Pathology - Neoplasia 3

Front 1

Krukenberg Tumor

Back 1

a secondary ovarian malignancy whose primary site arose in the gastrointestinal tract - they are often found in both ovaries.

Front 2

Pseudomyxoma peritonei

Back 2

uncommon tumor known for its production of mucus in the abdominal cavity - Unlike most cancers, PMP rarely spreads through the lymphatic system or through the bloodstream. PMP is most commonly associated with cancer of the appendix; mucinous tumors of the ovary have also been implicated.

Front 3

Pathways of Spread:
Seeding of body cavities and surfaces.

Back 3

This may occur whenever a malignant neoplasm penetrates into a natural “open field.” Most often involved is the peritoneal cavity, but any other cavity – pleural, pericardial, subarachnoid, and joint spaces – may be affected. Such seeding is particularly characteristic of carcinomas arising in the ovaries, when, not infrequently, all peritoneal surfaces become coated with a heavy layer of cancerous glaze.

Front 4

Pathways of Spread:
Lymphatic spread

Back 4

Transport through lymphatics is the most common pathway for the initial dissemination of carcinomas, but it should be remembered that sarcomas may also use this route. The emphasis on lymphatic spread for carcinomas and hematogenous spread for sarcomas is misleading because ultimately there are numerous interconnections between the vascular and lymphatic systems. The pattern of lymph node involvement follows the natural routes of drainage.

Front 5

Pathways of Spread:
Hematogenous

Back 5

This pathway is typical of sarcomas but is also used by carcinomas. Arteries, with their thicker walls, are less readily penetrated than are veins. Arterial spread, however, may occur when tumor cells pass through the pulmonary capillary beds or pulmonary arteriovenous shunts or when pulmonary metastases themselves give rise to additional tumor emboli. The liver and lungs are most frequently involved secondarily in such hematogenous dissemination.

Front 6

First Steps of Metastasis

Back 6

Malignant cells break away from primary tumor and break down surrounding ECM. There is secretion of laminin receptors to create a bridge between tumor cell and basement membrane. Then there is breaking down of collagen by proteases.

Front 7

Roles of Tumor Stroma

Back 7

-vascularization (blood vessels are part of stromal tissue)
-invasion
-proliferation

Front 8

What types of vessels might tumors infiltrate?

Back 8

Small vessels, never big. It is believed that the large arteries have anti-protease activity.

Front 9

Metastatic cascade in hematogenous dissemination

Back 9

Tumor cells travel in aggregates. First, they penetrate the ECM and move into a vessel. Platelets coagulate around the tumor cell aggregate, creating a tumor embolism. It eventually attaches to the vessel wall, migrates through, restarts angiogenesis and proceeds with further growth.

Front 10

Is metastasis random?

Back 10

No. There is directionality. This is based on chemokines. The cancer cells have receptors that direct to organ with specific chemokines.

Front 11

TIMPs

Back 11

Tissue Inhibitors of Metallo Proteinases - family of four protease inhibitors (1-4)

Front 12

Matrix Metalloproteinase Regulation

Back 12

1. regulation of synthesis by GFs or cytokines
2. inhibition of synthesis by corticosteroids or TGF-beta
3. regulation of the activation of secreted precursors
4. blockage of the enzymes by TIMPs

Front 13

Cancer Stem Cells

Back 13

Cancer cells that possess characteristics associated with normal stem cells, specifically the ability to give rise to all cell types found in a particular cancer sample. They are proposed to persist in tumors as a distinct population and cause relapse and metastasis by giving rise to new tumors. Therefore, development of specific therapies targeted at CSCs holds hope for improvement of survival and quality of life of cancer patients, especially for sufferers of metastatic disease.

Front 14

Neoplasms found in patients with HIV.

Back 14

-Kaposi Sarcoma (tumor caused by Human herpesvirus 8)
-B-cell Non-Hodgkin's Lymphoma
-Primary Lymphoma of the brain (very rare in non-HIV patients)
-Invasive cancer of cervix

Front 15

Ulcer and Cancer

Back 15

Ulcer does not become cancer, but cancer can become an ulcer.

Front 16

Bcl

Back 16

Family of genes that govern mitochondria outer membrane permeability. They can be pro-apoptotic (eg, Bax) or anti-apoptotic (eg, Bcl-2).