Thyroid malignancies are divided into papillary carcinomas (80%), follicular carcinomas (10%), medullary thyroid carcinomas (5-10%), anaplastic carcinomas (1-2%), primary thyroid lymphomas (rare), and primary thyroid sarcomas (rare).
Hürthle cell carcinoma is a rare thyroid malignancy that is often considered a variant of follicular carcinoma.
– Papillary and Follicular carcinoma are slow-growing tumours
– Sporadic cases of Medullary thyroid carcinoma also typically manifest with painless solitary thyroid nodules in the early stages.
– Anaplastic thyroid carcinoma has the most aggressive biologic behaviour of all thyroid malignancies and has one of the worst survival rates of all malignancies in general. It manifests as a rapidly growing thyroid mass in contrast to a well-differentiated carcinoma, which are comparatively slow-growing. Patients commonly present with associated symptoms due to local invasion. Hoarseness and dyspnoea resulting from the involvement of the recurrent laryngeal nerve and airway occur in as many as 50% of patients.
– Almost all patients with primary thyroid lymphoma have either a clinical history or histological evidence of chronic lymphocytic thyroiditis. The risk of primary thyroid lymphoma increases 70-fold in patients with chronic lymphocytic thyroiditis compared with the general population. Regional and distant lymphadenopathy is common.

During pregnancy, profound changes in thyroid physiology occur to provide sufficient thyroid hormone (TH) to both the mother and foetus. This is particularly important during early pregnancy because the fetal thyroid starts to produce considerable amounts of TH only from approximately 20 weeks of gestation, until which time the foetus heavily depends on the maternal supply of TH. This supply of TH to the foetus, as well as increased concentrations of TH binding proteins (thyroxine-binding globulin) and degradation of TH by placental type 3 iodothyronine deiodinase, necessitate an increased production of maternal TH. This requires an intact thyroid gland and adequate availability of dietary iodine and is in part mediated by the pregnancy hormone human chorionic gonadotropin, which is a weak agonist of the thyroid-stimulating hormone (TSH) receptor. As a consequence, serum-free thyroxine (FT4) concentrations increase and TSH concentrations decrease from approximately the eighth week throughout the first half of pregnancy, resulting in different reference intervals for TSH and FT4 compared to the non-pregnant state.

The patient has hyperthyroidism and its most common cause is Grave’s Disease.
Grave’s Disease is an autoimmune disease due to circulating autoantibodies known as TSH receptor stimulating autoantibodies or Thyroid-stimulating immunoglobulins (TSIs) that bind to and activate thyrotropin receptors, causing the thyroid gland to grow and the thyroid follicles to increase the synthesis of thyroid hormone.

The patient’s history points to absence seizures. Carbamazepine has been shown to aggravate generalized seizure types, especially absence seizures, because it acts directly on the ventrobasal complex of the thalamus which is critical to the neurophysiology of absence seizures.

Selective sodium-glucose transporter-2 (SGLT2) is expressed in the proximal renal tubules and is responsible for the majority of the reabsorption of filtered glucose from the tubular lumen.
Empagliflozin; SGLT2 inhibitors reduce glucose reabsorption and lower the renal threshold for glucose, thereby increasing urinary glucose excretion, thus increasing the risk of urinary tract infections.

Primary hyperaldosteronism, also known as Conn’s Syndrome, is one of the most common causes of secondary hypertension (HTN).
The common clinical scenarios in which the possibility of primary hyperaldosteronism should be considered include the following:
– Patients with spontaneous or unprovoked hypokalaemia, especially if the patient is also hypertensive
– Patients who develop severe and/or persistent hypokalaemia in the setting of low to moderate doses of potassium-wasting diuretics
– Patients with treatment-refractory/-resistant hypertension (HTN)
Patients with severe hypokalaemia report fatigue, muscle weakness, cramping, headaches, and palpitations. They can also have polydipsia and polyuria from hypokalaemia-induced nephrogenic diabetes insipidus. Long-standing HTN may lead to cardiac, retinal, renal, and neurologic problems, with all the associated symptoms and signs.

In central and nephrogenic diabetes insipidus (DI), urinary osmolality will be less than 300 mOsm/kg after water deprivation. After the administration of ADH, the osmolality will rise to more than 750 mOsm/kg in central DI but will not rise at all in nephrogenic DI. In primary polydipsia, urinary osmolality be above 750 mOsm/kg after water deprivation. A urinary osmolality that is 300-750 mOsm/kg after water deprivation and remains below 750 mOsm/kg after administration of ADH may be seen in partial central DI, partial nephrogenic DI, and primary polydipsia.

Neuropathic pain may be defined as pain which arises following damage or disruption of the nervous system. It is often difficult to treat and responds poorly to standard analgesia.
The most recent update to the NICE guidelines for management of neuropathic pain occurred in 2013: first-line treatment* includes amitriptyline. If the first-line drug treatment does not work then move on to one of the other 3 drugs: duloxetine, gabapentin or pregabalin. Tramadol may be used as ‘rescue therapy’ for exacerbations of neuropathic pain. Topical capsaicin may be used for localised neuropathic pain (e.g. post-herpetic neuralgia). Pain management clinics may be useful in patients with resistant problems.

*please note that for some specific conditions the guidance may vary. For example carbamazepine is used first-line for trigeminal neuralgia.

Achondroplasia is the most common type of short-limb disproportionate dwarfism. A single gene mapped to the short arm of chromosome 4 (band 4p16.3) is responsible for achondroplasia and is transmitted as an autosomal dominant trait. All people with achondroplasia have a short stature.
Characteristic features of achondroplasia include an average-size trunk, short arms and legs with particularly short upper arms and thighs, limited range of motion at the elbows, and an enlarged head (macrocephaly) with a prominent forehead. Fingers are typically short and the ring finger and middle finger may diverge, giving the hand a three-pronged (trident) appearance. People with achondroplasia are generally of normal intelligence.
Examination of the infant after birth shows increased front-to-back head size. There may be signs of hydrocephalus. It may be diagnosed radiographically at birth, or becomes obvious within the first year with disparity between a large skull, normal trunk length and short limbs.

Euthyroid sick syndrome (also known as nonthyroidal illness syndrome) can be described as abnormal findings on thyroid function tests that occurs in the setting of a nonthyroidal illness (NTI), without pre-existing hypothalamic-pituitary and thyroid gland dysfunction. After recovery from an NTI, these thyroid function test result abnormalities should be completely reversible.
Multiple alterations in serum thyroid function test findings have been recognized in patients with a wide variety of NTIs without evidence of pre-existing thyroid or hypothalamic-pituitary disease. The most prominent alterations are low serum triiodothyronine (T3) and elevated reverse T3 (rT3), leading to the general term low T3 syndrome. Thyroid-stimulating hormone (TSH), thyroxine (T4), free T4 (FT4), and free T4 index (FTI) also are affected in variable degrees based on the severity and duration of the NTI. As the severity of the NTI increases, both serum T3 and T4 levels drop, but they gradually normalize as the patient recovers.
Reverse T3 is used to differentiate between this condition and secondary thyroid failure.

This patient presentation is unlikely to be an L5 nerve root lesion given the results of the MRI scan. Therefore, the most likely diagnosis is a mononeuritis affecting the left common peroneal nerve. This would lead to sensory loss over the dorsum of the foot and anterolateral leg on the left.

The patient most likely has Klinefelter’s syndrome.
Klinefelter syndrome (KS) refers to a group of chromosomal disorders in which the normal male karyotype, 46,XY, has at least one extra X chromosome. XXY aneuploidy, the most common human sex chromosome disorder. It is also the most common chromosomal disorder associated with male hypogonadism and infertility.
Klinefelter syndrome is characterized by hypogonadism (micro-orchidism, oligospermia/azoospermia), gynecomastia in late puberty, hyalinization and fibrosis of the seminiferous tubules, elevated urinary gonadotropin levels, and behavioural concerns.

The diagnosis is Refsum’s disease. This is an autosomal recessive disorder that causes a sensorimotor peripheral neuropathy. It is caused by defective alpha oxidation of phytanic acid leading to its accumulation in tissues. Cardiac conduction abnormalities and cardiomyopathies may also occur.
Epiphyseal dysplasia causes a characteristic shortening of the fourth toe. Serum phytanic acid levels are elevated. Treatment is by dietary restriction of foods containing phytanic acid (dairy products, fish, beef and lamb).

Low body weight. Excessively low body weight — about 10 percent under normal weight — interrupts many hormonal functions in your body, potentially halting ovulation.
In Polycystic ovaries there is excess weight gain.

Several dipeptidyl peptidase-4 (DPP-4) inhibitors are in clinical development; these are orally active and increase levels of active glucagon-like peptide-1 (GLP-1), which in turn increases insulin secretion and reduces glucagon secretion, thereby lowering glucose levels.
Sitagliptin and vildagliptin both have a long duration of action, allowing once-daily administration. Both sitagliptin and vildagliptin are safe and tolerable with a low risk of hypoglycaemia. In drug-naïve subjects with type 2 diabetes, both sitagliptin and vildagliptin reduce A1C levels by ,1% as monotherapy.

Normal cerebrospinal fluid (CSF) glucose together with lymphocytosis, an increased opening pressure and raised CSF protein are typical of a viral meningitis.

Cerebral venous sinus thrombosis (CVST) is associated with headache (>90% of cases), seizures, focal weakness (40%) and papilledema (40%), all seen in this patient.
Risk factors for CVST include genetic or acquired prothrombotic disorders, pregnancy, the oral contraceptive pill, vasculitis, malignancy, dehydration and infection. However, there are multiple other associated factors.
Diagnosis is normally confirmed with magnetic resonance venography (MRV). Treatment is with anticoagulation, initially with heparin and subsequently with warfarin.

Sitagliptin-induced pancreatitis can occur at any time after the initiation of therapy, even after several years. Patients taking sitagliptin who present with signs and symptoms of mild or severe pancreatitis should immediately discontinue sitagliptin and use an alternate medication regimen for control of type 2 diabetes.
In response to pancreatitis reported in post-marketing surveillance through the Adverse Event Reporting System (AERS), the FDA has issued revised prescribing information for sitagliptin stating that cases of acute pancreatitis have been reported with use, to monitor closely for signs and symptoms of pancreatitis, and to use sitagliptin with caution in patients with a history of pancreatitis.

The patient’s history and presentation and familial history, meets the diagnostic criteria for Neurofibromatosis type I, presenting with neurofibromas noted in this patient as hyperpigmented macules and freckles, musculoskeletal disorders like the scoliosis in this case, and a familial history. Neurofibromatosis type I is caused by a mutation on Chromosome 17.

Three classes of medications are appropriate for the management of major triglyceride elevations: fibric acid derivatives, niacin, and omega-3 fatty acids.

Fibrate is used as a first-line agent for reduction of triglycerides in patients at risk for triglyceride-induced pancreatitis.

High-dose niacin (vitamin B-3) (1500 or more mg/d) decreases triglyceride levels by at least 40% and can raise HDL cholesterol levels by 40% or more. Niacin also reliably and significantly lowers LDL cholesterol levels, which the other major triglyceride-lowering medications do not.

Omega-3 fatty acids are attractive because of their low risk of major adverse effects or interaction with other medications. At high doses (>4 g/d), triglycerides are reduced.

Astereognosis is associated with lesions to the parietal lobe, not the temporal lobe, so this symptom would not arise in this patient.

The pons is above the level of decussation of the corticospinal tracts so a pontine lesion would cause a contralateral limb weakness.
The facial motor nucleus is located in the pons and supplies the ipsilateral facial muscles.
A right cerebral lesion would give left upper and lower limb weakness. It would also cause a left sided facial weakness.
A left cerebral lesion would give right upper and lower limb weakness with right facial weakness.
Finally, a cervical spinal cord lesion would not cause a facial weakness.

The patient has small cell lung cancer presented by paraneoplastic syndrome; Ectopic ACTH secretion.

Small cell lung cancer (SCLC), previously known as oat cell carcinoma is a neuroendocrine carcinoma that exhibits aggressive behaviour, rapid growth, early spread to distant sites, exquisite sensitivity to chemotherapy and radiation, and a frequent association with distinct paraneoplastic syndromes.
Common presenting signs and symptoms of the disease, which very often occur in advanced-stage disease, include the following:
– Shortness of breath
– Cough
– Bone pain
– Weight loss
– Fatigue
– Neurologic dysfunction
Most patients with this disease present with a short duration of symptoms, usually only 8-12 weeks before presentation. The clinical manifestations of SCLC can result from local tumour growth, intrathoracic spread, distant spread, and/or paraneoplastic syndromes.
SIADH is present in 15% of the patients and Ectopic secretion of ACTH is present in 2-5% of the patients leading to ectopic Cushing’s syndrome.

In the petrous temporal bone the facial nerve produces three branches:
1. The greater petrosal nerve, which transmits preganglionic parasympathetic fibres to the sphenopalatine ganglion. These postganglionic fibres supply the lacrimal gland and the glands in the nasal cavity;
2. The nerve to stapedius;
3. Parasympathetic fibres to the submandibular and sublingual glands and taste fibres from the anterior two-thirds of the tongue.

Elderly patients with severe hypothyroidism often present with variable symptoms that may be masked or potentiated by co-morbid conditions. Characteristic symptoms may include fatigue, weight gain, cold intolerance, hoarseness, constipation, and myalgias. Neurologic symptoms may include ataxia, depression, and mental status changes ranging from mild confusion to overt dementia.
Clinical findings that may raise suspicion of thyroid hormone deficiency include hypothermia, bradycardia, goitrous enlargement of the thyroid, cool dry skin, myxoedema, delayed relaxation of deep tendon reflexes, a pericardial or abdominal effusion, hyponatremia, and hypercholesterolemia.

The patient has a greatly reduced free T4 concentration, is hypothermic, unconscious and has evidence of associated heart failure. All of those support the diagnosis of profound hypothyroidism.

Spinal cord hemisection, also known as Brown-Sequard syndrome, is associated with symptoms affecting one spinothalamic and one corticospinal tract. Symptoms include ipsilateral paralysis, loss of vibration and position sense, and hyperreflexia below the level of the lesion. Contralateral loss of pain and temperature sensation is also seen, usually beginning 2-3 segments below the level of the lesion.

Prolactinomas, benign lesions that produce the hormone prolactin, are the most common hormone-secreting pituitary tumours.
Based on its size, a prolactinoma can be classified as a microprolactinoma (< 10 mm diameter) or a macroprolactinoma (>10 mm diameter). If the prolactinoma is large enough to compress the surrounding normal hormone-secreting pituitary cells, it may result in deficiencies of one or more hormones (e.g., thyroid-stimulating hormone [TSH], growth hormone [GH], adrenocorticotropic hormone). However, the patient has microadenoma so it is unlikely to cause compression manifestations.
Hyperprolactinemia inhibits GnRH secretion from the medial basal hypothalamus and LH release from the pituitary.

Downbeat nystagmus (DBN) suggests a lesion in the lower part of the medulla. Chiari Type I malformation usually presents with symptoms due to brain stem and lower cranial nerve dysfunction, which includes DBN.

This woman has a history that is suggestive of Guillain– Barré syndrome. This may be precipitated by Campylobacter, and her history of recent diarrhoeal illness is pointing towards that. Certain features point to a poor prognosis, including rapidity of onset, reduced vital capacity or respiratory failure, age >40 and reduced amplitude of compound muscle action potential. Her inability to perform spirometry and desaturating whilst lying flat are suggestive of impending respiratory muscle weakness. Review for consideration of ventilation is recommended. Further management of choice for Guillain-Barre syndrome is IV immunoglobulins. Steroids have no value in the treatment of the condition.

In patients with polycystic ovarian syndrome (PCOS), FSH levels are within the reference range or low. Luteinizing hormone (LH) levels are elevated for Tanner stage, sex, and age. The LH-to-FSH ratio is usually greater than 3.

Women with PCOS have abnormalities in the metabolism of androgens and oestrogen and in the control of androgen production. PCOS can result from abnormal function of the hypothalamic-pituitary-ovarian (HPO) axis.
The major features of PCOS include menstrual dysfunction, anovulation, and signs of hyperandrogenism. Other signs and symptoms of PCOS may include the following:
– Hirsutism
– Infertility
– Obesity and metabolic syndrome
– Diabetes
– Obstructive sleep apnoea

Androgen excess can be tested by measuring total and free testosterone levels or a free androgen index. An elevated free testosterone level is a sensitive indicator of androgen excess. Other androgens, such as dehydroepiandrosterone sulphate (DHEA-S), may be normal or slightly above the normal range in patients with polycystic ovarian syndrome (PCOS). Levels of sex hormone-binding globulin (SHBG) are usually low in patients with PCOS.

Some women with PCOS have insulin resistance and an abnormal lipid profile (cholesterol >200 mg/dL; LDL >160 mg/dL). Approximately one-third of women with PCOS who are overweight have impaired glucose tolerance or type 2 diabetes mellitus by 30 years of age.