1-52 Cellular Adaptation and Neoplasia

Question 1

Cellular homeostasis/Adaptation

Answer 1

• Hypertrophy: increase in cell size and metabolic activity
• Atrophy: decrease in cell size/number and metabolic activity
• Hyperplasia: increase in cell number
• Metaplasia: transformation of one differentiated cell type to another

Question 2

Physiologic vs pathologic stimuli

Answer 2

Physiologic stimuli are expected and normal

• -puberty
• -pregnancy
• -often mediated by hormones

Pathologic stimuli are abnormal and innappropriate

• -traumatic injury
• -infection
• -environmental toxins

-Plasia: means growth or change

• •Increase in cell number, orderly and physiologic proliferation of cells
• •Ex. squamous epithelium when irritated
• •Ex. breast tissue (lobular hyperplasia) during pregnancy

Question 3

Regeneration

Answer 3

• Grows back with normal strucutre and function
  
  • Hyperplasia but with approraite cell differentiation
  • Ex. Liver regeneration

Question 4

Metaplasia

Answer 4

• •Transformation of one type of differentiated tissue into another type of tissue.
• •Can be a response to physiologic or pathologic stress
• Normal examples: Cervix during menarche, Esophagus as a result of reflux (barrett’s esophagus)

Pathologic examples: lungs from ciliated columnar epithelium to stratefied epithelium metaplasia

Cells dont return to normal but the TISSUE can return to normal

Question 5

Dysplasia

Answer 5

Dysplasia: disordered growthin epitherlial tissues

• pre-malignant
• Characterized by:
  
  • -Loss of uniformity of cells
  • -Loss of architectural orientation
  • -Pleomorphism (variation in cell size and shape)
  • -Anaplasia (lack of differentiation)
  • -Increased nuclear-to-cytoplasmic ratio
  • -Increased mitoses
• Ex: cervical HPV infection can cause dysplasia that can regress to normal tissue or progress to neoplasia

Question 6

Nomenclature of tumors

Answer 6

1. Line of differentiation
2. Benign (pathology perspective) or malignant
   
   • •-carcinoma – malignant epithelial neoplasm
   • •-sarcoma – malignant mesenchymal neoplasm
   • •Lymphoma – malignant lymphocytic neoplasm
   • •Melanoma - malignant melanocytic neoplasm
   • •-oma – benign neoplasm**

Important exception: Adenomas of the GI tract are not truly “benign”, but rather dysplastic lesions that can evolve into invasive malignant neoplasms (carcinomas)

Question 7

Grade and Stage of Cancer

Answer 7

• Grade: degree of histologic differentiation
  
  • How well differentiated a cell is
• Stage: evaluation of the extent of tumor spread
  
  • established to detmine clinical prognosis
  • TIssues (1-4), Nodes (0-3), Metastatic (0-1)