Classification of malignant tumours Flashcards
Malignant tumour of epithelium
Carcinoma
Types of carcinoma
Squamous cell carcinoma
Adenocarcinoma
What is squamous cell carcinoma?
from squamous epithelium - skin, oesophagus, cervix
(or from cells with the potential for squamous maturation eg squamous cell carcinoma of the bronchus arises in squamous metaplasia in the bronchus)
Prickle cell interdigitations/ keratin pearl
What is adenocarcinoma?
carcinomas arising from glandular epithelium, such as the colon, breast, stomach, pancreas, ovary, etc
Abnormal glands
Malignant tumours of connective tissues
Sarcoma
Types of sarcomas
Fibrosarcoma from fibrocytes Osteosarcoma from osteoblasts Chondrosarcoma from cartilage cells Leiomyosarcoma from smooth muscle cells Rhabdomyosarcoma from striated muscle
Malignant tumours of the germ cells
Teratocarcinomas
What are the exceptions?
Sometimes names persist for historical reasons, such as melanoma of the skin
seminoma of the testis
lymphoma in the lymph glands
all of which are malignant and life threatening
How are tumours graded?
degree to which the histological appearance and architecture of the tumour i.e. the DIFFERENTIATION (well, moderately, poorly differentiated) resembles that of the normal organ or tissue from which it was derived (also called GRADE: G1, G2, G3).
What is the stroma?
vascularised connective tissue surrounding and supporting neoplastic cells- very pronounced in carcinomas
What are the features of the stroma?
- The stroma is not neoplastic but is a host response to tumour growth: Cancer Associated Fibroblasts (CAF) secrete desmoplastic stroma
- Neovascularisation of tumours is essential for growth
- The extent and composition of the stroma depends upon the molecular signals from the tumour cells.
What are Hemopoietic system tumours called?
aemia suffix (blood)
Cancer of white blood cells
Leukaemia
What is classification of leukaemia based on?
their clinical course- acute or chronic
the cell lineage- myeloid or lymphoid
