Malignant tumor-macro

Tumors Overview

  • Tumors can be classified as benign or malignant based on their characteristics and tissue of origin.

1. Nomenclature of Tumors

Tissue of Origin

  • Connective Tissue and Derivatives

    • Benign: Fibroma, Lipoma, Chondroma, Osteoma

    • Malignant: Fibrosarcoma, Liposarcoma, Chondrosarcoma, Osteogenic sarcoma

  • Endothelium and Related Cell Types

    • Benign: Hemangioma, Lymphangioma, Meningioma

    • Malignant: Angiosarcoma, Lymphangiosarcoma, Invasive meningioma

  • Blood Cells and Related Cell Types

    • Benign: None

    • Malignant: Leukemias, Lymphomas

  • Muscle Types

    • Benign: Smooth and Striated Leiomyoma, Rhabdomyoma

    • Malignant: Leiomyosarcoma, Rhabdomyosarcoma

  • Skin and Epithelial Tissues

    • Benign: Squamous cell papilloma, Basal cell carcinoma, Nevus

    • Malignant: Squamous cell carcinoma, Adenocarcinoma, Malignant melanoma

  • Glandular Structures

    • Benign: Adenoma, Cystadenoma

    • Malignant: Adenocarcinoma, Cystadenocarcinoma

  • Germ Cell Tumors

    • More than one neoplastic cell type

2. Macro- and Microscopic Aspects of Tumors

Benign Tumors Characteristics

  • Well-circumscribed, sometimes encapsulated

  • Slow, expansive growth; no metastases

  • Mobile on palpation

  • Varying sizes, rarely ulcerated

  • Histologically: Mature tissue resembling origin, homogeneous cell characteristics, rare mitosis

Malignant Tumors Characteristics

  • Poorly defined, infiltrative margins; not encapsulated

  • Rapid, infiltrative growth; frequent metastases

  • Immobile on palpation

  • Often ulcerated with varying sizes

  • Histologically: Immature, pleomorphic tissues with atypical mitoses

Specific Types of Carcinomas

1. Diffuse Infiltrating Gastric Carcinoma

  • Features: Thickened gastric wall, infiltrative nature

  • Characteristics: Malignant, ulcerated appearance

2. Colorectal Carcinoma

  • Involves intestinal mucosa, appears as protruding malignant tumors

3. Glandular Differentiation

  • Glandular tumors can arise from various epithelial sources (stomach, colon, etc.)

  • Grading system based on differentiation: well, moderately, poorly differentiated

  • Staging using pTNM system for depth, lymph node involvement, and metastases

4. Malignant Pulmonary Tumors

  • Centrally Located: Often infiltrative affecting lung structure

  • Peripherally Located: Can present with necrotic centers and metastases to lymph nodes

  • Multiple Lung Metastases: Often characterized by well-defined tumor nodules in lung parenchyma and specific imaging features

5. Metastasis Overview

  • Definition: Spread of cancer cells from the original site to distant organs

  • Common sites for metastasis include lungs, liver, and lymph nodes.