or less is normal area surrounding an erupting tooth Unerupted tooth fluid between the reduced enamel epithelium and the tooth crown Most common developmental cyst Encloses the crown of the unerupted tooth and is attached at the CEJ Most often involve mandibular 3rd molars X-Ray: Unilocular radiolucency associated with crown of unerupted tooth, Well-defined and usually sclerotic border

Question 55

Calcifying Epithelial Odontogenic Tumor (CEOT)

Answer 55

AKA **Pindborg** **Tumor** MD\>MX posterior\>anterior Most common presenting sign is a painless, slow-growing swelling X-Ray: uni (more common in maxilla) or multilocular, Margins are typically scalloped & well-defined, Frequently associated with an impacted tooth, **driven-snow** **Amyloid**-like extracellular material; positive for **Congo red**, which exhibits an **apple-green** Calcifications with concentric rings form in the amyloid-like areas (**Liesegang rings**)

Question 56

Metastatic tumors to the jaw

Answer 56

Most common origin of gnathic mets: **Breast**, **lung**, thyroid, prostate, kidney Older patients 80% of jaw mets occur in the mandible If close to the IA it can produce numb-chin syndrome Can be discovered in non-healing EXT sites X-Ray: ill defined boarder "**moth eaten**"

Question 57

Ectodermal dysplasia

Answer 57

Group of inherited conditions in which two or more ectodermal derived anatomic structures fail to develop: **Skin**, **hair**, **nails**, **teeth**, **sweat** **glands** Best known is **hypohidrotic** ectodermal dysplasia X-linked **Periocular** **wrinkling** with **hyperpigmentation** **Hypoplastic** or **absent** salivary glands Teeth are markedly reduced in number and have abnormal crown shapes (**conical**)

Question 58

Buccal bifurcation cyst

Answer 58

Characteristically develops on the buccal aspect of the **mandibular** **first** **permanent** **molar** **1/3** have **bilateral** involvement X-Ray: Well-circumscribed, unilocular radiolucency involving the buccal bifurcation and root, An occlusal XRAY can demonstrate buccal location, The root apices are characteristically tipped toward the lingual mandibular cortex Treated by enucleation

Question 59

Focal osteoporotic marrow defecy

Answer 59

Area of **hematopoetic marrow** that produces a radiolucency may be confused with an intraosseous neoplasm NOT pathology ill defined boarder with fine **central trabeculations** posterior mandible

Question 60

Pernicious anemia

Answer 60

**Megaloblastic** anemia caused by **poor absorption of cobalamin** (vitamin B12 extrinsic factor) lack intrinsic factor because of autoimmune destruction of the parietal cells of the stomach, which results in decreased absorption of cobalamin **atrophic glossitis**

Question 61

Mucous Membrane Pemphigoid

Answer 61

aka cicatricial pemphigoid **Twice** **as** **common** as pemphigus Average age=55 Intraoral blisters may be seen clinically (unlike with pemphigus); an intraoral blood blister is virtually pathognomonic **Most significant complication is the ocular involvement**- Adhesions, called **symblepharons**, result, Scarring can turn the eyelids inward (entropion), which causes the eyelashes to rub against the cornea

Question 62

Langerhan's cell histiocytosis

Answer 62

dendritic mononuclear cells-epidermis, lymph nodes, mucosa and bone marrow **antigen presenting cells** more than 50% of patients are younger than 15 years old **Birbeck granules** differentiate these from other APCs Radiographically-"**punched out radiolucencies**", teeth look like they are "**floaiting in air**"

Question 63

Osteosarcoma

Answer 63

Mesenchymal malignancy ability to produce osteoid or immature bone **Excluding hematopoietic neoplasm**s, it is the **most common type of malignancy to originate within bone** intramedullary, juxtacortical, or extraskeletal extragnathic, bimodal age distribution: **10-20** (more common) and after **50** Osteosarcomas of the jaws comprise 7% of all osteosarcomas, around age 33 X-Ray:May be RO, RO with RL border, mixed, or RL, peripheral border is ill-defined, **Root resorption** can occur; which is termed **spiking resorption** – tapered narrowing of root, **Classic is sunburst appearance – found only in 25% and due to bony projections on the surface of the lesion,** A triangular elevation of periosteum termed **Codman’s triangle** can occur, Widened PDL around multiple teeth

Question 64

Pemphigus Vulgaris

Answer 64

4 diseases but vulgaris (most common) is the one that affects the mouth oral lesions are the "**first to show and last to go**" Autoantibodies are directed to desmosomes without treatment, oral and cutaneous lesions are progressive characteristic feature is a **positive Nikolsky sign**: Bulla can be induced on normal-appearing skin if firm lateral pressure is exerted Tzank cells (similar to herpes) Direct immunofluorescence show postive C3 and IgG Hailey-Hailey disease-Familial pemphigus

Question 65

Changes in tonsils during acute and chronic infections

Answer 65

Acute-enlarged, tender, soft and freely movable Chronic-enlarged, firm, non-tender, freely movable hard to distinguish from lymphomas Lymphoid tissue is usually more prominent in younger patients; peaking around age 20, then decreasing in size Tonsillar asymmetry is a potentially serious sign that should be further evaluated to rule out a metastatic tumor or lymphoma

Question 66

What is the difference between osteoblastoma and osteoid osteoma?

Answer 66

Osteoid osteoma produces prostaglandins (cause pain); the pain is relieved by aspirin (Enough prostaglandins to cause pain but enough the aspirin works, once it gets bigger the aspirin doesn’t help) Distinction usually depends on the size of the lesion; osteoid osteomas are SMALLER than 2 cm; osteoblastomas are larger

Question 67

Adenomatoid Odontogenic Tumor (AOT)

Answer 67

**Young** **patients** 10-20 **uncommon** **over age of 30** striking predilection for **anterior** **jaws** MX\>MD F:M, 2:1 Asymptomatic and discovered during XRAY to determine why a tooth hasn’t erupted **In 75% of cases, the tumor is a circumscribed, unilocular RL involving the crown of an unerupted tooth** RL often extends apically **past the CEJ**; this can help differentiate from dentigerous cyst fine, **snowflake calcifications** via XRAY

Question 68

Odontogenic Keratocyst (OKC)

Answer 68

2 most important things: **30% recurrence rate**, **associated with a syndrome** (Gorlin syndrome) Arise from cell rests of the dental lamina AKA keratocystic odontogenic tumor (KOT) Posterior mandible **Tend to grow in an anterior-posterior direction** X-Ray: smaller lesions-unilocular RL with corticated margins, large lesions-multilocular **unerupted** tooth is involved in 1/3 of cases Thin friable wall, epithelial cells **6-8 layers thick, palisading**, hyperchromatic, parakeratin **daughter cysts** (high recurrence rate)

Question 69

Leiomyoma

Answer 69

Benign tumor of smooth muscle Most oral lesions are a vascular variant (**angioleiomyoma**)

Question 70

2 special types of thrombocytopenia

Answer 70

ITP (immune thrombocytopenic purpura)-childhood following viral infection TPP (thrombotic throbocytopenic purpura)-serious disorder of coagulation and is probably due to endothelial damage

Question 71

Lichen Planus

Answer 71

Skin lesions are the **4** **Ps**: Purple, Pruritus, Polygonal, Papules (Wickham's striae) 2 oral forms: **reticular** (more common) and **erosive** Reticular-**Wickham's striae** Erosive-Lesions are atrophic, erythematous areas with a central ulceration If confined to gingiva it is called **desquamative gingivitis** Histo: "saw tooth rete ridges", **band like infiltrate of lymphocytes** subjacent to epithelium

Question 72

White sponge nevus

Answer 72

Defect in **keratins** (keratins **4**, **13**) Lesions appear at **birth** or in **early childhood** Symmetrical, thickened, white, corrugated, **diffuse plaques on the bilateral buccal mucosa** **Benign** condition with no treatment

Question 73

Osteoma

Answer 73

**Benign tumor of mature bone** restricted to **craniofacial skeleton** paranasal sinus lesions are more common than gnathic X-ray: **circumscribed masses** exhibit continued growth if compact bone RO: if cancellous mixed RO-RL Completely benign with extremely rare recurrence