Neoplasia PDF

Neoplasia Neoplasia • Neoplasia = new growth • Tumor = neoplasm, abnormal mass of cell • Oncology = study of tumors (Oncos = tumor + ology = study of) Definition of Neoplasia: – New growths of cells that is uncoordinated with that of normal tissues – Cells have loss to normal growth controls Tu...

Neoplasia Neoplasia • Neoplasia = new growth • Tumor = neoplasm, abnormal mass of cell • Oncology = study of tumors (Oncos = tumor + ology = study of) Definition of Neoplasia: – New growths of cells that is uncoordinated with that of normal tissues – Cells have loss to normal growth controls Tumors – Benign – malignant Benign tumors : – Will remain localized – Cannot spread to distant sites – Usually can be locally excised – Patient generally survives Malignant neoplasms: – Can invade and destroy adjacent structure – Can spread to distant sites – Cause death if untreated Like normal tissue tumors have two basic components: – Parenchyma (functional tissue): made up of neoplastic cells – Stroma: made up of non-neoplastic, host-derived connective tissue and blood vessels Parenchyma: – Determines the biological behavior of the tumor – Is from where the tumor derives its name Stroma: – Carries the blood supply – Provides support for the growth of the parenchyma Nomenclature – Tumors: • prefix + suffix • Type of cell + (-oma) Examples: • Fibrous tissue: Fibro + oma = Fibroma • Fatty tissue: Lipo + oma = lipoma Examples • Cartilage chondro + oma = chondroma • Smooth muscle Leiomyo + oma = leiomyoma • Skeletal muscle Rhabdomyo + oma = rhabdomyoma Characteristics of Benign and Malignant Neoplasms • Differentiation and Anaplasia • Rate of growth • Local invasion • Evolution of Cancer and metastasis Differentiation and Anaplasia Differentiation: the extent to which the parenchymal cells of the tumor resemble their normal counterparts morphologically and functionally Differentiation and Anaplasia • Well differentiated = closely resemble their normal counterparts • Moderately differentiated • Poorly differentiated • Undifferentiated ( Anaplasia ) • Benign tumors = well differentiated • Malignant tumors = well differentiated -----> anaplastic Differentiation and Anaplasia • Histological examination of a tumor • Pleomorphism : variation in size • High nuclear/cytoplasm ratio ( N/C ratio) • Hyperchromasia ( dark cell ) • Mitosis ….?abnormal one (abnormal mitotic spindles) Change of nuclear size and shape: nuclear enlargement, elongation and overlapping. Chromatin characteristics: chromatin clearing, margination and glassy nuclei. Characterized by the presence of welldefined nidi of small uniform cells with frequent areas of tumor necrosis and micro-follicles with thyroglobulin Trabecular or solid pattern of follicles microfollicular, normofollicular or macrofollicular No nuclear features of PTC Invasion of adjacent thyroid parenchyma Display marked pleomorphism, high nuclear to cytoplasmic ratios, hyperchromatic nuclei, abnormal nuclear contours, prominent nucleoli, and loss of normal polarity Rate of growth • Benign tumors: • grows slowly • are affected by blood supply, hormonal effects , location • Malignant tumors : • grows faster • Correlate with the level of differentiationless differentiation higher rate of growth Local Invasion Remain localized Cannot invade Usually capsulated Progressive invasion Destruction Usually not capsulated Evolution of Cancer (Carcinoma) and Metastasis • Hyperplasia • Increased cell production • Hyperplasia may be a sign of abnormal or precancerous changes (pathologic hyperplasia • Can also be a sign of increased growth in number of normal cells (physiologic hyperplasia) • Dysplasia • Loss of the organizational structure of cells • They show pleomorphism, hyperchromasia, increased mitosis and loss of polarity (organelle organization) • Does not mean cancer • Does not necessarily progress to cancer • May be reversible • Carcinoma in-situ – Definition: an intraepithelial malignancy in which malignant cells involve the entire thickness of the epithelium without penetration of the basement membrane. – Only applies to epithelial neoplasms Metastasis • Development of secondary implants discontinuous with the primary tumor, in remote tissues • Generally, the more anaplastic and the larger the primary tumor, the more likely is metastasis • Metastasis : three pathways – Lymphatic spread • favored by carcinomas • Breast carcinoma → axillary lymph nodes • Lung carcinomas → bronchial lymph nodes – Hematogenous spread • favored by sarcomas • also used by carcinomas • veins are more commonly invaded • liver and lungs are the most frequently involved secondary sites – Seeding of the body cavities: pleural, peritoneal cavities and cerebral ventricles Paraneoplastic Syndromes • Rare disorders that are triggered by an altered immune system in response to a neoplasm • Nonmetastatic systemic effects that accompany malignant disease • Symptoms result from substances produced by the tumor, and they occur remotely from the tumor itself • Symptoms may be endocrine, neurologic, musculoskeletal, cardiovascular, cutaneous, hematologic, gastrointestinal, renal, or miscellaneous in nature • May be the first or most prominent manifestation of a cancer Miscellaneous Tumors and Cancers Epithelial Benign Tumors Classified on the basis of : • The cell of origin • Microscopic pattern • Macroscopic pattern Adenoma : benign epithelial neoplasms producing gland pattern, or derived from glands but not exhibiting a classical gland pattern Skin Sebaceous Adenoma Papilloma : benign epithelial neoplasms of squamous cells growing on any surface that produce microscopic or macroscopic finger-like pattern Skin Squamous Cell Papilloma • Malignant tumors: – Malignant tumor arising in mesenchymal tissue : SARCOMA • From fibrous tissue: Fibrosarcoma • From bone : Osteosarcoma • From cartilage : Chondrosarcoma • Malignant tumors arising from epithelial origin : CARCINOMA – Squamous cell carcinoma – Renal cell adenocarcinoma – Cholangiocarcinoma Other Malignant tumors: • • • • Melanoma ( skin ) Mesothelioma (mesothelium ) Seminoma ( testis ) Lymphoma ( lymphoid tissue ) Clinical Case CC: 82 y/o male with unintentional weight loss since 3 months ago. Also chronic cough reports sporadic episode of diarrhea Mhx: HTN, gastritis Meds: ACEI, PPI Social: 60 pack year smoker Gastroenterologist ordered an upper GI series