MED201 Neoplasia 1 PDF

Neoplasia 1 Dr Mohammed J Alyousef [email protected] Dr Awadia S Awadalla [email protected] Objectives 1 Recognise the terminology of neoplasms 2 Describe the pathologic features of benign tumors 3 Describe the pathologic features of malignant tumors 4 Discuss the pathways of tumors spr...

Neoplasia 1 Dr Mohammed J Alyousef [email protected] Dr Awadia S Awadalla [email protected] Objectives 1 Recognise the terminology of neoplasms 2 Describe the pathologic features of benign tumors 3 Describe the pathologic features of malignant tumors 4 Discuss the pathways of tumors spread Neoplasia literally means “new growth.” Benign Neoplasm Malignant Benign Microscopic and gross characteristics are innocent Remain localized Amenable to local surgical removal Malignant Invade and destroy adjacent structures Spread to distant sites (metastasize) to cause death Cancers, derived from the Latin word for “crab” Benign Tumors- Terminology • Attaching the suffix -oma to the cell type • fibrous tissue = fibroma • cartilaginous tumor = chondroma • Adenoma: epithelial neoplasms derived from glands or produce gland-like structures Benign TumorsTerminology • Papilloma: benign epithelial neoplasm growing on surface that produce fingerlike fronds • Polyp: mass that project above mucosal surface Finger like fronds Malignant Tumors Terminology Solid mesenchymal tissues: Sarcomas Mesenchymal cells of the blood: Leukemias or lymphomas • fat-like cells = lipo sarcoma • chondrocyte-like cells = chondro sarcoma Malignant Tumors - Terminology Epithelial cells: Carcinomas Adenocarcinoma : grow in a glandular pattern Squamous cell carcinoma: produce squamous cells Mixed tumors • The progenitor cell has the capacity to differentiate down more than one lineage Teratoma • Mature or immature cells or tissues derived from more than one germ cell layer • Originate from totipotential germ cells: • Ovary • Testis • Midline embryonic rests with u4 Characteristics of Benign and Malignant Neoplasms Differentiation and anaplasia Local invasion Metastasis Well defrientiated squamous cell carcinoma 1. Differentiation and Anaplasia • Differentiation: Extent to which neoplasms resemble their parenchymal cells of origin, both morphologically and functionally • Anaplasia: lack of differentiation Lipoma • Benign neoplasms are composed of well-differentiated cells that closely resemble their normal counterparts Liposarcoma • Malignant neoplasms exhibit a wide range of parenchymal cell differentiation Anaplastic features • Pleomorphism • Hyperchromatism • Prominent single or multiple nucleoli • Increased nuclear-tocytoplasmic ratio • Tumor giant cells Anaplastic features • Atypical mitoses Anaplastic features • Loss of polarity Dysplasia • Dysplastic epithelium is recognized by a loss in the uniformity of individual cells and in their architectural orientation breast a e ricodot The of Fibroaderm I descri b ed Tomer Benign well g Local Invasion Malignant: infiltration, invasion, and destruction of surrounding tissues Benign: cohesive expansile masses that remain localized to their sites of origin Metastasis Metastasis is defined by the spread of a tumor to sites that are physically discontinuous with the primary tumor Benign neoplasms do not metastasize!! Metastasis Seeding within body cavities Lymphatic spread Hematogenous spread Metastasis Lymphatic spread is more typical of carcinomas Hematogenous spread is favored by sarcomas