The Terrific Thyroid (Thyroid Gland and Related Disease)CHAPTER 1

Dr Hakaru Hashimoto was born on May 5, 1881, in the village of Midau, Nishi-tsuge in the Mie prefecture, Iga-Ueno, Japan. He was born in a family that had been practicing medicine for generations whose inspiration was his grandfather, Gen'I Hashimoto who was practicing Dutch medicine.

A 2-year-old girl presented with swelling under her chin from the age of 6 months. The swelling was insidious in onset, painless and gradually progressive in size. It was not associated with any discharge or skin changes. The child did not have any intraoral complaints. A 2 cm by 1 cm firm, non-tender and mobile swelling was detected in the left submental region at level 1A. The skin over the swelling was normal and the swelling was not bi-digitally palpable. The thyroid gland was not palpable. Ultrasound of the neck was done and images are displayed below.

Laboratory test showed a normal thyroid functions. An Ultrasound scan of the neck showed an absent left lobe of the thyroid with multiple enlarged lymph nodes in level 2, 3 and 4 (Fig. 1).

Thyroid hemiagenesis is a rare embryological condition resulting from the developmental failure of one thyroid lobe. It is seen predominantly in females in a ratio of 3:1.¹ Most patients diagnosed with this disorder have an associated pathology in the remaining thyroid lobe, including benign adenoma, multinodular goiter, hyperthyroidism, chronic thyroiditis, and rarely carcinoma. The most common pathology involved in thyroid hemiagenesis is hyperthyroidism.² The molecular mechanism behind hemiagenesis of thyroid has not yet been described in detail. But, a mouse model with Shh^-/- mutation showed hemiagenesis of the thyroid or a of non-lobulated gland. Hemiagenesis was also seen in mouse model with a double heterogenous mutation of Pax8^+/- and Tif^+/+3. The presence of carcinoma in a patient with hemiagenesis is quite rare and only a few cases have been reported in the world literature.

4A young girl, 15 years of age, at present studying in 6th grade was brought by her mother for the evaluation of short stature. On clinical examination, she had a puffy face with a depressed nasal bridge. She also had dry, yellowish discolouration of skin. She was short statured and was mentally challenged (Fig. 1). Her height was less than the third centile for her age.

Thyroid scintigraphy was done (Fig. 3) and showed no tracer uptake in the neck in the region of thyroid but abnormal tracer accumulation was seen in the suprahyoid region.

Congenital hypothyroidism (CH) is one of the most common treatable causes of intellectual disability (mental retardation). Screening programs have been established in most developed and developing countries to detect and treat this disorder. Primary CH screening has been shown to be effective for the testing of cord blood or heel prick blood collected during the delivery, although the best “window” for testing is 3–5 days of age. Blood is spotted onto special filter paper (known as Guthrie cards), allowed to dry, and eluted into a buffer for TSH analysis. Normally serum TSH levels rises after birth (upto 60 µU/mL with the previous TSH assays) and falls less than 10 µU/mL after 48–72 hours. So a TSH level of upto 8–10 µU/mL can be considered as normal upto 12 week of infancy. With the newer assays TSH values are considered significant for the diagnosis of congenital hypothyroidism when it is around 20–25 µU/mL. The dose of thyroxine is as follows depending upon the age of the patient.

6A 16-year-old boy, studying in 10th grade, presented with short stature as the boy was concerned about the same was born to nonconsanguinous parents, at term, by caesarean section, with a birth weight of 2.35 kg. He had neonatal jaundice for 5 days which eventually subsided. His mother gave a history of delayed milestones and had noticed that he was lagging behind his peers in height from the age of 10 years. There was no history of headache, visual disturbance or glucocorticoid usage. His academic performance was below average.

He had a thyroid stimulating hormone (TSH) level of 750 mIU/L with low free thyroxine and total thyroxine levels. He subsequently underwent a thyroid uptake study and images are displayed above. Tc99m thyroid scan shows tracer 2 areas of uptake: at base of tongue and in the midline of the neck above the thyroid bed. It is suggestive of congenital hypothyroidism with ectopic thyroid in lingual and suprahyoid regions (see Fig. 1).

Ectopic thyroid is a rare developmental anomaly of the thyroid gland which is defined as the presence of thyroid tissue at a site other than the pretracheal area. In most cases, ectopic thyroid is located along the embryologic descent path of migration as either as a lingual thyroid or a thyroglossal duct cyst.¹ A lingual thyroid is the most common presentation of ectopic thyroid. In 70% of cases of ectopic thyroid, the normal thyroid gland is absent and this ectopic gland is the only functional thyroid tissue.² Nearly 1–3% of all ectopic thyroids are located in the lateral neck.

8A 69-year-old lady, who was known to have 2 diabetes mellitus, hypertension and coronary artery disease presented with neck swelling for a duration of 9 years (Fig. 1). The swelling was cystic in nature and was pulsatile. There was no history suggestive of either hypothyroidism or hyperthyroidism. There was no history of associated pressure related symptoms. On examination, the thyroid gland was normal in size. There was no tracheal tug and the swelling did not move up with deglutition or protrusion of the tongue. Thyroid function tests were normal.

A color Doppler of the swelling revealed dilatation of the right innominate artery, which was suggestive of an aneurysm. This swelling was mimicking a thyroid swelling (Fig. 2).

Here are some differential diagnosis for a neck mass:

Congenital Neck Mass:^1,2

Inflammatory Neck Mass:

Neoplastic Disorders:

9A 38-year-old lady presented with the history of a painless swelling in front of the neck for the past 2 years. She had history of weight gain and cold intolerance for which she approached her family physician and was started on oral replacement of thyroxine, after preliminary thyroid function tests. She also had complaints of pain in the proximal interphalangeal joints of both her hand over the past 5 years for which she had taken analgesics off and on, for pain relief.

The biochemical evaluation showed a high thyroid stimulating hormone (TSH) titre of 56 mIU/L and the thyroid peroxidase antibody titres (TPOAb) (normal-less than 35 IU/mL) were 1000 IU/mL. She also was Rheumatoid Factor (RF) positive (100 u/mL). A biopsy of the thyroid swelling showed heterogeneous clusters of lymphocytes (Fig. 3).

Hashimoto's thyroiditis is considered as an autoimmune disease whose detection was originally based on the tissue biopsy but which now can be reliably detected by the presence of high titre anti-microsomal antibodies. Its relationship to rheumatic diseases seems more frequent than might be expected, but this has not been definitely proved. Hashimoto's thyroiditis frequently leads to hypothyroidism, which in turn progresses to myxoedema. Rheumatic syndromes associated with hypothyroidism include fibrositis, myositis, myalgias, carpal tunnel syndrome, Sjögren's syndrome, joint stiffness and joint effusion. ^1,2 Thyroid dysfunction is seen at least three times more often in women with RA than in women with similar demographic features with non-inflammatory rheumatic diseases such as osteoarthritis and fibromyalgia. Most of these manifestations are said to resolve with thyroid replacement.

11A 32-year-old lady presented with intolerance to heat, significant weight loss for over a month. Over the past one week she had also developed pain over the neck, fever and tremors.

A biopsy of the thyroid gland was done which showed neutrophils and epithelioid giant cells (Fig. 2).

Inflammatory disorders of the thyroid gland are divided into three groups according to their duration: acute, subacute and chronic. De Quervain's thyroiditis (also termed giant cell or granulomatous thyroiditis) is a subacute inflammation of the thyroid, which accounts for 5% of the thyroid inflammatory disorders. The etiology is unknown, but it generally appears two weeks after an upper viral respiratory infection.

12A 21-year-old gentleman was referred to our thyroid clinic with a history of progressive proximal muscle weakness, muscle pain and fatigue after minimal exercise. He complained of swelling of the calf muscles over the past few years and constipation.

Laboratory tests including muscle biopsy showed features of rhabdomyolysis (Fig. 2), creatinine phosphokinase (CPK) 1500 U/L (25-90 U/L).

Myopathic changes are seen in 30–80% of patients with hypothyroidism. There are four variants of hypothyroid myopathy which are Hoffmann's syndrome, Kocher-Debre-Semelaigne syndrome, an atrophic form and a myasthenic syndrome. Hoffmann's syndrome was first described by Johann Hoffmann in 1897.

Electrophysiological studies may show myogenic, neurogenic or mixed patterns in hypothyroid myopathy. Biopsy of the affected muscles may show muscle fibre necrosis, atrophy, hypertrophy with increased number of nuclei and increased connective tissue (Fig. 2).

The milky white serum was seen due to elevated serum triglyceride levels (1800 mg/dL). In primary hypothyroidism there is a reduction in activity of lipoprotein lipase which then in turn causes hypertriglyceridemia. The mechanism of hypercholesterolemia is explained by a reduction in LDL-cholesterol hepatic receptor activity due to hypothyroidism.

14A 30-year-old lady presented to the outpatient department with a swelling in front of the neck, hoarseness of voice, fatigue and progressive worsening muscle weakness. She had a significant weight loss of 5 kg over 6 months. She also complained of difficulty in chewing wheat pancakes, but no such symptoms with soft solids. She also gave a history of 2 episodes of sudden onset breathing difficulty in the past requiring invasive ventilation and subsequent tracheotomies. At presentation sequential photographs were taken and show the following clinical findings (Fig. 1).

Her blood investigations showed TSH of 0.007, FTC of 2.2 and a T4 of 21.2. Anti-acetylcholine receptor antibody was 0.56 (normal < 2.1), anti-thyroglobulin antibodies: 22 (< 100 IU/mL), anti-microsomal (thyroid peroxidise) 400 (< 50 IU/mL). A CT scan of the neck was done and had shown an enlarged thyroid gland with a bulky thymus inconsistent for her age (Fig. 2).

This patient has a classical history suggestive of autoimmune hyperthyroidism with myasthenia gravis.

It is well known that autoimmune thyroid disorders are known to be present only in 5–7.5% of the myasthenia gravis (MG) patients. However Myasthenia is seen in only 0.2% of the patients with thyroid disease.¹ The higher frequency of ocular myasthenia in autoimmune thyroid disease could well be attributed to the genetic linkage. Certain Human leukocyte antigen (HLA) specificity (B8, DR3, and BW46) between MG and thyroid disease has been reported to be associated with thyrotoxicosis.²

15A 19-year-old girl had early satiety towards the evening, tremors and weight loss and underwent radioactive l¹³¹ ablation two years ago. She presented now with weight gain, yellowish tinged skin and hoarseness of voice (Fig. 1). On examination she was found to have bilateral ptosis with easy fatigability after talking for 2 minutes.

Her thyroid stimulating hormone (TSH) before ablative treatment was <0.01 mIU/mL and FTC was 10 ng/dL. Pre-ablation iodine uptake studies (I₁₃₁) showed enlarged thyroid gland (both lobes) with uniform tracer uptake (Fig. 2).

Graves' disease and myasthenia gravis are both autoimmune diseases and the coexistence of these two diseases is rare but well recognized. Epidemiological studies have shown that autoimmune thyroid disease (AITD) occurs in approximately 5–10% of patients with myasthenia gravis (MG), whereas MG is reported in a fairly low frequency (0.2%) of patients with AITD.¹ The association is thought to be uncommon, and it is generally believed that hyperthyroidism is far more commonly associated with MG than is hypothyroidism. However, no explanation has been offered to account for this difference.

Adrenal failure may precede other endocrinopathies. Vitiligo and gonadal failure are occasionally associated with PAS type II than with type I. The other disorders like immunogastritis, pernicious anemia, and alopecia areata may occur in PAS type II. Immunogastritis, eventually leading to pernicious anemia, is an organ-specific autoimmune disease. PAS type II is believed to be polygenic, characterized by an autosomal dominant inheritance.²

17A 12-year-old boy presented with hair loss, a small thyroid swelling, lethargy and drooping of eyelids as shown in Figures 1A and B. His thyroid stimulating hormone (TSH) was 12.0 mIU/L.

This patient was diagnosed to have autoimmune thyroid disease-Hashimotos thyroiditis with Myasthenia gravis and alopecia, suggestive of Type 2 Autoimmune Polyglandular Endocrinopathy syndrome.

Graves' disease and myasthenia gravis are both auto-immune diseases and the coexistence of these two diseases is rare but well recognized. Epidemiological studies have shown that autoimmune thyroid disease (AITD) occurs in approximately 5–10% of patients with myasthenia gravis (MG), whereas MG is reported in a fairly low frequency (0.2%) of patients with AITD.¹ The association is thought to be uncommon, and it is generally believed that hyperthyroidism is far more commonly associated with MG than is hypothyroidism. However, no explanation has been offered to account for this difference.

18A 65-year-old lady who is a known patient of Graves' disease presented to the Thyroid specialty clinic with a history of redness of eyes.

This patient had an active eye disease due to Graves' ophthalmopathy (GO) with a clinical activity score (CAS) of 4/7 (Figs. 1A and B).

For initial clinical activity score (CAS), only items 1–7 are scored.

A 29-year-old lady presented with history of menorrhagia and progressive weight gain and tiredness. The patient was looking dull and on examination was found to have dry and scaly skin (Figs. 10A and B and Fig. 12). The clinical pictures of the upper limb are shown below.

Histopathologically, pretibial myxedema shows deposition of mucin (glycosaminoglycans) throughout the dermis and subcutis. Deposited mucin promotes dermal oedema by promoting the retention of fluid in the skin. This results in compression/occlusion of small peripheral lymphatics and lymphoedema. There are 4 typical types seen:

24A 43-year-old lady presented to the Endocrinology clinic with complaints of swelling in the right side of the neck, which was slowly increasing in size over the past 3 years.

This patient has a cystic nodule in the right lobe of thyroid which explains the regression of the thyroid nodule after the FNAC. The differential diagnosis in this patient is a cystic parathyroid adenoma. Thyroid scintigraphy showed a hypofunctioning “cold” nodule, as these cystic nodules do not concentrate radioiodine or technetium. Aspiration cytology in this patient showed only colloid (Figs. 2 and 3).

The majority of cystic thyroid nodules are benign degenerating thyroid adenomas. Autonomously functioning thyroid adenomas are more likely to undergo cystic degeneration than nonfunctioning adenomas. Purely cystic lesions rarely contain cancer.¹ Size (> 4 cm) of the cystic nodule may also be used as a criterion for surgery, although we do not use size as an absolute criteria for surgery.²

25A 43-year-old gentleman presented with headache of 3 years duration, failure to gain height from the age of 8 years, underdeveloped secondary sexual characteristics and mental retardation.

The presence of short stature, with a mentally challenged state, led to the clinical suspicion of congenital hypothyroidism. His I¹³¹ uptake study was 0.3% which was grossly reduced, thereby suggestive of thyroid hypoplasia and confirmed the diagnosis.

Congenital hypothyroidism (CH) is a common preventable cause of a mentally challenged state. The estimated incidence in India is 1:2500–2800 live births with a varied age of onset and clinical features.¹ Much of the etiology is due to thyroid ectopia, aplasia or hypoplasia. Disturbances of growth, puberty, and sexual function in those with CH as seen in our subject can be explained by the secondary effects of thyroid hormone deficiency on pituitary function.² Severe protracted thyroid hormone deficiency may therefore result in thyrotrophin adenomas of the pituitary gland.

27A 36-year-old gentleman presented with holocranial headache for over 2 months and weight gain of 10 kg in 5 months. He had a dull look with slow relaxation of the ankle joint reflexes. He did not have vomiting or postural hypotension (Fig. 1).

With the above clinical and investigative findings he was diagnosed to have primary hypothyroidism with pituitary pseudotumor.

Pituitary pseudotumor (pituitary thyrotroph hyperplasia) caused by unrecognized and untreated hypothyroidism has been described mostly in adults. Treatment with levothyroxine results in normalization of the size of the pituitary gland.¹ The myolysis in hypothyroid patients are caused by the change of fast twitching type 2 muscle fibre to slow twitching type 1 muscle fibre, deposition of glycosaminoglycan, poor contractility of the actin-myosin filaments, low myosin ATPase activity and low ATP turnover. This is associated with elevated CPK levels which usually subside after levothyroxine treatment.²

28A 34-year-old lady presented with a swelling in front of the neck for 2 years duration (Fig. 1). There were no symptoms of thyroid dysfunction or compressive symptoms (dysphagia, dyspnea or hoarsness of voice). There was no significant past history or family history.

Ultrasound showed a well defined, solid, isoechoic nodule with positive halo sign (thin hypoechoic rim around the lesion) in the right lobe of thyroid. These are features of probably benign thyroid nodule. There were other small colloid nodules in both lobes. A radionuclide scan was done and revealed a cold nodule in the right lobe (Fig. 3). Thus, dominant nodule in a multinodular goitre is the most likely diagnosis.

Nodularity of thyroid tissue is extremely common. In a large population study (Framingham, MA), as an example, clinically apparent thyroid nodules were present in 6.4 percent of women and 1.5 percent of men.

30A 72-year-old, Mrs. E from Meghalaya was seen in the endocrinology OPD with a history of swelling in front of the neck for 50 years. She had been operated in 1972, with a probable subtotal thyroidectomy, for the swelling. Ten years after the surgery, she noticed a similar neck swelling, which had gradually progressed to the present size (Figs. 1A and B). She had symptoms of dyspnea and hoarseness of voice. She also complained of dysphagia. There were no other symptoms suggestive of hyperthyroidism or hypothyroidism.

Fine needle aspiration (FNA) smears from the right thyroid nodule were suggestive of benign follicular nodule. In view of the large thyroid mass and compressive symptoms, she underwent total thyroidectomy. The surgical specimen on examination showed features of nodular hyperplasia. So the diagnosis of recurrent symptomatic benign nodular hyperplasia of thyroid was made. She was advised total thyroidectomy inview of the size and compressive symptoms.

Nodularity of thyroid tissue is extremely common. In a large population study (Framingham, MA), as an example, clinically apparent thyroid nodules were present in 6.4 percent of women and 1.5 percent of men.

33A 72-year-old lady, presented with the history of low backache which had worsened over the past ten days and a progressively increasing neck swelling for the past 2 years. Previously, she had undergone a right hemi-thyroidectomy in 1990 for a solitary thyroid nodule.

Magnetic resonance imaging (MRI) of the spine (Figs. 2A to C) was done and it showed a sacral mass which was suggestive of metastasis. A whole body iodine uptake scan was done and showed similar evidence of sacral metastasis.

Papillary thyroid carcinoma is well-differentiated and slow growing, and have unique characteristics. Adjuvant therapy includes thyroid hormone suppression and radioiodine (¹³¹I) therapy rather than chemotherapy and radiotherapy. The prognosis is generally excellent and is influenced by factors related to the patient, the disease and the therapy. Factors associated with a less favorable outcome are male sex, age >40 years, family history of papillary cancer, tumor diameter >4 cm, lymph node or distant metastases and invasive nature or poorly differentiated tumor. After total thyroidectomy and ¹³¹I ablation, the follow-up includes a diagnostic radioiodine scan and serum thyroglobulin estimation (after thyroxine withdrawal) at six months. Further long term follow-up includes clinical examination, TSH monitoring to ensure adequate suppression and serum thyroglobulin measurement.¹ If thyroglobulin becomes detectable in a patient taking thyroxine then thyroxine is withdrawn, a diagnostic whole body scan is performed and the thyroglobulin measurement is repeated. Recombinant human TSH administration can be used to avoid the need for thyroxine withdrawal.²

37A 54-year-old Mr. G was seen in the Endocrinology OPD with history of progressive swelling in neck for 5 years, associated with history of pain in neck. He was clinically and biochemically euthyroid. He had no other compressive symptoms. On examination, there was a 6 × 5 cm firm to hard swelling more on the left than the right side, which moved up with deglutition. The trachea was deviated to the right. Computed tomography (CT) scan of the neck is shown in Figures 1 and 2. He underwent a total thyroidectomy and the specimen were sent for histopathological examination (Figs. 3 and 4).

The surgical specimen was evaluated and was found to have multifocal classical papillary thyroid carcinoma.

Mr G was evaluated for rapidly progressing paraparesis. A MRI spine showed features of skeletal metastases in multiple vertebrae. First thoracic vertebra showed collapse and epidural component causing cord compression (Fig. 6). A CT scan of the thorax also revealed multiple nodules in both the lungs (Fig. 8). He was planned for palliative radiotherapy to the spine. He was also referred to the spine surgery department for urgent decompressive surgery.

A 61-year-old, Mrs S presented to the casualty with history of slip and fall in the bathroom and sustained a closed injury to her left thigh. She had undergone a total thyroidectomy and Sistrunk's operation few months earlier. On examination she had swelling and tenderness over the left thigh with an abnormal mobility and crepitus. The X-ray of the left femur is shown below.

Mrs S was diagnosed to have papillary carcinoma thyroid who underwent a total thyroidectomy elsewhere came to our centre for further management. She developed a pathological fracture of the left femur and she underwent intramedullary nailing and fixation for the same (Fig. 1). The histopathology from the left femur was reported as metastatic adenocarcinoma and the thyroid pathology slides reviewed was reported as classical papillary carcinoma thyroid. Chest X-ray and Computed tomography (CT) thorax revealed features of metastasis (Figs. 2A and B). Computed tomography (CT) abdomen showed a metastasis in the vertebrae (Fig. 3). The I₁₃₁whole body scan showed an increased uptake in the thyroid residue (Fig. 4).

The overall incidence for papillary thyroid cancer (PTC) is 16.3/100,000 for women and 5.6/100,000 for men.

A history of rapid growth, a thyroid nodule or fixation of the nodule to surrounding tissues, and compressive symptoms like new onset hoarseness or vocal cord paralysis, dysphagia or dyspnea or the presence of ipsilateral cervical lymphadenopathy should raise the suspicion that a nodule may be malignant. Risk factors for PTC include a history of radiation exposure during childhood, a history of thyroid cancer in a first-degree relative, or a family history of a thyroid cancer.¹

47A 75-year-old lady, presented with a progressive swelling in front of the neck for 30 years. There was no history of hyperthyroidism or hypothyroidism. There were no pressure symptoms like dysphagia or hoarseness of voice. She complained of a choking feeling for the past 2 years, when she lies flat. Her husband and three of her children were taking medicines for hypothyroidism. On examination, she had a 10 × 8 cm size, firm swelling in front of the neck which was more on the right side, which moved up with deglutition. There was no retrosternal extension but the trachea was deviated to left side.

The diagnosis was that of a dominant nodule in a multinodular goitre. The patient underwent a total thyroidectomy and the surgical specimen was diagnosed to be a follicular variant of papillary carcinoma involving left lobe. Hurthle cell nodules were also evident in the left lobe. Post surgery she was put on suppressive doses of thyroxine.

The overall incidence for papillary thyroid cancer (PTC) is 16.3/100,000 for women and 5.6/100,000 for men. A history of rapid growth, a thyroid nodule or fixation of the nodule to surrounding tissues, and compressive symptoms like new onset hoarseness or vocal cord paralysis, dysphagia or dyspnea or the presence of ipsilateral cervical lymphadenopathy should raise the suspicion that a nodule may be malignant. Risk factors for PTC include a history of radiation exposure during childhood, a history of thyroid cancer in a first-degree relative, or a family history of a thyroid cancer.¹

49A 60-year-old lady presented with swellings on head for the past 2 years and in front of her neck for the past 6 years. (Fig. 1)

On further history she had symptoms of hypothyroidism (lethargy, tiredness) and complained of pain in the swelling of the head. She also complained of lower back ache.

Follicular thyroid cancer is the second most common type of thyroid cancer after papillary thyroid cancer.¹ Follicular thyroid cancer typically spreads via hematogeneous dissemination. Common sites of distant metastases are bone (with lytic lesions) and lung and, less commonly, the brain, liver, bladder, and skin. Unlike papillary thyroid cancer, FNA biopsy cannot diagnose or distinguish between the follicular adenomas and cancers. Microscopically, the diagnosis of follicular cancer requires distinguishing 50adenoma from cancer, through identification of tumor extension through the tumor capsule and/or vascular invasion, given the fact that follicular cancer commonly occurs in older patients and is more often associated with an aggressive clinical course and distant metastases.

It has higher mortality than papillary thyroid cancer.²

51A 48-year-old lady presented to our clinic with a history of progressive, painless swelling in front of the neck over the past 25 years. However, more recently, she had developed dyspnea on exertion with hoarseness of her voice. She was not a hypertensive and did not have any associated skin lesions.

Based on the clinical, pathological and radiological findings she was diagnosed with medullary thyroid carcinoma with tracheal invasion.

Medullary thyroid carcinoma (MTC) is an uncommon neuroendocrine malignancy that accounts for 5% of all the thyroid cancers.¹ Medullary thyroid carcinoma (MTC) presents in sporadic and familial forms (multiple endocrine neoplasia (MEN) 2A, MEN 2B, or familial MTC syndromes). The familial forms are secondary to germline mutations in the REarranged during Transfection (RET) proto-oncogene. Early diagnosis and treatment is most important. Genetic testing has made possible, the early detection in asymptomatic carriers and high-risk patients, with early or prophylactic surgery being curative in many. All carriers of an RET mutation should be evaluated and treated surgically for MTC. The primary treatment in all patients diagnosed with MTC is total thyroidectomy with central lymph node dissection.²

53A 34-year-old lady presented with an insidious onset and slowly progressive neck swelling for over 12 years. She did not have features suggestive of either hypothyroidism or hyperthyroidism. There was no previous history of pressure symptoms.

Figures 2A and B could represent malignancy in a thyroglossal cyst. Subsequently, she underwent FNA cytology which showed clusters of colloid and psammoma bodies with occasional follicular cells suggestive of Papillary carcinoma thyroid in a thyroglossal cyst (Fig. 3).

The thyroglossal duct cyst (TGDC) is the most common anomaly associated with thyroid development. The thyroid gland descends from the foramen caecum to a point below the thyroid cartilage and leaves an epithelial tract known as the thyroglossal tract. The tract disappears during the 5th to the 10th gestational week. Incomplete atrophy of the tract forms the basis of origin of the cyst.¹

55A 56-year-old non-smoking farmer presented to our Thyroid clinic with the rapid progression of the thyroid swelling over the past 20 days with simultaneous hoarseness of voice during the same period. He had a thyroid swelling for the past 20 years whose size was static in nature (Fig. 1).

This gentleman had probable anaplastic carcinoma clinically in view of the rapid progression of the symptoms. The hoarseness of voice could be well due to the external laryngeal nerve involvement. The Chest X-ray showed a massive deviation of trachea to the left side.

Anaplastic thyroid cancers are undifferentiated tumors of the thyroid follicular epithelium. In marked contrast to the differentiated thyroid cancers, anaplastic cancers are extremely aggressive, with a disease-specific mortality approaching 95 percent. The few exceptions are patients whose tumors are small and who are treated very aggressively. Approximately 20 percent of patients have a history 56of differentiated thyroid cancer and 20–30 percent have a coexisting differentiated cancer.

The primary symptom of anaplastic cancer is a rapidly enlarging neck mass, occurring in about 85 percent of patients.¹

57A 46-year-old lady presented to us with complaints of multiple swellings in front of the neck for a period of 4 years. There were no specific symptoms of thyroid disturbances but she complained of difficulty in swallowing. There were complaints of change in voice.

This patient most likely had a malignant thyroid swelling with nodular metastasis. A fine needle aspiration cytology (FNAC) should be done to confirm the diagnosis.

Ultrasound of the thyroid is done with high frequency (7 to 13 MHz) transducers. Ultrasonography is highly operator dependent. It is done for detection of non palpable nodules, characterization of nodule, therapeutic purposes and for monitoring of nodule size. The risk of malignancy with respect to the echogenecity are:

This works on the principle of differential uptake of radioactive isotopes. Risk of malignancy is:

The patient was diagnosed to have a malignancy in the thyroid swelling. There is an increased risk of malignancy in swellings that are ‘cold’ on radionuclide scanning.

The patient has a hot nodule (Fig. 22, shown with circle) and the risk of malignancy in such nodules is low ~<1%.