Cytologic Characteristics of Neoplasia

Basics

Atrophy: ß in size and weight of an organ

Hypertrophy: Ý in the size

Hyperplasia: Ý in the # of constituent cells or deviation from normal tissue patterns

Neoplasm (tumor): disordered growth of cells

benign: slow growing, easily separated from other tissues and lack ability to metastasize

malignant: abnormal proliferation of cells, often chaotic, and show invasive growth, metastases, and fatal if untreated

Carcinoma: all malignant tumors of epithelial origin

Sarcoma: malignant tumor derived from connective tissue

Dysplasia: abnormal cellular maturation; one of early manifestations of carcinogenesis (as is atypical hyperplasia)

may regress, remain stationary or progress over a period of time

Carcinoma-in-situ: carcinoma confined to surface of epithelium; basement memb (BM) remains intact

Microinvasive cancer: infiltrating carcinoma penetrating [the BM] to a limited extent

Cytologic Criteria of Malignancy

No single cytologic feature can establish a malignant diagnosis, however, certain cytologic criteria taken together, can favor the diagnosis of malignancy

Principle differences between malignant and normal cells:

morphological: arrangement, cell size (ß), cell shape (polymorphism; polyhedral Þ round/oval), nuclear size, chromatin structure (clumping), multinucleation

cytoplasmic: reveal origin and function of the cells (ie: squamous cell carcinoma attempt to produce keratin, adenocarcinoma attempt secretory activity)

cell relationships: #, distribution, and relationship of malignant cells; cellular differentiation

nuclear features: nuclear/cytoplasmic ratio (Ý), nuclear size (Ý), nuclear inclusions, nuclear membrane irregularities (Ý) and relationship to cell membrane, chromatin texture/distribution, presence and size of nucleoli (increase) and mitotic activity

Application of Cytology in screening of Squamous Abnormalities in Uterine Cervix (Pap test)

Ectocervix: squamous mucosa (lots of cytoplasm, small nucleus)

Endocervix: columnar (mucosin secretion) Þ undergo squamous metaplasia (normal process)

Transformation zone: zone between the squamous and columnar morphologies as between the ecto- and endocervix; however this zone moves further up the canal during squamous metaplasia

Problems can occur during squamous metaplasia Þ dysplasia (mild/moderate/severe) Þ carcinoma-in-situ

N/C ratio Ý : nucleus is bigger, cytoplasm is smaller

Nuclei become darker (hyperchromasia); more chromatin which stains dark (blue)

May result from human papiloma virus (HPV)

Descriptive diagnosis/Classification

squamous intraepithelial lesion (dysplasia)
low grade squamous intraepithelial lesion (low grade SIL)
cellular changes consistent with HPV infection
mild dysplasia/CIN 1
high grade squamous intraepithelial lesion (high grade SIL)
moderate dysplasia/CIN 2
severe dysplasia/CIN3
squamous cell carcinoma

pap smear – retrieve ecto- and endocervical cells

screening procedure (use speculum)
look at cytological features (presence of macrophages is normal)
if pap smear is abnormal, only then do you think about biopsy

Origins of Cytology Specimens

Female genital tract: vaginal smear, cervical scrape, endocervical sample, endometrial aspiration, FNA of palpable mass, radiologically guided FNA (fine needle aspiration)

Respiratory tract: sputum, bronchial lavage, bronchial brushing, radiologically guided FNA

Oral Cavity: scrape, FNA of palpable mass

Urinary tract: voided urine, Urinary tract washings and brushings, radiologically guided FNA

GI tract: brushings, washings, radiologically guided FNA

Breast: FNA, nipple secretions

Salivary glands, lymph nodes, thyroid: FNA

pancreas: FNA, pancreatic duct brushing

Body fluids: pleural, pericardial, ascitic fluid, cerbrospinal fluid