Neoplasia 3: Laboratory Diagnosis

Question 1

Histologic Method

Answer 1

1 - Routine Paraffin Embedding (excise whole tumor and stain it to identify)

2 - Frozen section for rapid dx (done when unsure if benign or malignant)

Question 2

Cytologic Method

Answer 2

1 - Fine Needle Aspiration Cytology (spill cells onto slide, stained, and dxed as benign or malignant) –> bone or lymph lumps

2 - Exfolicative cytology or PAP smears

Question 3

Immuno-histochemistry

Answer 3

Diagnosis of undifferentiated tumors

Cytokeratin filament: epithelial carcinomas (Squamous CC, and adenocarcinomas)

Desmin filament: muscle tumors

Vimentin: sarcomas –> connective tissue, cartialge, and bone tumors

Neurofilament: CNS PNS neurons (pheochromocytoma, neuroblastoma)

Glial fibrillary acidic protein (GFAP) : Glial cells (Astrocytoma, ependymomas)

Question 4

FISH

Answer 4

Fluorescence in-Situ Hybridizations
Detects translocations (bcr-abl fusion), oncogenes (N-myc), spectral karyotyping 

*DNA Micro-array analysis: sequences RNA. Detects multiple mutations in breast carcinomas

Question 5

Flow cytometry

Answer 5

Leukemias and lymphomas

Measures DNA content of cells, and aneuploidy

Detects malignancies on each and every individual cell.