Neoplasia

Introduction

Neoplasia Dental

• Contoh kasus: Ameloblastoma

Ameloblastomaa tumor of the jaw derived from remnants ofthe embryonic rudiment of tooth enamel—called also adamantinoma

Berdasarkan gambaran ro.foto kedua kasus ini apakah sudah bisa ditentukandiagnosa untuk neoplasma ?

Diagnosis Cycle

ClinicalRadiograph Histopathology

Clinicalexamination

Radiograph Histopathology

Contoh kasus: Pengangkatan tumor

Pengambilan jaringan

Implantasi bridge

Nomenclature

Neoplasia literally means “new growth”

Definition:

"an abnormal mass of tissue the growth of"an abnormal mass of tissue the growth ofwhich exceeds and is uncoordinated with thatof the normal tissues and persists in the sameexcessive manner after the cessation of thestimuli which evoked the change."

Characteristic

• Heritable (genetic) changes

– Allow excessive and unregulated proliferation that isindependent of physiologic growth-regulatory stimuli

• To be transformed and continue to replicate

• Have certain degree of autonomy• Have certain degree of autonomy

– Depend on their local environment and the nutritionalstatus of the host ??

– Not completely: because some still require endocrinesupport

Tumors

a neoplasm is often referred to as a tumor

Study: oncology: (from oncos, "tumor," andlogos, "study of")

benign

tumor

benign

malignant

Klasifikasi

• remain localized

• amenable to local surgical removal

• the patient generally survivesbenign

• collectively referred to as cancers

• invade and destroy adjacentstructures

• spread to distant sites (metastasize)to cause death

malignant

Basic ComponentAll tumors, benign and malignant, have twobasic components:

parenchyma

• the essential and distinctive tissue of an organ• the essential and distinctive tissue of an organor an abnormal growth as distinguished fromits supportive framework / neoplastic cells

stroma

• made up of connective tissue, blood vessels,and host-derived inflammatory cells

Benign Tumors

Nomenclature:designated by attaching the suffix -oma to the celltype from which the tumor arises– Ex: fibroma fibrous tissue– Ex: chondroma cartilago tissue– Ex: chondroma cartilago tissue– Ex: Adenoma glands like

How to Classified:– Microscopic pattern– Macroscopic pattern– Cells of originEx: papillomas finger-likes fronds

Polyps

Malignant TumorsThere are two type:

• Malignant neoplasms arising in mesenchymal tissue or itsderivatives

• designated by their histogenesis (i.e., the cell type ofwhich they are composed)

• Ex: fibrosarcoma, chondrosarcoma

sarcomas• Ex: fibrosarcoma, chondrosarcoma

• Malignant neoplasms of epithelial cell origin

• three germ-cell layers: mesoderm, ectoderm, endoderm

• Sometimes the tumor shows little or no differentiationand must be called poorly differentiated orundifferentiated carcinoma

• Ex: adenocarcinomas, squamous cell carcinomas

carcinomas

CARCINOMAS

• Mesoderm sel epitel tubulus ginjal

• Ektoderm kulit

• Endoderm sel epitel pelapis usus

– ex: Squamous Cell Carsinoma

– ex: Adenocarsinoma

Mixed Tumor

• Causa: konvergen differentiation

– ex: adenoma pleomorfik salivary gland

Comparison between a benign tumor of the myometrium (leiomyoma) and a malignant tumorof similar origin (leiomyosarcoma)

Example

Tissue of Origin Benign Malignant

Composed of One Parenchymal Cell Type

Connective tissue andderivatives

Fibroma Fibrosarcoma

Lipoma Liposarcoma

Chondroma Chondrosarcoma

Osteoma Osteogenic sarcoma

Example

Endothelial and relatedtissues

Benign Malignant

Blood vessels Hemangioma Angiosarcoma

Lymph vessels Lymphangioma LymphangiosarcomaLymph vessels Lymphangioma Lymphangiosarcoma

Synovium Synovial sarcoma

Mesothelium Mesothelioma

Brain coverings Meningioma Invasive meningioma

Characteristic of Benign and MalignantNeoplasm

Fundamental features:

• differentiation and anaplasia,

• rate of growth,• rate of growth,

• local invasion,

• metastasis

Differentiation & Anaplasia (1)

Differentiation:

• The differentiation of parenchymal cells refersto the extent to which they resemble theirnormal forebears morphologically andnormal forebears morphologically andfunctionally

– Normal cell ?

– Benign and Maligna ?

• Squamous cell carcinoma (well differentiated)

Anaplasia:• Malignant neoplasms that are composed of

undifferentiated cells are said to be anaplastic• Anaplastic cells display marked pleomorphism (i.e., marked

variation in size and shape)• the nuclei are extremely hyperchromatic (darkly stained)

Differentiation & Anaplasia (2)

• the nuclei are extremely hyperchromatic (darkly stained)and large.

• The nuclear-to-cytoplasmic ratio may approach 1 : 1instead of the normal 1 : 4 or 1 : 6.

• Giant cells that are considerably larger• Anaplastic nuclei are variable and bizarre in size and shape.

• Anaplasia

Rate of Growth

The rate of growth of malignant tumors correlates ingeneral with their level of differentiation

Recently research:

• Cancer stem cells, sometimes called tumor-initiating• Cancer stem cells, sometimes called tumor-initiatingcells, were identified in breast cancer, glioblastomamultiforme (a brain tumor), and acute myeloidleukemia.

• These findings have important implications for cancertreatment Therapies kill the progeny of cancerstem cells capable of regenerating the tumor.

• Fibroadenoma of the breast

The tan-colored, encapsulated small tumor is sharply demarcated from thewhiter breast tissue

Local Invasion (1)

Benign

• Remains localized at its site of origin.

• It does not have the capacity to infiltrate,invade, or metastasize to distant sitesinvade, or metastasize to distant sites

– most develop an enclosing fibrous capsuleseparate from host tissue

– not all benign neoplasms are encapsulated

• Ex: leiomioma

Local Invasion (2)

Malignant

• Cancers grow by progressive infiltration,invasion, destruction, and penetration of thesurrounding tissuesurrounding tissue

– local invasiveness is the most reliable feature thatdistinguishes malignant from benign tumors.

Downloaded from: StudentConsult (on 2 December 2010 09:25 AM)

© 2005 Elsevier

Downloaded from: StudentConsult (on 2 December 2010 09:25 AM)

© 2005 Elsevier

Benign or Malignant ?

Metastasis

• The term metastasis connotes thedevelopment of secondary implants(metastases) discontinuous with the primarytumor, in remote tissues

• Malignant neoplasms disseminate by one ofthree pathways:(1) seeding within body cavities

(2) lymphatic spread

(3) hematogenous spread

• A liver studded with metastatic cancer