Predictive factors for sufficient cytological result after first nondiagnostic thyroid fine-needle aspiration biopsy result

Dellal Kahramanca Fatma Dilek; Nagihan Bestepe; Kiran Merve Meryem; husniye başer; Didem Ozdemir; Oya Topaloglu; Reyhan Ersoy; Bekir Cakir

doi:10.1530/endoabs.90.P772

Aim: To determine whether there is any factor that can predict sufficient results in second thyroid fine-needle aspiration biopsy (FNAB) after first nondiagnostic cytological result.

Materials and method: Nodules with non-diagnostic result after first FNAB were included and separated into two groups as sufficient (Group-1) and insufficient (Group-2) second FNAB.

Results: Second FNAB was performed on 643 nodules of 443 patients with initial nondiagnostic cytology. The result was diagnostic in 437(68.0%) nodules (Group-1) while it was again nondiagnostic in 206(32.0%) (Group-2). Thyroid autoantibody positivity were similar in groups. Cystic/mixed structure and heterogeneous echogenity were more frequent in Group-2 (P=0.020 and P=0.011, respectively). Solid structure and isoechoic appearence were more frequent in Group-1 (P=0.003 and P=0.020, respectively). Border regularity, micro/macrocalcification, taller-than-wide shape, presence of halo were comparable in two groups (P>0.05). There were also no significant differences in terms of nodule dimensions, volume and rate of subcentimeter nodule between two groups(P>0.05). In multivariate analysis, likelihood of sufficient cytology was 1.943 times higher in isoechoic nodules in comparison to heterogeneous nodules(95 CI:1.253-2.977, P=0.003), whereas the effect of nodule structure on sufficient result became insignificant(P=0.432). Sufficient results group were cytologically distributed as 299 (68.4%) benign, 131 (30.0%) AUS/FLUS, 2 (0.5%) FN/SFN, 1 (0.2%) SFM and 4 (0.9%) malignant. 35 patients in Group-1 and 20 patients in Group-2 underwent thyroidectomy. Malignant histopathology was observed in 12/60(20%) nodules in Group-1 and in 3/37(8.1%) nodules in Group-2 (P=0.116)(Table).


	Sufficient result after nondiagnostic biopsy (n=437, 68.0%)	Insufficient result after nondiagnostic biopsy (206, 32.0%)	P
AntiTPO positivity (n=606)	85 (20.6%)	28 (14.5%)	0.074
Anti-TG positivity (n=600)	89 (21.8%)	33 (17.3%)	0.204
Subcentimeter nodule	35 (8.0%)	18 (8.8%)	0.747
Taller-than-wider	51 (11.7%)	15 (7.3%)	0.085
Irregular border (n=304)	188 (89.5%)	77 (81.9%)	0.067
Echogenity (n=587)			0.005
Isoechoic	314 (77.3%)	118 (64.5%)	0.001
Hypoechoic	26 (6.4%)	18 (9.8%)	0.143
Heterogenous	66 (16.3%)	47 (25.7%)	0.0071
Nodule texture			0.038
solid	404 (92.4%)	180 (87.4%)
cystic/mixt	33 (7.6%)	26 (12.6%)
Microcalcification	26 (5.9%)	8 (3.9%)	0.275
Macrocalcification	36 (8.2%)	21 (10.2%)	0.415
Presence of halo	72 (16.5%)	26 (12.6%)	0.204
Histopathology, malignant (n=97)	12 (20.0%)	3 (8.1%)	0.116
Nodule Dimensions (mm, median (IQR))
Anteroposterior	8.8 (7.0-12.6)	9.1 (6.8-12.8)	0.780
Lateral	11.9 (9.5-16.2)	11.8 (9.3-16.6)	0.948
Longitudinal	13.1 (10.9-19.4)	13.6 (10.7-19.1)	0.804
Nodule Volume (cm³, median (IQR))	0.71 (0.39-2.03)	0.69 (0.37-1.91)	0.993
IQR:interquartile range

Conclusions: Heterogeneous echogenity and cystic/mixt structure were more frequent in insufficient group, but after multivariate analysis, only isoechoic texture was determined to predict sufficient cytological result in rebiopsy. Second biopsy should be done to all nondiagnostic nodules because of comparable malignant histopathology results.

Endocrine Abstracts

P772