Sildenafil administration to patients who are using organic nitrates, either regularly and/or intermittently, in any form is contraindicated.
Organic nitrates and nitric oxide (NO) donors exert their therapeutic effects on blood pressure and vascular smooth muscle by the same mechanism as endogenous NO via increasing cGMP concentrations.

Mild deficiencies of 21-hydroxylase or 3-beta-hydroxysteroid dehydrogenase activity may present in adolescence or adulthood with oligomenorrhea, hirsutism, and/or infertility. This is termed nonclassical adrenal hyperplasia.
Late-onset or nonclassical congenital adrenal hyperplasia (NCAH) due to 21-hydroxylase deficiency is one of the most common autosomal recessive disorders. Reported prevalence ranges from 1 in 30 to 1 in 1000. Affected individuals typically present due to signs and symptoms of androgen excess.
Treatment needs to be directed toward the symptoms. Goals of treatment include normal linear growth velocity, a normal rate of skeletal maturation, ‘on-time’ puberty, regular menstrual cycles, prevention of or limited progression of hirsutism and acne, and fertility. Treatment needs to be individualized and should not be initiated merely to decrease abnormally elevated hormone concentrations.
Normal Ultrasound rules out Turner’s syndrome.

Classically, pheochromocytoma manifests with the following 4 characteristics:
– Headaches
– Palpitations
– Sweating
– Severe hypertension

The Endocrine Society, the American Association for Clinical Chemistry, and the European Society of Endocrinology have released clinical practice guidelines for the diagnosis and management of pheochromocytoma.
Biochemical testing via measurement of plasma free metanephrines or urinary fractionated metanephrines should be performed in patients suspected of having pheochromocytoma.

Catecholamines produced by pheochromocytomas are metabolized within chromaffin cells. Norepinephrine is metabolized to normetanephrine and epinephrine is metabolized to metanephrine. Because this process occurs within the tumour, independently of catecholamine release, pheochromocytomas are best diagnosed by measurement of these metabolites rather than by measurement of the parent catecholamines.

Carcinoid tumours are of neuroendocrine origin and derived from primitive stem cells in the gut wall, especially the appendix. They can be seen in other organs, including the lungs, mediastinum, thymus, liver, bile ducts, pancreas, bronchus, ovaries, prostate, and kidneys. While carcinoid tumours tend to grow slowly, they have the potential to metastasise.
Signs and symptoms seen in larger tumours may include the following:
– Periodic abdominal pain: Most common presentation for a small intestinal carcinoid; often associated with malignant carcinoid syndrome.
– Cutaneous flushing: Early and frequent (94%) symptom; typically affects head and neck.
– Diarrhoea and malabsorption (84%): Watery, frothy, or bulky stools, gastrointestinal (GI) bleed or steatorrhea; may or may not be associated with abdominal pain, flushing, and cramps.
– Cardiac manifestations (60%): Valvular heart lesions, fibrosis of the endocardium; may lead to heart failure with tachycardia and hypertension.
– Wheezing or asthma-like syndrome (25%): Due to bronchial constriction; some tremors are relatively indolent and result in chronic symptoms such as cough and dyspnoea.
– Pellagra with scale-like skin lesions, diarrhoea and mental disturbances.
– Carcinoid crisis can be the most serious symptom of the carcinoid tumours and life-threatening. It can occur suddenly or after stress, including chemotherapy and anaesthesia.

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.

Rotterdam criteria for the diagnosis of polycystic ovary syndrome:
Two of the following three criteria are required:
1. Oligo/anovulation
2. Hyperandrogenism
– Clinical (hirsutism or less commonly male pattern alopecia) or
– Biochemical (raised FAI or free testosterone)
3. Polycystic ovaries on ultrasound
Other aetiologies must be excluded such as congenital adrenal hyperplasia, androgen-secreting tumours, Cushing syndrome, thyroid dysfunction and hyperprolactinaemia.
Cushing’s is excluded because there would have been marked obesity, hypertension and other related features.

For medical management of carcinoid syndrome, there are two somatostatin analogues available, Octreotide and Lanreotide. Somatostatin is an amino acid peptide which is an inhibitory hormone, which is synthesized by paracrine cells located ubiquitously throughout the gastrointestinal tract. Both somatostatin analogues provide symptom relief in 50% to 70% of patients and biochemical response in 40% to 60% patients. Many studies have shown that Octreotide and Lanreotide also inhibit the proliferation of tumour cells.

Graves’ disease is the most common cause of thyrotoxicosis in pregnancy.

– Poor control of thyrotoxicosis is associated with pregnancy loss, pregnancy-induced hypertension, prematurity, low birth weight, intrauterine growth restriction, stillbirth, thyroid storm, and maternal congestive heart failure.

– Antithyroid drugs are the treatment of choice of hyperthyroidism during pregnancy. The lowest dose of ATD needed to maintain TT4 1.5× the upper limit of the non-pregnant reference range or FT4 at the upper limit of the reference range should be used.
Two different antithyroid drug (ATD) regimens are in common use for Grave’s disease: i) Titration method and ii) Block-and-replace method.
In the titration method, the usual starting dose is 15–30 mg/day methimazole (or equivalent doses of other thionamides); further to periodic thyroid status assessment, daily dose is tapered down to the lowest effective dose (avoiding both hyper- and hypothyroidism).
The block-and-replace method uses persistently high ATD doses in association with L-thyroxine replacement to avoid hypothyroidism; treatment lasts 6 months. This method has advantages and disadvantages over the titration method. Higher doses of ATDs may have a greater immunosuppressive action useful for a permanent remission of hyperthyroidism, but this effect remains to be demonstrated.
Avoidance of hypothyroidism or ‘escape’ of hyperthyroidism seems easier than with the titration method; treatment is shorter, and the number of visits lower. On the other hand, the much higher number of tablets taken every day may create problems of poor compliance. The block-and-replace method should not be used during pregnancy.

– Breastfeeding has been shown to be safe in mothers taking ATDs in appropriate doses.

Thyroid storm, also referred to as thyrotoxic crisis, is an acute, life-threatening, hypermetabolic state induced by excessive release of thyroid hormones (THs) in individuals with thyrotoxicosis.
Patients with thyroid storm should be treated in an ICU setting for close monitoring of vital signs and for access to invasive monitoring and inotropic support, if necessary.
– Supportive measures
If needed, immediately provide supplemental oxygen, ventilatory support, and intravenous fluids. Dextrose solutions are the preferred intravenous fluids to cope with continuously high metabolic demand.
– Correct electrolyte abnormalities.
– Treat cardiac arrhythmia, if necessary.
– Aggressively control hyperthermia by applying ice packs and cooling blankets and by administering acetaminophen (15 mg/kg orally or rectally every 4 hours).
– Antiadrenergic drugs.
– Thionamides: Correct the hyperthyroid state. Administer antithyroid medications to block further synthesis of thyroid hormones (THs).
High-dose propylthiouracil (PTU) or methimazole may be used for treatment of thyroid storm.
– Administer glucocorticoids to decrease peripheral conversion of T4 to T3. This may also be useful in preventing relative adrenal insufficiency due to hyperthyroidism and improving vasomotor symptoms.
– Bile acid sequestrants prevent reabsorption of free THs in the gut (released from conjugated TH metabolites secreted into bile through the enterohepatic circulation).
– Treat the underlying condition.

Diabetes insipidus (DI) is defined as the passage of large volumes (>3 L/24 hr) of dilute urine (< 300 mOsm/kg). It has the following 2 major forms:
– Central (neurogenic, pituitary, or neurohypophyseal) DI, characterized by decreased secretion of antidiuretic hormone (ADH; also referred to as arginine vasopressin [AVP])
– Nephrogenic DI, characterized by decreased ability to concentrate urine because of resistance to ADH action in the kidney
This patient has the central type from metastases.
In patients with central DI, desmopressin is the drug of choice. It is a synthetic analogue of antidiuretic hormone (ADH). It is available in subcutaneous, IV, intranasal, and oral preparations. Generally, it can be administered 2-3 times per day. Patients may require hospitalization to establish fluid needs. Frequent electrolyte monitoring is recommended during the initial phase of treatment.