Hypothyroidism

Abstract

A 28-year-old-lady presented with headache for the last 1 year. It was holocranial, continuous, mild in intensity, and not associated with vomiting, seizures, focal neurological deficits, or visual defects. There was history of weight gain, fatigue, and generalized bodyache for the last 2 years. She also had secondary amenorrhea of 1 year duration. She received treatment for migraine without any relief. Subsequently, neuroimaging revealed a sellar mass with suprasellar extension (26 × 18 × 15 mm) with a hypointense area. Her visual acuity and visual field examination did not reveal any abnormality. She was referred for surgical intervention. The preoperative workup included hormonal evaluation which revealed serum T₃ 0.4 ng/ml (0.8–1.8), T₄ 1.4 μg/dl (4.8–12.6), and TSH 328 μIU/ml (0.45–4.2), prolactin 112 ng/ml (5–25), 0800h cortisol 280 nmol/l (171–536), serum osmolality 270 mosm/kg, and urine osmolality 350 mosm/kg. She was diagnosed to have nonfunctioning pituitary tumor with hypothyroidism and was referred to endocrinology for opinion. On further evaluation, she had dry and coarse skin, periorbital puffiness, hoarse voice, delayed deep-tendon reflexes, and galactorrhea. She had no goiter. Additional investigations revealed antithyroid peroxidase antibody 600 IU/ml (<34), LH 11 mIU/ml (2.4–12.6), FSH 13 mIU/ml (3.5–13.5), and estradiol 30 pg/ml (12.5–166), and ultrasound pelvis showed bilateral polycystic ovaries. She was diagnosed to have autoimmune thyroid disease (Hashimoto’s thyroiditis) with primary hypothyroidism, thyro-lactotrope hyperplasia, hyperprolactinemia, and secondary polycystic ovarian disease. She was started with levothyroxine 25 μg per day and the dose was escalated weekly to 150 μg per day. She was supplemented with hydrocortisone 20 mg per day in divided doses. After 6 weeks of therapy, she had resolution of symptoms, but did not resume menstruation. Her serum T₄ was 6.4 μg/dl, TSH 36 μIU/ml, prolactin 35 ng/ml, and 0800h cortisol after omission of hydrocortisone for 24 h 384 nmol/L; hence, hydrocoritosone was tapered and same dose of levothyroxine was continued. At 3 months of follow-up, she resumed her cycles and galactorrhea resolved. Repeat MRI showed regression of sellar–suprasellar mass (14 × 12 × 11 mm) with normalization of TSH and prolactin.