Correlation between brush cytology results and histopathological examination in diagnostic evaluation of precancerous conditions and laryngeal cancer: A prospective study

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The accuracy of brush cytology as a diagnostic test for laryngeal cancer

Cytological examination	The actual status – “gold standard” Histopathological examination
	(+)	(−)	Total
(+)	40 (PD)	3 (FD)	43 (PD + FD)
(−)	4 (FU)	43 (PU)	47 (FU + PU)
	44 (PD + FU)	46 (FD + PU)	87 (PD + FD + FFU + PU)

Observed numbers of the classification of laryngeal findings conducted by a cytologist and histopathologist, and Cohen’s kappa value with quadratic weights and standard errors for κ

Cytologist	Histopathologist
	Benign lesion	LSIL	HSIL	Malignant lesion
Benign lesion	40	0	0	3
LSIL	4	7	0	0
HSIL	0	0	6	6
HISL with features of invasion	0	0	0	21
N = 87; Cohen’s kappa coefficient κ = 0.732; SE = 0.020; p < 0.0001

Cytological evaluation of laryngeal smear

Type of cytological preparation	ConventionalMade using a different method
Overall quality of the smear	Suitable for cytological evaluationSuitable for cytological evaluation, driedNot suitable for cytological evaluation (technical procedure was not performed, or technical procedure was performed but material is too dry, incorrectly preserved, cell concentration is low, material is not legible due to numerous inflammatory cells, erythrocytes)
Number of cells in the smear	High cell concentration K1Moderate number of cells K2Low cell concentration K3
Erythrocyte count in the smear	High erythrocyte count E1Low/moderate erythrocyte count E2Erythrocytes absent E3
Severity of inflammation	Minor inflammation INF1Moderate inflammation INF2Severe inflammation INF3
Type of inflammatory cells	Lymphocytes LGranulocytes GLymphocytes and granulocytes L and G
General characteristics of the smear	No intraepithelial neoplasia or cancer, only normal stratified squamous epithelial cells are presentAbnormal cytologyCells other than stratified squamous epithelial cells are present in the smear, glandular epithelium cells are present
Abnormal epithelial cells	Atypical squamous cells of undetermined significance ASC-USLow-grade intraepithelial lesion LSILHigh-grade squamous intraepithelial lesion HISLHigh-grade squamous intraepithelial lesion with features that raise suspicion of invasion (keratin pearl, keratin bundles, pathological mitoses)

Clinical characteristics of patients

Feature (variable)	Group B		Group K		Total		B vs K p
	N = 67		N = 25		N = 92
	n	(%)	n	(%)	n	(%)
Diagnosis:							<0.001
Laryngeal cancer	57	85.1	0	0.0	57	62.0
Leukoplakia	10	14.9	0	0.0	10	10.9
Polyp	0	0.0	10	40.0	10	10.9
Reinke’s edema	0	0.0	10	40.0	10	10.9
Cyst	0	0.0	5	20.0	5	5.3
Results of histopathological examination							<0.001
FI - benign lesion	21	31.3%	25	100.0%	46	50.0%
LSIL	7	10.4%	0	0.0%	7	7.6%
HSIL	6	9.0%	0	0.0%	6	6.5%
Malignant lesion	33	49.3%	0	0.0%	33	35.9%
Results of cytological examination:	N = 67		N = 23		N = 90		<0.001
FI - benign lesion	20	29.9%	23	100.0%	43	47.8%
LSIL	11	16.4%	0	0.0%	11	12.2%
HSIL	12	17.9%	0	0.0%	12	13.3%
HISL* (with features of invasion)	21	31.4%	0	0.0%	21	23.3%
ASC-US	3	4.5%	0	0.0%	3	3.3%

General characteristics of patients

Feature (variable)	Group B		Group K		Total		B vs K p
	N = 67		N = 25		N = 92
	n	(%)	n	(%)	n	(%)
Sex:							<0.001
Female	16	23.9%	18	72.0%	34	37,0%
Male	51	76.1%	7	28.0%	58	63,0%
Age:							0.011
M ± SD	64.1 ± 8.6		56.3 ± 14.4		62.0 ± 11.0
Me [Q1; Q3]	66 [60; 70]		59 [42; 67]		64 [57; 69]
Min – Max	26 - 79		34 - 85		26 - 85

Number (proportion) of diagnoses in 90 patients with laryngeal diseases made based on results of cytological and histopathological examinations

Result of brush cytology	Result of histopathological examination
	Benign lesionN = 44	LSILN = 7	HSILN = 6	Malignant lesionN = 33
FI - benign lesion	40 (44.4%)	0 (0.0%)	0 (0.0%)	3 (3.3%)
LSIL	4 (4.4%)	7 (7.8%)	0 (0.0%)	0 (0.0%)
HSIL	0 (0.0%)	0 (0.0%)	6 (6.7%)	6 (6.7%)
HISL* - with features of invasion	0 (0.0%)	0 (0.0%)	0 (0.0%)	21 (23.3%)
ASC-US - abnormal result	0 (0.0%)	0 (0.0%)	0 (0.0%)	3 (3.3%)