Solitary Thyroid Nodule

Question 1

describe the prevalence of solitary thyroid nodules

Answer 1

common, occur in around 5% of women

Question 2

what % of solitary thyroid nodules are benign or malignant

Answer 2

benign = 95%
malignant = 5%

Question 3

what different types of benign solitary thyroid nodules are there

Answer 3

cyst, colloid nodule, benign follicular adenoma, hyperplastic nodule

Question 4

what different types of malignant solitary thyroid nodule are there

Answer 4

papillary thyroid carcinoma(85%), follicular thyroid carcinoma(10%), medullary thyroid carcinoma(3%), lymphoma(<5%) or anaplastic/poorly differentiated

Question 5

what is the most common type of malignant solitary thyroid nodule

Answer 5

papillary thyroid carcinoma(85%)

Question 6

what questions should be asked to determine if it is the thyroid

Answer 6

does it move on swallowing?, is it invested in the pre-tracheal fascia? is it painful?(uncommon feature of nodule usually caused by intrathyroidal bleed into cyst)

Question 7

what should be looked out for in the history taking of a patient with a solitary thyroid nodule

Answer 7

any FH of thyroid cancer, neck irradiation,

Question 8

what should be checked for on examination and investigation of a solitary thyroid nodule

Answer 8

examination = neck nodes, hoarseness
investigation = TSH, USS-FNA, excision biopsy of lymph node

Question 9

what is USS-FNA

Answer 9

Ultrasound-fine needle aspiration

Question 10

what classification system is used for solitary thyroid nodules

Answer 10

FNA Bethesda classification, Thy 1-5

(Thy; 1 = inadequate, 2= benign, 3= atypical, 4=probs malignant, 5= malignant

Question 11

describe what a low risk solitary thyroid nodule condition is

Answer 11

<50, tumour <4cm(ie T <3 on TNM)

Question 12

describe what a high risk solitary thyroid nodule condition is

Answer 12

T3 or greater on TNM(ie tumour >4cm)

Question 13

what treatment is used for low risk solitary thyroid nodules

Answer 13

low risk = lobectomy, keep TSH low level of normal, baseline thyroglobulin

Question 14

what treatment is used for high risk solitary thyroid nodules

Answer 14

high risk = total thyroidectomy, TSH<1, thyroglobulin measurement, high dose radioiodine?

Question 15

what other classification system can be used for thyroid tumours, and can be adapted and used for many types of tumour

Answer 15

TNM classification

Question 16

describe the follow up TSH and thyroglobulin management for papillary and follicular thyroid carcinomas

Answer 16

TSH lower end of normal(0.4-4), use thyroglobulin for tumour cell marker, Measure both every 6 months for 5 years then annually for 5 years
(consider discharge after 5 years if low risk)

Question 17

what are the characteristics of papillary thyroid carcinoma

Answer 17

occurs in younger people, local(sometimes lung/bone secondary), good prognosis, tends to spread in lymphatics rather than haematogenous

Question 18

what are the characteristics of follicular thyroid carcinoma

Answer 18

more common in females, metastases to lung/bone(haematogenous spread), prognosis good if resectable

Question 19

what are the characteristics of medullary cell carcinoma

Answer 19

often familial, local + metastases, poor prognosis but indolent course
(very rare)

Question 20

what are the characteristics of anaplastic thyroid malignancy

Answer 20

aggressive, locally invasive, very poor prognosis

Question 21

what can you not tell from an USS-FNA

Answer 21

capsular invasion

Question 22

what is the biggest risk factor for thyroid lymphoma

Answer 22

history of autoimmune hypothyroidism

ie Hashimoto’s thyroiditis

Question 23

what treatment is used for thyroid lymphomas

Answer 23

steroids, R-CHOP chemotherapy, radiotherapy

Question 24

what does differentiated thyroid cancer(DTC) refer to

Answer 24

papillary and follicular variants, ‘differentiated’ means good prognosis compared to others, refers to both histology and physiology of tumour

Question 25

what do differentiated thyroid cancers(DTC) take up and what do they secrete

Answer 25

take up iodine(and therefore radioiodine) and secrete TSH

Question 26

what do the majority of DTC patients present with

Answer 26

palpable nodules at thyroid