Histology and markers Flashcards
GIST
Mesenchymal neoplasm of interstitial cells of Cajal
C-kit (CD117) and CD34 positive
SCC
Malignant neoplasm of epidermal keratinocytes
Cellular atypia, intracellular bridges, keratin pearls, eosinophilic
Gene mutations include:
- TP53
- NOTCH
- HRAS
- CDKN2A
BCC
Malignant neoplasm of basal layer of epidermis
Histological features:
- Basophilic (purple)
- Usually epidermal preservation
- Peritumoral clefts
- Palisading cells around outside of nests
Gene mutations include:
- PTCH1
- TP53
Adenocarcinoma
Gland forming with marked desmoplasia
Markers:
- CEA
- CK20
- CDX2
Neuroendocrine tumour
Neoplasms which express neuroendocrine markers, of neural crest origin
Well-differentiated:
- Salt and pepper chromatin
- Organoid architecture
Poorly-differentiated:
- Sheets or nests of atypical cells
- Pleomorphic nuclei
- Abundant mitoses
Stain strongly for Synaptophysin
Markers include
- Chromogranin A
- Serotonin
- 5 Hydroxy-indoloacetic acid (HIAA)
- Gastrin
- Pancreatic polypeptide
- VIP
- Somatostatin
- Insulin
- Glucagon
- Calcitonin
Invasive ductal carcinoma
Atypical proliferation of epithelial ductal cells
Histological features:
- Cords and nests of tumour cells with variable gland formation
- Nuclear atypia
- Increased mitoses
Invasive lobular carcinoma
Atypical proliferation of epithelial cells lining breast lobules
E-cadherin negative (mutated)
Histological features:
- Small cells infiltrating breast tissue in single file
Melanoma
Malignant neoplasm of melanocytes in epidermis
Histological features include
- Cytological atypia
- Pagetoid spread
- Nests of melanocytes
- Atypical mitoses
- Increased apoptosis
Gene mutations include
- BRAF
- RAS
- NF1
- KIT
Subtypes of DCIS
Comedo Cribriform Papillary Micropapillary Solid
Generic histological features of cancer
Nuclear atypia Cytological atypia Increased mitoses/mitotic figures Increased apoptosis Basement membrane invasion
