Diagnostic value and safety of medical thoracoscopy for pleural effusion of different causes

Table 1 Characteristics of the study population (n = 106)

Variables	Total	Malignant (n = 54)	Tuberculous (n = 43)	Inflammatory (n = 9)	χ2/Z	P value
Age in yr	59 (49-68)	62 (54-70)	54 (43-66)a	58 (51-72)	7.359	0.025
Sex					1.723	0.427
Male	67 (63.1)	34	29	4
Female	39 (36.8)	20	14	5
Hospital stay in d	15.00 (12.00-17.25)	16.00 (14.00-19.25)	13.00 (11.00-17.00)a	15.00 (12.50-23.00)	7.773	0.021
Disease duration in d	30.00 (15.00-60.00)	30.00 (20.00-60.00)	30.00 (10.00-60.00)	30.00 (8.00-30.00)	3.375	0.185
Smoking history	41(38.7)	19	18	4	0.688	0.756
Personal tumor	12 (11.3)	9	1a	2	6.815	0.029
Family tumor	2 (1.9)	2	0	0	1.735	0.583
Tuberculous history	2 (1.9)	0	1	1	4.351	0.076
Hypertension	19 (17.9)	9	8	2	0.431	0.930
Diabetes	11 (10.4)	5	4	2	1.760	0.428
Coronary disease	6 (5.7)	3	3	0	0.336	1.000
Chronic lung disease	3 (2.8)	0	2	1	4.561	0.061
Other chronic diseases	25 (23.6)	12	10	3	0.745	0.744
Tuberculosis DNA	1 (0.9)	0	1	0	2.831	0.643
Tuberculosis triple antibody	13 (12.3)	3	10	0	7.807	0.080
Tuberculosis IgG antibody	5 (4.7)	2	3	0	4.518	0.310
MTB/RIF	4 (3.8)	1	1	2	8.230	0.061
T-SPOT	45 (42.5)	13	29 a	3	19.217	< 0.001
ESR in mm/h	28.00 (12.00-44.00)	25.50 (12.00-39.25)	27.00 (12.00-34.00)	62.00 (50.00-71.50)a, b	11.009	0.004
Side of effusion					6.521	0.151
Left	31 (29.2)	19	10	2
Right	52 (49.1)	28	21	3
Bilateral	23 (21.7)	7	12	4
Size of effusion					5.333	0.069
Small	2 (1.9)	0	1	1
Moderate	32 (30.2)	12	17	3
Large	72 (67.9)	42	25	5
Effusion appearance					14.815	< 0.001
Bloody	39 (36.8)	29	7	3
Non-bloody	67 (63.2)	25	36a	6
CEA in ng/mL	2.22 (1.25-4.66)	3.28 (1.73-9.10)	1.40 (0.89-2.3)a	1.45 (0.94-4.85)	21.293	< 0.001
NSE in ng/mL	16.29 (10.96-20.94)	16.44 (10.91-20.80)	16.65 (13.00-23.19)	11.40 (9.94-14.30)	3.934	0.140
CA125 in U/mL	75.63 (33.02-229.63)	65.15 (31.64-231.88)	84.89 (40.61-285.80)	84.73 (36.91-112.84)	0.830	0.660
SCCA in ng/mL	0.70 (0.50-0.90)	0.70 (0.50-0.80)	0.70 (0.50-1.00)	0.80 (0.55-1.15)	1.785	0.410
PROGPR in pg/mL	24.40 (17.28-35.38)	29.80 (19.58-37.38)	20.10 (15.80-27.50)a	25.90 (17.45-55.75)	7.874	0.020
CYFRA in ng/mL	3.35 (2.02-8.70)	5.51 (3.35-14.46)	2.06 (1.48-2.90)a	2.54 (1.38-9.90)	33.461	< 0.001
Characteristics of pleural effusion
LDH in U/L	279.00 (182.50-485.25)	333.50 (187.00-495.75)	245.00 (183.00-383.00)	699.00 (106.00-947.50)	2.950	0.229
Protein in g/L	43.50 (36.90-48.48)	42.15 (36.98-46.58)	46.00 (37.20-49.90)	43.00 (29.40-47.40)	2.008	0.366
Glucose in mmol/L	6.16 (4.97-7.31)	6.37 (5.15-7.33)	5.87 (5.07-7.08)	5.57 (3.97-10.67)	0.218	0.897
ADA in U/L	14.00 (8.00-31.00)	9.00 (7.00-13.00)	27.00 (16.00-37.00)a	17.00 (6.50-34.50)	26.167	< 0.001
Nucleated cell	1345.50 (770.75-2847.25)	950.00 (569.50-2089.25)	2283.00 (1312.00-3631.00)a	1000.00 (245.00-4430.00)	15.049	0.001
Mononucleated cell	1079.00 (584.25-2317.50)	753.50 (420.25-1629.50)	1889.00 (1057.00-3018.00)a	880.00 (206.50-3658.00)	17.186	< 0.001
Multinucleated cells	99.00 (48.00-304.75)	108.50 (54.75-257.25)	88.00 (37.00-335.00)	120.00 (47.50-1140.50)	1.331	0.514

^aP < 0.05 vs Malignant group.

^bP < 0.05 vs Tuberculous group.

ADA: Adenosine deaminase; CA125: Carbohydrate antigen 125; CEA: Carcinoembryonic antigen; CYFRA: Cytokeratin fragment; ESR: Erythrocyte sedimentation rate; LDH: Lactate dehydrogenase; MTB/RIF: Mycobacterium tuberculosis/rifampicin (rapid microbial resistance test method); NSE: Neuron-specific enolase; PROGPR: Pro gastrin releasing peptide; SCCA: Squamous cell carcinoma associated antigen; T-SPOT: T lymphocyte spot test.

Table 2 Etiological analysis of patients with pleural effusion (n = 106)

Etiology	Value	%
Malignancy	41	38.7 (41/106)
Pleural origin	5	12.2 (5/41)
Lung origin
Adenocarcinoma	28	68.3 (28/41)
Squamous carcinoma	1	2.4 (1/41)
Small cell carcinoma	3	7.4 (3/41)
Non-lung origin	4	9.8 (4/41)
Tuberculosis	21	19.8 (21/106)
Purulence	1	0.9 (1/106)
Nonspecific inflammation	11	10.4 (11/106)
Undiagnosed	32	30.2 (32/106)
Total	106	100.0 (106/106)

Table 3 Diagnostic yield of medical thoracoscopy

Etiology	Malignant				Tuberculous				Inflammatory
	T	D	UD	MD	T	D	UD	MD	T	D	UD	MD
n	54	41	13	0	43	21	19	3	9	12	0	3
Diagnostic yield, %	75.9				48.8				75.0
Accuracy, %	100				87.5				75.0

D: Diagnosis; MD: Misdiagnosis; T: Total; UD: Undiagnosis. Total is the total diagnosis numbers at discharge; Diagnosis is the diagnosis numbers under medical thoracoscopy (MT); Undiagnosis is the undiagnosed numbers under MT; Misdiagnosis is the diagnosis under MT inconsistent with the diagnosis at discharge or considered diagnosis after effective management. The inflammation diagnostic yield was calculated as the ratio of the final diagnosed number of 9 at discharge and the number of confirmed diagnosis of 12 under MT, and the diagnostic accuracy was obtained by 100% subtracting 25.0% (3/12, misdiagnosis rate).

Table 4 Thoracoscopic findings (n = 106)

Characteristic	n (%)	Malignant	Tuberculous	Inflammatory	χ2	P value
Single or multiple nodules	86 (81.1)	49	29a	8	8.335	0.011
Miliary nodules	9 (8.5)	1	8 a	0	8.228	0.012
Pleural hyperemia and edema	1 (0.9)	1	0	0	1.735	1.000
Pleural adhesions	36 (34.0)	15	15	6	4.937	0.084
Pleural thickening	2 (1.9)	0	2	0	2.656	0.326
Fibrous connective tissue and fibrous bands	13 (12.3)	5	8	0	2.953	0.244
Focal necrosis	6 (5.6)	3	3	0	0.336	1.000
Neoformation	3 (2.8)	3	0	0	2.330	0.428
Plaque-like lesions and carbon foam deposition	11 (10.4)	7	4	0	0.877	0.709

^aP < 0.05 vs malignant group.

Table 5 Complications of thoracoscopy (n = 106)

Complication	n (%)	Malignant	Tuberculous	Inflammatory	χ2	P value
Fever	11 (10.4)	4	7	0	4.403	0.250
Bleeding	2 (1.9)	1	1	9	0.767	1.000
Chest tightness	12 (11.3)	9a	1a	2	6.815	0.029
Subcutaneous emphysema	7 (6.6)	2	3	2	3.905	0.128
Local pain	44 (41.5)	21	19	4	0.396	0.874
Cutaneous infection at the entry site	2 (1.9)	1	1	0	0.767	1.000
Prolonged air leak	2 (1.9)	1	1	0	0.767	1.000
Others	4 (3.8)	2	2	0	0.365	1.000

^aP < 0.05 vs malignant group.

Table 6 Multivariate analyses of the malignant and tuberculous groups

Variable	β	SE	P value	OR	95%CI
					Lower	Upper
Age in yr	-0.042	0.037	0.259	0.959	0.892	1.031
Hospital stay in d	-0.032	0.125	0.800	0.969	0.758	1.238
Personal tumor	-1.223	1.865	0.512	0.294	0.008	11.385
T-SPOT	-2.259	1.467	0.124	0.105	0.006	1.854
ESR	0.007	0.032	0.814	1.008	0.946	1.072
Effusion ADA	0.212	0.109	0.052	1.236	0.998	1.530
Effusion appearance	-6.710	2.613	0.010	0.001	0.000	0.204
CEA	-1.413	0.559	0.011	0.243	0.081	0.728
PROGPR	-0.097	0.051	0.060	0.908	0.821	1.004
CYFRA	-0.064	0.038	0.091	0.938	0.870	1.010
Nucleated cell	0.001	0.000	0.263	1.001	1.000	1.002
Mononucleated cell	-0.001	0.001	0.354	0.999	0.998	1.001
Single or multiple nodules	2.143	2.008	0.286	8.526	0.167	436.395
Miliary nodules	-1.982	2.936	0.500	0.138	0.000	43.469
Chest tightness	5.356	2.817	0.057	211.770	0.848	52896.349

ADA: Adenosine deaminase; CEA: Carcinoembryonic antigen; CYFRA: Cytokeratin fragment; ESR: Erythrocyte sedimentation rate; OR: Odds ratio; PROGPR: Pro gastrin releasing peptide; T-SPOT: T lymphocyte spot test.