Classifying Lesions & Cytologic Criteria of Malignancy

what are the five categories of tissue lesions?

inflammatory

hemorrhagic

cystic

neoplastic

mixed cell populations

lesions with leukocytes in numbers above those expected from blood contamination that are classified based on cell type

inflammatory

inflammatory lesions with mostly neutrophils and macrophages can be described as

pyogranulomatous

inflammatory lesions with mostly macrophages can be described as

granulomatous

lesions caused by neutrophilic inflammation must have greater than ?% neutrophils

85%

neutrophilic change that occurs in tissues, primarily affects the nucleus, and indicates cell death/karyloysis

degenerative change

1 multiple choice option

neutrophilic change that occurs in peripheral blood, primarily affects the cytoplasm, and indicates systemic inflammation often due to infection

toxic change

1 multiple choice option

inflammatory pattern with primarily neutrophils and >15% macrophages seen with difficult to remove infectious agents/material, and furunculosis or panniculitis (e.g. ruptured keratin containing cysts, sterile fat necrosis)

pyogranulomatous inflammation

differentials for pyogranulomatous inflammation?

Foreign material

Injection site adjuvant response

Fungal (yeast, pythium, protothecosis)

Filamentous bacteria

Leishmaniasis

Furunculosis/panniculitis

lesions caused by eosinophilic inflammation have >?% eosinophilic component

10%

differentials for eosinophilic inflammation lesions?

Allergy/hypersensitivity

Foreign body response

Fungal/oomycetes

Parasitism

Eosinophilic granulomas

Paraneoplastic responses (e.g. mast cell neoplasia, T-cell lymphoma)

inflammatory lesions with predominantly lymphocytes (mixed or heterogenous population)

lymphoplasmacytic inflammation

differentials for lymphoplasmacytic inflammation?

Regressing histiocytoma

Site of chronic inflammation and/or antigenic stimulation

Associated with viral infection

Characteristics of lymphoplasmacytic inflammation that may raise concern for neoplasia?

monomorphic

no other inflammatory cells present

what causes macrophagic/granulomatous inflammatory lesions?

chronic long standing conditions

what indicates a hemorrhagic lesion on cytology?

macrophages that contain erythrocytes, hemosiderin, or hematoidin

amber rhomboid crystals that indicate a longer time course of hemorrhage (>1 week)

hematoidin

common examples of hemorrhagic lesions?

seroma

hematoma

cutaneous vascular growths (hemangioma, hemangiosarcoma)

body cavity effusions

lesions that contain fluid or degraded amorphous cellular material

cystic lesions

examples of common cystic lesions?

keratin-filled cysts

apocrine cyst

sebaceous cyst

cysts that contain keratinized epithelial cells, amorphous material, and cholesterol crystals

keratin-filled cysts (aka epidermal inclusion cyst, follicular cyst et. al)

cysts that typically deflate when aspirated, contain colorless to brown fluid, are often acellular/low in cellularity with a proteinaceous background on cytology, and tend to recur/refill

apocrine cyst or sebaceous cyst

where are apocrine/sebaceous cysts most commonly seen on the body?

head and neck region

lesion that contains both inflammatory and tissue cellularity (e.g. epithelial, mesenchymal)

mixed

how does cytology mimic malignancy with mixed lesions?

reactive hyperplasia/dysplasia occurs in response to inflammation (impossible to tell which came first)

neoplastic tumor type with high aspirate cellularity and angular/polyhedral shaped cells typically seen in sheets/clusters

epithelial

2 multiple choice options

neoplastic tumor type with low aspirate cellularity and oval/spindled shaped cells typically seen in aggreates

mesenchymal

neoplastic tumor type with high aspirate cellularity and round/oval shaped cells typically seen individually or in loose aggregates

round/discrete

for what tumor types are the criteria of malignancy most helpful?

epithelial and mesenchymal

What are the cytologic criteria for malignancy?

anisokaryosis

anisocytosis

increased nuclear to cytoplasmic ratio

increased mitotic cells or atypical/bizarre mitoses

prominent/irregularly shaped nucleoli

coarse or clumped chromatin

nuclear molding

multinucleation

criteria of malignancy characterized by nuclei that distort or compress adjacent nuclei

nuclear molding

criteria of malignancy characterized by >2x variation in nuclear size

anisokaryosis

criteria of malignancy characterized by >2x variation in cell size

anisocytosis

there is an increased index of suspicion for malignancy once >? criteria for malignancy are met

3

lesions with <3 criteria of malignancy, minimal pleomorphism, uniform N:C ratio, with a consistent size, shape, and number of nuceloli

hyperplasia or benign neoplasia

anisocytosis and anisokaryosis are collectively termed

pleomorphism

what neoplasms serve as exceptions to the criteria for malignancy?

round cell neoplasms

neuroendocrine neoplasms

some mesenchymal neoplasms

some epithelial neoplasms

round cell neoplasms that are often exceptions to criteria of malignancy?

lymphoid neoplasia

mast cell tumors

neuroendocrine neoplasms that are often exceptions to criteria of malignancy?

AGASACA

thyroid

mesenchymal neoplasms that are often exceptions to criteria of malignancy?

leiomyoma/leiomyosarcoma

myxoma/myxossarcoma

epithelial neoplasms that are often exceptions to criteria of malignancy?

hepatocellular

mammary

cellularity evaluated on cytology must be

intact

TF concurrent inflammation makes lesion classification difficult

T

1 multiple choice option

validity of cytology information obtained depends on

sample collection

slide preparation

experience of collecter

experience of interpretor