patoloji-ders-notlari

Title

Serdar Balcı

Characteristics of Benign and Malignant Neoplasms

Serdar BALCI, MD

Benign vs Malignant

Benign

Malignant

Good news

Genetically simple

Few mutations

Curable

Robbins and Cotran’s Pathological Basis of Diseases

Robbins Basic Pathology

DIFFERENTIATION

Differentiation

MUIR’S TEXTBOOK OF PATHOLOGY

Leiomyoma of the uterus

Robbins and Cotran’s Pathological Basis of Diseases

Malignant Neoplasms

Well Differentiated

Moderately Differentiated

Poorly Differentiated

Undifferentiated

Anaplastic

Differentiation is defined as “grade” in certain classification shemes.

Grade is determined microscopically

Adenocarcinoma of Colon

Robbins and Cotran’s Pathological Basis of Diseases

Urologic Surgical Pathology, 3 rd __ Ed__

Urologic Surgical Pathology, 3 rd __ Ed__

Urologic Surgical Pathology, 3 rd __ Ed__

Well-differentiated squamous cell carcinoma of the skin

Robbins Basic Pathology

Well-differentiated squamous cell carcinoma of the skin

Similar to normal squamous cells

Robbins Basic Pathology

Rubin’s Pathology 7th Ed

Anaplastic tumor of the skeletal muscle (rhabdomyosarcoma)

Robbins Basic Pathology

Anaplastic tumor of the skeletal muscle (rhabdomyosarcoma)

Prominent nucleoli

Does not resemble any cell

Hyperchromatic nuclei

Fragmanted nuclei

Increased nuclear size

Increased N/C ratio

Irregular nuclear contours

Robbins Basic Pathology

Anaplasia: backward formation

Lack of differentiation is a hallmark of cancer

Dedifferentiation

Loss of the structural and functional differentiation of normal cells

Dedifferentiation or failure/ arrest in differentiation (stem cell origin)

Robbins Basic Pathology

Pleomorphism: variation in size and shape of nuclei

Atypical mitosis

Tripolar

chromatin is coarse and clumped

increased N/C ratio 1:1 (normal: 1:4-1:6)

Robbins Basic Pathology

Rubin’s Pathology 7th Ed

Rubin’s Pathology 7th Ed

Malignant tumor features: increase as tumor approaches anaplasia

Well differentiated tumors retain normal function and morphology

Cancers of endocrine organs secrete hormones

Squamous cell carcinoma produce keratin

Hepatocellular carcinoma secrete bile

Some cancers function unexpectedly

Stromal Changes

Dysplasia

Urologic Surgical Pathology, 3 rd __ Ed__

Urologic Surgical Pathology, 3 rd __ Ed__

Robbins Basic Pathology

Carcinoma in situ

Hypechromasia

Mitosis in upper layers

Polarity is not preserved

No maturation

No normal stratified layer

Basal layer is intact

Robbins Basic Pathology

Carcinoma in situ

Robbins Basic Pathology

RATE OF GROWTH

How long does it take to produce a clinically overt tumor mass?

Until we detect it, tumor completed most of its lifespan

Rate of Growth

Robbins and Cotran’s Pathological Basis of Diseases

Rate of Growth depends on

the doubling time of tumor cells

the fraction of tumor cells that are in the replicative pool

the rate at which cells are shed or die

Rate of Growth is determined by

Rate of Growth and Necrosis

Rapidly growing malignant tumors contain central areas of ischemic necrosis

Tumor blood supply fails to keep pace with the oxygen demand

In benign tumors necrosis may occur, degenerative type necrosis

In malignant tumor necrosis is abrupt, tumor necrosis

LOCAL INVASION

Local invasion is not seen in benign tumors

Robbins Basic Pathology

Robbins Basic Pathology

Tumor Capsule

MUIR’S TEXTBOOK OF PATHOLOGY

MUIR’S TEXTBOOK OF PATHOLOGY

Local Invasion in Malignant Tumors

Malignant tumors should be removed with a wide margin of surrounding normal tissue because of this growth pattern

Surgical pathologists examine the margins of resected tumors to ensure that they are devoid of cancer cells (clean margins)

Like metastases, local invasiveness is the most reliable feature that distinguishes malignant from benign tumors

Robbins Basic Pathology

Robbins Basic Pathology

MUIR’S TEXTBOOK OF PATHOLOGY

Rubin’s Pathology 7th Ed

Adenocarcinoma of Colon, invading pericolonic adipose tissue

Robbins and Cotran’s Pathological Basis of Diseases

METASTASIS

Metastasis

Secondary implants of a tumor

Discontinuous with the primary tumor

Located in remote tissues

Robbins Basic Pathology

30% of patients with newly diagnosed solid tumors present with clinically evident metastases

20% have occult (hidden) metastases at the time of diagnosis

The more anaplastic and the larger the primary neoplasm, the more likely is metastatic spread

Invasion and Spread

Spread on body cavities

Lymphatic spread

Pathology - The Big Picture

Skip Metastasis

Do not follow usual route

Miss one lymph node and develop metastasis in the next one

Sentinel lymph node

The first lymph node the tumor goes to

May be detected with certain dyes and radioactive methods

Hematogenous spread

Rubin’s Pathology 7th Ed

Not all metastasis can be explained anatomically

Prostate carcinoma goes to bone

Bronchogenic carcinoma goes to adrenals, brain

Neuroblastoma goes to liver, bone

Skeletal muscle have abundant vascular structures but not a place for metastasis

Homing of tumor cells

Robbins Basic Pathology

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What we talk in this lecture are generic statements.

Some “benign” tumors may cause death, so they are clinically not benign at all.

Some “very malignant” tumors respond to therapy more quickly.

Some well-differentiated tumors do not respond to therapy.