Solitary Thyroid Nodule Flashcards
describe the prevalence of solitary thyroid nodules
common, occur in around 5% of women
what % of solitary thyroid nodules are benign or malignant
benign = 95% malignant = 5%
what different types of benign solitary thyroid nodules are there
cyst, colloid nodule, benign follicular adenoma, hyperplastic nodule
what different types of malignant solitary thyroid nodule are there
papillary thyroid carcinoma(85%), follicular thyroid carcinoma(10%), medullary thyroid carcinoma(3%), lymphoma(<5%) or anaplastic/poorly differentiated
what is the most common type of malignant solitary thyroid nodule
papillary thyroid carcinoma(85%)
what questions should be asked to determine if it is the thyroid
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)
what should be looked out for in the history taking of a patient with a solitary thyroid nodule
any FH of thyroid cancer, neck irradiation,
what should be checked for on examination and investigation of a solitary thyroid nodule
examination = neck nodes, hoarseness investigation = TSH, USS-FNA, excision biopsy of lymph node
what is USS-FNA
Ultrasound-fine needle aspiration
what classification system is used for solitary thyroid nodules
FNA Bethesda classification, Thy 1-5
(Thy; 1 = inadequate, 2= benign, 3= atypical, 4=probs malignant, 5= malignant
describe what a low risk solitary thyroid nodule condition is
<50, tumour <4cm(ie T <3 on TNM)
describe what a high risk solitary thyroid nodule condition is
T3 or greater on TNM(ie tumour >4cm)
what treatment is used for low risk solitary thyroid nodules
low risk = lobectomy, keep TSH low level of normal, baseline thyroglobulin
what treatment is used for high risk solitary thyroid nodules
high risk = total thyroidectomy, TSH<1, thyroglobulin measurement, high dose radioiodine?
what other classification system can be used for thyroid tumours, and can be adapted and used for many types of tumour
TNM classification
describe the follow up TSH and thyroglobulin management for papillary and follicular thyroid carcinomas
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)
what are the characteristics of papillary thyroid carcinoma
occurs in younger people, local(sometimes lung/bone secondary), good prognosis, tends to spread in lymphatics rather than haematogenous
what are the characteristics of follicular thyroid carcinoma
more common in females, metastases to lung/bone(haematogenous spread), prognosis good if resectable
what are the characteristics of medullary cell carcinoma
often familial, local + metastases, poor prognosis but indolent course
(very rare)
what are the characteristics of anaplastic thyroid malignancy
aggressive, locally invasive, very poor prognosis
what can you not tell from an USS-FNA
capsular invasion
what is the biggest risk factor for thyroid lymphoma
history of autoimmune hypothyroidism
ie Hashimoto’s thyroiditis
what treatment is used for thyroid lymphomas
steroids, R-CHOP chemotherapy, radiotherapy
what does differentiated thyroid cancer(DTC) refer to
papillary and follicular variants, ‘differentiated’ means good prognosis compared to others, refers to both histology and physiology of tumour
what do differentiated thyroid cancers(DTC) take up and what do they secrete
take up iodine(and therefore radioiodine) and secrete TSH
what do the majority of DTC patients present with
palpable nodules at thyroid
