L2: Simple Goiter Flashcards
1
Q
Normally → Thyroid gland is …….
A
impalpable
2
Q
If there is Swelling/Enlargement of the thyroid gland, it may be maybe..
A
3
Q
Classifications of thyroid enlargement
A
- Simple (Euthyroid)
- Toxic
- Neoplastic
- Inflammatory
4
Q
Simple (euthyroid) thyroid enlargment
A
- Diffuse hyperplastic
- Colloid goiter
- Nodular goiter (Multinodular).
- Solitary nontoxic nodule.
- Recurrent nontoxic nodule.
- Wolff-Chaikoff effect
- Hokkaido goiter
5
Q
Causes of Diffuse hyperplastic thyroid enlargment
A
6
Q
Wolff-Chaikoff effect
A
- Intake of large quantity of iodides → inhibits the further release of thyroid hormones (inhibits organification) by autoregulatory mechanism.
- But later: may cause escape phenomenon.
7
Q
Hokkaido goiter
A
Hokkaido is a northern island in Japan where iodine-rich seaweeds are the main diet intake causes goiter in these individuals
8
Q
Toxic Thyroid Enlargment
A
9
Q
Neoplastic Thyroid Enlargment
A
10
Q
Inflammatory Thyroid Enlargment
A
11
Q
Etiology of Simple Goiter
A
12
Q
TSH is not the only stimulus to thyroid follicular cell proliferation
A
..
13
Q
Causes of lodine deficiency
A
14
Q
- Calcium is also goitrogenic.
- Goiter is common in low-iodine areas on chalk or limestone.
- Dietary deficiency of iodine is the most important factor in endemic goiter.
A
..
15
Q
Dyshormonogenesis
A
16
Q
Examples of goitrogens
A
17
Q
How do goitrogens act?
- Thiocyanates & perchlorates
A
interfere with iodide trapping.
18
Q
How do goitrogens act?
- Carbimazole & thiouracil compounds
A
interfere with:
* Oxidation of iodide
* Binding of iodine to tyrosine.
19
Q
How do goitrogens act?
- lodides in large quantities
A
- inhibit organic binding of iodine and produce an iodide goiter
20
Q
Excessive iodine intake may be associated with increased incidence of autoimmune thyroid disease
A
..
21
Q
Stages of goiter formation
(The natural history of simple goiter)
A
- Formation of Diffuse hyperplastic goiter
- Formation of nodular goiter
22
Q
Formation of Diffuse hyperplastic goiter
A
23
Q
Formation of nodular goiter
A
24
Q
- Most nodules are inactive.
- Active follicles are present only in the internodular tissue.
- The heterogeneous structural & functional response in the thyroid resulting in characteristic nodularity may be due to Presence of clones of cells particularly sensitive to growth stimulation.
A
..
25
Types of Simple Goiter
- Diffuse Hyperplastic Goiter
- Nodular Goiter
26
Pathogenesis of Diffuse Hyperplastic Goiter
- Diffuse hyperplasia corresponds to the first stages of the natural history.
27
Epidemeology of Diffuse Hyperplastic Goiter
28
CP of Diffuse Hyperplastic Goiter
29
Fate of Diffuse Hyperplastic Goiter
30
Pathogenesis of Nodular Goiter
31
Types of Nodular Goiter
32
Epidemeology of Nodular Goiter
33
Pathology of Nodular Goiter
- Nodules may be Colloid or cellular.
- Cystic degeneration & hemorrhage are common, as is subsequent calcification.
34
CP of Nodular Goiter
35
Suspicion of carcinoma in Nodular Goiter if ......
36
DDx of Nodular Goiter
Autoimmune thyroiditis.
- Differential diagnosis may be difficult & the two conditions frequently coexist.
37
Investigations for Nodular Goiter
- Thyroid function test & thyroid
Antibodies
- Ultrasonography
- Fine Needle Aspiration Cytology [FNAC]
- Plain radiographs [X-rays]
- CT
38
Thyroid Function Tests & Thyroid Abs in Nodular Goiter
To Differentiate it from thyroiditis.
39
US in Nodular Goiter
The gold standard assessment when undertaken by a suitably trained and experienced operator
40
FNAC in Nodular Goiter
41
Plain Radiographs (X-Ray) in Nodular Goiter
X-Ray of the chest and thoracic inlet
42
CT in Nodular Goiter
CT neck & chest:
- It's the best modality to assess Tracheal or esophageal deviation or compression, if there are swallowing or breathing symptoms.
43
Complications of Multinodular goiter
44
Lines of treatment of simple goiter
45
How to deal with Endemic goiter?
Introduction of iodized salt, In endemic areas
46
How to deal with Hyperplastic Goiter?
In the early stages, a hyperplastic goiter may regress if thyroxine is given in a dose of 0.15-0.2 mg daily for a few months.
47
How to deal with multinodular Goiter?
Most patients with multinodular goiter are asymptomatic & do not require operation, except:
1. Cosmetic grounds
2. Pressure symptoms
3. As response to patient anxiety.
4. Retrosternal extension with tracheal compression
5. Presence of a dominant area of enlargement that may be neoplastic.
48
Incidence of **Clinically Discrete Swellings**
- Common condition.
- Sex: in women > men (by 3 to 4 times).
49
Etiology of **Clinically Discrete Swellings**
50
Dx of **Clinically Discrete Swellings**
51
The importance of discrete swellings: lies in the risk of neoplasia compared with other thyroid swellings.
- 15% of isolated swellings prove to be malignant.
..
52
Investigations for **Clinically Discrete Swellings**
- Thyroid Function Tests
- Autoantibody Titers
- Isotope Scan
- US
- FNAC
- Radiology
- Laryngoscope
- Core Biopsy
53
Thyroid Function Tests in **Clinically Discrete Swellings**
54
Antibody Titers in **Clinically Discrete Swellings**
55
Importance of Isotope Scan in **Clinically Discrete Swellings**
It's the mainstay of investigation to determine the functional activity relative to the surrounding gland according to isotope uptake.
56
Routine isotope scanning has been abandoned except when
toxicity is associated with nodularity.
57
On scanning, swellings are categorized as
58
Importance of US in **Clinically Discrete Swellings**
1. Can demonstrate subclinical nodularity and cyst formation.
2. Also used for FNAC.
59
US findings in thyroid swelling suggestive of neoplasia
1. Microcalcifications
2. Increased vascularity by doppler.
3. Only macroscopic capsule breach & nodal involvement are diagnostic of malignancy.
60
How to use FNAC in **Clinically Discrete Swellings**?
FNAC should be used, ideally under ultrasound guidance.
61
When to Use FNAC in **Clinically Discrete Swellings**?
on all nodules that do not fulfill a fully benign (U2) classification on ultrasonography.
62
Advantages of FNAC in **Clinically Discrete Swellings**
63
FNAC Can Diagnose .....
64
Disadvantages of FNAC in **Clinically Discrete Swellings**
65
FNAC cannot distinguish between a benign follicular adenoma & follicular carcinoma, Why?
This distinction is dependent not on cytology but on histological criteria, which include capsular & vascular invasion.
66
Radiology in **Clinically Discrete Swellings**
67
Chest & thoracic inlet radiographs in **Clinically Discrete Swellings**
68
CT & MRI scans in **Clinically Discrete Swellings**
69
PET CT scan in **Clinically Discrete Swellings**
May be useful in:
- Localizing disease which does not uptake radioiodine.
70
Flexible laryngoscopy has rendered indirect laryngoscopy obsolete.
..
71
Importance of Laryngoscope in **Clinically Discrete Swellings**
1. Medicolegally: is widely used preoperatively to determine the mobility of the vocal cords for medicolegal rather than clinical reasons.
2. In Diagnosis of malignant disease: The presence of a unilateral cord palsy with a swelling suggestive of malignancy is usually diagnostic.
72
In Diagnosis of malignant disease: The presence of a unilateral cord palsy with a swelling suggestive of .......
Malignancy
73
Core Biopsy in **Clinically Discrete Swellings**
74
How To Deal With Nontoxic benign nodule?
- Treated with observation without any therapy.
- Follow up with: annual clinical examination & ultrasound neck.
75
How To Deal With Solitary toxic nodule?
1. Initially → antithyroid drugs.
2. Then → Radioactive iodine therapy.
76
How To Deal With Colloid nodule?
1. Can be observed.
OR
2. Hemithyroidectomy → Done for cosmosis.
77
How To Deal With Papillary carcinoma of thyroid?
- Then, Total or near total thyroidectomy with or without radioactive iodine & hormonal replacement.
78
How To Deal With Follicular adenoma?
-Then, Hemithyroidectomy
- Then, Total thyroidectomy → if found malignant pathologically.
79
How To Deal With Medullary carcinoma of thyroid?
- Then, Total thyroidectomy with bilateral neck nodal dissection including central compartment.
80
Indications of surgery in **Clinically Discrete Swellings**
81
There are useful clinical criteria to assist in selection for operation according to the risk of neoplasia and malignancy:
82
Epidemeology of Thyroid Neoplasia
83
Def of **Retrosternal Goiter**
84
Etiology of **Retrosternal Goiter**
85
Types of **Retrosternal Goiter**
86
Symptoms of **Retrosternal Goiter**
87
Signs of **Retrosternal Goiter**
88
Investigations in **Retrosternal Goiter**
89
X-Ray in **Retrosternal Goiter**
90
CT Scan in **Retrosternal Goiter**
91
TTT of **Retrosternal Goiter**
92
Def of **Thyroid Incidentaloma**
Clinically unsuspected and impalpable thyroid swellings.
93
Managment of **Thyroid Incidentaloma**
The majority of impalpable thyroid swellings can be safely managed by a single annual review, with no intervention unless:
A. Certain criteria are met.
B. OR the swelling becomes palpable.
94
Def of **Thyroid Cyst**
Thyroid swelling which is cystic in nature & elicit positive fluctuation.
95
Etiology of **Thyroid Cyst**
96
Managment of **Thyroid Cyst**
97
Breathing difficulties in thyroid swelling
