Systemic Pathology

Neoplasia-Abnormal cell growth

Lipoma

Polyps

Malignant Melanoma

Glioma

    Examples

Tumor Type Cell/Tissue of Origin Benign Tumors Malignant Tumors

Mesenchymal tumors

FibroblastFat CellBlood Vessels Smooth muscle cellStriated muscle cellCartilage Bone Cell

FibromaLipomaHemangiomaLeiomyomaRhabdomyosarcomaChondomaOsteoma

FibrosarcomaLiposarcomaAngiosarcomaLeiomyosarcomaRhabdomyosarcomaChondrosarcomaOsteosarcoma

Epithelial tumors Squamous epitheliumTransitional epitheliumGlandular/ductal epitheliumNeuroendocrine cellsLiver cellKidney cell

Epithelioma (papilloma)Transitional cell papillomaAdenomaCarcinoidLiver cell adenomaRenal cell adenoma

Squamous cell carcinomaTransitional cell carcinomaAdenocarcinomaOat cell carcinomaLiver cell carcinomaRenal cell carcinoma

Blood cells and lymphocytes

White blood stem cellsLymphoid cells Plasma cells

LeukemiaLymphomaMultiple myeloma

Tumors of neural cell precursors

Neuroblast Ganglioneuroma Neuroblastoma

Tumors of glial cells and neural supporting cells

Glial cellsMeningial cellsSchwann cells

MeningiomaSchwannoma

Glioma Malignant Schwannoma

Germ cell tumors Embryonic cells Teratoma Embryonal carcinomaTeratocarcinoma

Characteristics of Benign Neoplasms Characteristics of Malignant Neoplasms

Slow growth Fast growth

Good prognosis Poor prognosis

Does not invade surrounding tissue. Often surrounded by capsule of connective tissue.

Invades and infiltrates surrounding tissue (forms metastases)

Strong resemblance to cell type of origin. Highly differentiated uniform cell population. 

Various degrees of deviation from cell type of origin: Well differentiated = reasonable resemblance Poorly differentiated = some resemblance Anaplastic = no resemblance

Normal nuclei, well developed cytoplasm (nuclear:cytoplasm ratio is 1:4 to 1:6)

Large nuclei, little cytoplasm (higher nuclear:cytoplasm ratio than normal cells, about 1:1)Pleomorphic cell population (variation in size/shape of cells/nuclei)

Normal amount of chromatin Structurally abnormal, wrong number of chromosomes

Only a few mitotic cells Lots of mitotic cells

Benign VS Malignant

Metastasis

Dysplasia

Carcinogenesis

A result of accumulated mutations.3 steps: Initiation, Promotion, ProgressionMutations can:

Activate oncogenesResult in loss of Tumor suppressor geneResult in Incorrect expression of genes regulating

apoptosisAffect other related genetic mechanisms

Clinical Manifestations

• Obstruction• Pressure• Cachexia• Paraneoplastic Syndrome

Diagnosis

Staging and Grading

• For classifying tumors• Staging: tumor size

and spread. (TNM system)

• Grading: state of differentiation (rated I to IV)

Treatment

The End