Ameloblastoma (Odontogenic Tumor) Oral Pathology

transcript

AMELOBLASTOMA

S A R A N G S U R E S H H O T C H A N D A N I

TUMOR LIKE SWELLINGS OF JAWS• In olden time, tumor meant Lump or swelling due to any cause.

• In contemporary science, tumor means neoplasm that has formed lump/swelling in any part of body.

NEOPLASM….?

Abnormal Growth of Tissues.

Cyst• Odontogenic & Non

Odontogenic

Tumor/Neoplasm• Odontogenic & Non

Odontogenic• Metastatic

Giant Cell Lesion Fibro osseous LesionSwellings of

INTRODUCTION… •As the name indicates, odontogenic tumors are derived from odontogenic tissues. –Odontogenic tissues are those which take part in tooth development.

•Odontogenic Tumors are most common types of neoplasm of jaws.

CLASSIFICATIONOd

Benign

Epithelium

Ameloblastoma

Squamous Odontogenic

TumorCalcifying epithelial

odontogenic tumorAdenomatoid

odontogenic tumor

Calcifying cystic tumor

Mesenchymal

Odontogenic fibroma

Odontogenic myxoma

cementoblastoma

Mixed of Both Ameloblastic Fibroma

Malignant

Epithelium

Odontogenic carcinomaClear cell

odontogenic tumor

Mesenchymal Odontogenic sarcoma

INTRODUCTION

• Benign but locally invasive neoplasm derived from one of the following odontogenic epithelium;

– Surface epithelium– Reduced enamel

epithelium– Remnants of dental

lamina – Rest cells of Malessez – Lining of dentigerous

• It is rare & accounts for 1% of all tumors of oral cavity.

• BUT,

Ameloblastoma is common in our Society. (PAKISTAN)

TYPES OF AMELOBLASTOMA

Ameloblastoma On the basis of Clinical & Radiological Features.

Central / Intra Osseous

Multicystic Ameloblastoma

Solid Ameloblastoma Conventional

Ameloblastoma Follicular

Ameloblastoma True Ameloblastoma

Unicystic

Peripheral / Extra

Osseous

GENERAL FEATURES OF AMELOBLASTOMA• Most common neoplasm of

odontogenic origin.

• Usually in 3rd – 5th decade. – Rare in children & elderly– Mostly in posterior region of

mandible.

• No specific gender prediction.

• Locally invasive but does not metastasize

– That’s why called benign.

• About 80% of Ameloblastoma occur in Mandible.

CLINICAL PRESENTATION OF AMELOBLASTOMA• Usually asymptomatic & slow

growing.

• Results in facial deformity & jaw expansion.

• In maxilla even large lesion of Ameloblastoma produce very little expansion because lesion can extend into sinuses & beyond.

• Characteristics of Jaw Expansion by Ameloblastoma

–Bony hard, non tender, ovoid or fusiform outline.

– in advanced cases egg shell crackling due to thinning of bone.

A CLINICAL PHOTOGRAPH OF GRANULAR CELL AMELOBLASTOMA IN THE ORAL CAVITY SHOWS AN ENORMOUS MASS ON THE RIGHT MANDIBLE.

http://www.nature.com/ijos/journal/v4/n1/full/ijos20129a.html

C L IN IC AL PRE SE N TAT IO N (LATE FEATURES) OF AMELOBLASTOMA

•Pain

•Paresthesia

•Perforation of

•Extension of neoplasm into soft tissue.

R A D I O G R A P H I C

F E A T U R E S OF AMELOBLASTOMA

Typically form Rounded & Cyst like Radiolucency with moderately well defined margins and appear as multilocular – SOAP BUBBLE or HONEY COMB APPEARANCE.

A panoramic radiograph displays a well defined multi locular radiolucency with scalloped border (arrowheads) extending from the right second mandibular premolar to the mandibular ramus. Extensive root resorption of the right second mandibular premolar and thinning of the cortical plate is detected. Note that the inferior alveolar nerve canal has been displaced inferiorly to the inferior cortex of the mandible (arrows).

http://www.nature.com/ijos/journal/v4/n1/full/ijos20129a.html

HISTOPATHOLOGY OF AMELOBLASTOMA• Conventional ameloblastoma are usually made of mixture of solid neoplasm & cysts.• They have variety of patterns histologically but there are some features

which are common to all histological variety of ameloblastoma;

–Presence of neoplastic ameloblasts with Palisaded appearance & reverse polarization (presence of nuclei away from basement membrane)

Follic

FOLLICULAR AMELOBLASTOMA• Most common type of ameloblastoma.• Characterized by; islands of follicles of

epithelial cells in a connective tissue stroma. – Outer layer of these islands have well organized,

tall columnar ameloblasts like cells with reverse polarity which are surrounding core of polyhedral or angular cells.

– small cysts may be present within follicle or stoma – Here islands of epithelium are not interconnected.

FOLLICULAR AMELOBLASTOMA

PLEXIFORM AMELOBLASTOMA• Here epithelium forms cords or strands

and trabeculae of small, darkly stained epithelial cells which may lack reverse polarization and does not resemble any stage of ameloblasts present in less cellular stroma.

• This variant give Fish – net appearance.

ACANTHOMATOUS AMELOBLASTOMA• It has similar histological appearance to

follicular ameloblastoma, except difference in;

– Squamous metaplasia of core cells (stellate & angular cells) occurs producing prickle cells & keratin in core.

• this variant is sometimes confused with squamous cell carcinoma.

BASAL AMELOBLASTOMA• Rare type

• Arranged as trabecular pattern with peripheral cells cuboidal rather than columnar.

• Mistaken with basal cell carcinoma.

GRANULAR AMELOBLASTOMA• In this appearance of epithelium & stroma is

also similar to follicular ameloblastoma but difference in it is; central / core cells & some ameloblasts at peripheral cells undergo degenerative changes & form sheets of large PINK / eosinophilic granular cells in the center of island.

DESMOPLASTIC AMELOBLASTOMA• In this epithelium, odontogenic epithelium is arranged in small islands or cords in dense & highly collagenised stroma.

BEHAVIOR OF AMELOBLASTOMA• Although ameloblastoma is benign, but some cells of

this ameloblastoma may infiltrate the narrow spaces without causing swelling and destruction of bone.

• So that’s why simple curettage or enucleation of lesion cannot be done due to high recurrence.

• So surgical resection with small normal tissue is best treatment option. (wide excision)

MANAGEMENT OF MULTICYSTIC AMELOBLASTOMA• Diagnosis is confirmed by biopsy.

• Treatment of choice is wide excision – taking upto 2 cm of normal bone around margin of lesion.

– Simple enucleation can cause Recurrence because of probability of invasion in surrounding space.

• Regular radiographic follow up for detecting any recurrence.

MANAGEMENT OF MULTICYSTIC AMELOBLASTOMA•Maxillary Ameloblastoma are dangerous because;

–Bone is thinner in mandible. –Neoplasm spread easily to following areas in

maxilla. • Maxillary sinus • Pterygomaxillary fossa • Orbit • Cranium • Brain

UNICYSTIC AMELOBLASTOMA

INTRODUCTION UNICYSTIC AMELOBLASTOMA• It is defined as ameloblastoma having single cyst or appear as single cyst.

• However, ameloblastoma radiographically appearing as single cyst can be Multicystic like mural ameloblastoma

Explanations for a Unicystic presentation of ameloblastoma radiologically. The two patterns on the left are true Unicysticameloblastoma while that on the right is aconventional ameloblastoma with one verylarge cyst.

FEATURES OF UNICYSTIC AMELOBLASTOMA• Mostly b/w 10 – 20 years of

age.• Mostly in posterior mandible.• Sometimes arises with

dentigerous cysts.

• Radiological Features– Appear as unilocular radiolucency

• Histology– Tumor cells forming cyst

wall are flattened & can be mistaken for those or non – neoplastic cyst.

• Treatment – Enucleation

PERIPHERAL AMELOBLASTOMA• In this type, ameloblastoma is present in gingival or alveolar soft tissues

and does not involve bone.

• These lesion may arise from;– Basal cells of oral epithelium– Extra osseous rests of dental lamina.

• Histologically similar to intra osseous ameloblastoma.

MALIGNANT OR METASTASIZING AMELOBLASTOMA• It is distant or metastasized ameloblastoma.• Metastasis usually occur to lung. • Although it is benign and truly speaking does not

metastasize but in some conditions as described under they may move from oral cavity to other places;

– Aspiration of some cells of ameloblastoma into lungs during surgery.

– Surgically disrupting primary site – Incomplete removal

AMELOBLASTIC CARCINOMA

• It arises when dysplastic changes occur in the primary benign ameloblastoma. • Rare •Histologically poorly differentiated and shows dysplasia .•Metastasize to lymph nodes.• If metastasis is present, prognosis is poor.

MALIGNANT AMELOBLASTOMA

• Clinically primary & secondary ameloblastoma have same all clinical histological & other features.

• Usually lungs.

• Primary has features of normal benign ameloblastoma, while secondary show dysplasia & malignant .

• Metastasize to lymph nodes.

Ameloblastoma (Odontogenic Tumor) Oral Pathology

Health & Medicine