tirads iii nodules on ultrasound of thyroid abstract id -1213
TRANSCRIPT
TIRADS III nodules on ultrasound of thyroid
Abstract ID -1213
Literature Review• Thyroid nodules are common and ultrasound is the modality
of choice to characterize them.• TIRADS is used in our center to stratify cancer risk in thyroid
nodules.• Positive predictive value for malignancy in TIRADS 3 nodules
in literature is 1.7 – 7.3%. (ref: 1, 2)
• We aimed to audit the number of TIRADS 3 nodules which turned out to be malignant and have a closer look at their ultrasound features.
Korean J Radiol; 14:110-1171
Radiology; 260:892-8992
Objectives1. To assess the number of TIRADS 3 nodules
which were malignant on FNAC or histopathology
2. To assess the imaging features of TIRADS 3 nodules which was malignant on histopathology and compare them with benign thyroid nodules
Methodology
Total no. of USG thyroids = 670
TIRADS III nodules n = 102
With HPE= 51
Retrospective study• USG thyroids done in our institution over a period of 3
months (Jan – March 2014) were assessed by obtaining data from the PACS and clinical workstation
• Of these, TIRADS III lesions were studied
Inclusion criteria• Patients with TIRADS 3 thyroid nodules diagnosed
on USG of thyroid USG TIRADS 3:
well defined oval solid of mixed isoechoic nodules• Diagnostic FNAC or surgical histopathology at CMC,
Vellore
Exclusion criteria• Thyroid nodules of other categories: TIRADS 2,
TIRADS 4, TIRADS 5• Inadequate thyroid FNAC with no surgical
histopathology
Colloid nodules - TIRADS 2 TIRADS 4 and 5
Methodology contd…• Following additional features were assessed in these nodules:- Heterogeneous echotexture- Nodule in nodule sign: Subtle hypoechoic area within a
predominantly isoechoic oval nodule- Hypoechoic internal septa sign: Hypoechoic ill-defined
branching lines within the nodule- Thick non uniform halo
• TIRADS 3 nodules were compared with FNAC and histopathology diagnosis.
Statistical Analysis• Analysis was done using SPSS version 16.0 • Categorical variables were analysed using Pearson
chi-square test
• Continuous variables were analysed using independent sample t-test
Results
• Total number of nodules= 51• Age: 39.78 +/- 12.53 ( age range of 19- 72 years)• Male to female ratio: 11:40
• Total number of nodules with HPE/FNAC =51• Total number of cases with FNAC=41• Total number of cases with surgical HPE= 18
Malignancy in TIRADS III nodules• Number of benign nodules = 40• Number of malignant nodules = 11
• Incidence of malignant nodules among TIRADS 3 lesions on ultrasound thyroid is 11/ 102 = 11%
Total no= 51 No Percentage %Follicular variant papillary carcinoma thyroid
11 61
Adenomatous hyperplasia 04 22
Follicular adenoma 02 11
No follicular hyperplasia 01 6
Surgical Histopathology: ( n=18)
All malignant nodules (n=11) were encapsulated variety of follicular variant of papillary carcinoma thyroid.
Bethesda classification cytology (FNAC):
Bethesda class
No. of cases
%
I 01 1.9
II 34 66.6
III 03 5.8
IV 03 5.8
V 00 00
VI 00 00class I
class IIclass III
class IVclass V
class VI
0
5
10
15
20
25
30
35
class I = 1
class II= 34
class III= 3class IV =3
class V; 0class VI; 0
n=41
n=41
Results contd..
• Male patients has higher risk of TIRADS 3 nodule being malignant ( chi square= 4.73 ; p= 0.03)
• There was a positive trend towards malignancy when nodules had heterogeneous echotexture and hypoechoic internal septa sign
• Cystic change in the nodule tended to predict benign thyroid nodule (p = 0.06)
Results contd..• Combined criteria of “nodule within nodule”
appearance and hypoechoic internal septa” best predicted malignancy in the TIRADS 3 nodules. • Chi square= 29.5; p = 0.000
Diagnostic significance of combined criteriaDiagnostic performanceSensitivity 100%
Specificity 90.9%
Positive predictive value 63.6%
Negative predictive value 100%
ROC analysis: Area under the curve= 0.818 (0.64-0.99)
24 year old female patient follicular variant of papillary carcinoma
Well defined, oval, solid, isoechoic, heterogenous nodule with thick non uniform halo (arrows) and positive hypoechoic internal septa sign.
Eccentric hypoechoic focus within a isoechoic well defined nodule - positive nodule in nodule sign
37 year old female -Case of follicular variant of papillary carcinoma
Positive hypoechoic internal septae sign in another patients with FVPTC
24 year old female with benign follicular nodule
Well defined isoechoic nodule with cystic degeneration
48 year old male with histopathology diagnosis of follicular adenoma
Well defined homogenous isoechoic nodule with few cystic spaces -negative for nodule within nodule sign and hypoechoic internal septatae
Well defined isoechic hetrogenous nodule -positive for nodule within nodule sign -positive for hypoechoic internal septae sign-positive thick non uniform halo
54 year old man with histopathology diagnosis of follicular variant of papillary carcinoma
Conclusions• Encapsulated variety of follicular variant of papillary
carcinoma thyroid mimics benign thyroid nodules and usually reported as TIRADS 3 nodules
• The incidence of follicular variant of papillary carcinoma among TIRADS 3 lesions is 11% in our series
• Use of combined criteria of nodule in nodule sign and hypoechoic internal sepate sign will help identify malignancy in TIRADS 3 nodules.