Transcript Audit of TIRADS III nodules

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
Objectives
1.
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
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
Total no. of USG thyroids = 670
TIRADS III nodules
n = 102
With HPE= 51
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%
Surgical Histopathology: ( n=18)
Total no= 51
Follicular variant papillary
carcinoma thyroid
No
11
Percentage %
61
Adenomatous hyperplasia
04
22
Follicular adenoma
02
11
No follicular hyperplasia
01
6
All malignant nodules (n=11) were encapsulated variety of
follicular variant of papillary carcinoma thyroid.
Bethesda classification cytology (FNAC):
n=41
Bethesda No. of %
class
cases
class II= 34
35
30
I
01
1.9
25
II
34
66.6
20
III
03
5.8
15
10
IV
V
03
00
5.8
00
5
class I = 1
0
class I
VI
00
00
class III= 3
class II
class IV =3
class V, 0
class III
class IV
n=41
class VI, 0
class V
class VI
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 criteria
Diagnostic performance
Sensitivity
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.
37 year old female -Case of follicular variant of papillary carcinoma
Eccentric hypoechoic focus within a isoechoic well defined
nodule - positive nodule in nodule sign
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
54 year old man with histopathology
diagnosis of follicular variant of papillary
carcinoma
Well defined isoechic hetrogenous nodule
-positive for nodule within nodule sign
-positive for hypoechoic internal septae sign
-positive thick non uniform halo
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
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.