Pituitary Disorders Suranut Charoensri, MD Division of Endocrinology and Metabolism Department of Medicine Faculty of Medicine, Khon Kaen University
Anatomical Landmarks Nat Rev Endocrinol 2014;10:423-435
Physiology PRL GH Gn (FSH,LH) TSH ACTH ADH Oxytocin Mescher AL: Junqueira s Basic Histology: Test and Atlas, 12 th Edition: http://accessmedicine.com
Physiology CRH TRH Dopamine GnRH GHRH X X MSH ACTH TSH Prolactin FSH,LH GH (hyperpigment) Cortisol Androgen T4/T3 Lactation Testosterone Estradiol IGF-1 Growth When pituitary stalk is disrupted, all anterior pituitary hormones will be decreased except PRL which will be increased (stalk effect) Adapted from Williams Textbook of Endocrinology, 13th edition 2016
Presentations 1. Hormonal excess (hyper) 2. Hormonal deficiency (hypo) 3. Mass effect Neuro-ophthalmic Increased intracranial pressure 4. Asymptomatic or unrelated symptoms Pituitary incidentaloma
History Taking Hyper Hypo Mass PRL Galactorrhea GH Facial/body dysmorphic change Gn Testis enlarge (rare) ACTH Cushing s TSH Hyperthyroid PRL Lactation GH Growth Gn W : Amenorrhea, fertility status M : Morning erection, shaving ACTH Cortisol : AI Androgen : body hair in women TSH : Hypothyroid ADH : Polyuria (DI) CN involvement II Blurred vision III, IV, VI Diplopia, abnormal gaze V1, V2 Facial numbness Visual field Narrowed VF Increased ICP Unexplained headache Nausea/vomiting
Physical Examination Hyper Hypo Mass PRL - GH Acromegalic change, OSA Gn Enlarged testis (rare) ACTH Cushing s TSH Hyperthyroid, thyroid gland enlarged PRL - GH Short stature Gn W : Breast (Tanner) M : Testis, scrotum, pubic hair, body hair ACTH Orthostasis body hair in women TSH Hypothyroid ADH - VA, VF, RAPD Optic disc ( ICP) Pupil, EOM Facial sensation Stiff neck Complete neuro exam Prader orchidometer
Investigations Hormonal profile Morning cortisol, FT4, TSH PRL, IGF-1, FSH, LH, ACTH, testosterone, estradiol Dynamic test (needed in some cases) GH suppression, ACTH stimulation, Insulin tolerance Imaging study MRI pituitary (CT brain, plain X-ray lateral skull film) Basic investigations Electrolyte, glucose, UA esp. Sp.gr., renal function, CBC
Lab Interpretation Cortisol Central adrenal insufficiency Morning cortisol < 3 mcg/dl : indicative of AI Morning cortisol > 15 mcg/dl : likely exclude AI Gray zone : ACTH stimulation test 1 mcg or 250 mcg test : similar accuracy < 18 mcg/dl at 30 or 60 minutes indicates AI ACTH level : helpful in indicative of primary AI (> 2-fold of UNL) Cortisol Cushing s disease Unsuppressible dexamethasone suppression test : cortisol > 1.8 mcg/dl Elevated 24-hour urine free cortisol ACTH level > 10 pg/ml : ACTH-dependent J Clin Endocrinol Metab 2016, 101(11):3888 3921 J Clin Endocrinol Metab 2016, 101(2):364 389 J Clin Endocrinol Metab 2008, 93(5):1526 1540
Lab Interpretation Thyroid Central hypothyroidism Low FT4 May have low, normal, or mildly elevated TSH (usually < 10 miu/l) Thyroid TSH-producing tumor (TSHoma) High FT4 Normal or elevated TSH (Inappropriate TSH secretion) Gonad Hypogonadotropic hypogonadism Low testosterone / estradiol Low or inappropriately normal FSH, LH Estradiol measurement may not necessary in post-menopausal women J Clin Endocrinol Metab 2016, 101(11):3888 3921
Normal MRI Pituitary First; locate pituitary Between these black holes Internal carotid artery Optic chiasm Cavernous sinus Pituitary Coronal T1 https://radiopaedia.org
Normal MRI Pituitary Coronal T1 Coronal T1 with Gd Coronal T2
Normal MRI Pituitary Optic nerve Stalk Posterior bright spot Sagittal T1
Normal MRI Pituitary Sagittal T1 Sagittal T2
Pituitary Microadenoma Coronal T1 Coronal T1 with Gd
Pituitary Macroadenoma (> 1 cm) Coronal T1 Coronal T1 with Gd
Coronal T1 with Gd Snow man sign
Coronal T1 Coronal T2
Hyperprolactinemia hysiological athological Pregnancy, lactation, exercise, coitus, stress, sleeping Macroprolactinemia harmacological *** Anti-emetics (antidopaminergic): Metoclopramide, Domperidone H2 blockers: Cimetidine Ranitidine Neuroleptics: Phenothiazine, Haloperidol, Risperidone Anticonvulsants: Phenytoin Antidepressants: TCA, SSRI Narcotics: Heroin, Morphine, Methadone Antihypertensives: Labetalol, Methyldopa, Verapamil, Reserpine Estrogen: Oral contraceptive pills In this case : Ask Hx of drugs Prolactinoma Stalk effect Seizure, Irradiation Chronic renal failure, Cirrhosis Breast stimulation Chest wall pathology Polycystic ovarian disease Primary hypothyroidism (TRH stimulate PRL) > 250 μg/dl : Prolactinoma is likely > 500 μg/dl : Diagnostic of macroprolactinoma Stop drugs at least 3 days then remeasurement Evaluate pregnancy (UPT), liver function, renal function, thyroid function Diagnosis and Treatment of Hyperprolactinemia: An Endocrine Society Clinical Practice Guideline 2011
Treatment of Prolactinoma Indications for treatment Macroprolactinoma Microprolactinoma All Med : Dopamine agonist Surgery : Non-responsive to DA or worsening of neuroophthalmic symptoms Symptomatic Galactorrhea Amenorrhea Infertility Med : Dopamine agonist Surgery : no indication Diagnosis and Treatment of Hyperprolactinemia: An Endocrine Society Clinical Practice Guideline 2011
Treatment of Prolactinoma Start dose: bromocriptine 1.25 2.5 mg OD titration Monitor prolactin level at 1 month after treatment Repeat MRI pituitary in 1 year Consider MRI pituitary within 3 months in Macroprolactinoma New symptoms e.g. visual disturbance, headache Prolactin level rising while on treatment VF examination in macroprolactinoma at risk of optic pathway compression Discontinue dopamine agonist (DA) when DA for at least 2 years // normalize prolactin // no visible tumor remnant Diagnosis and Treatment of Hyperprolactinemia: An Endocrine Society Clinical Practice Guideline 2011
Acromegaly Cutis verticis gyrata, frontal bossing, prominent supra-orbital ridge, coarse face, big nose, thick lips, prognathism, teeth separation and malocclusion, macroglossia, tongue indentation Acanthosis nigricans, skin tags, thyroid enlargement, OSA Galactorrhea, cardiomegaly, hepatosplenomegaly, colonic polyp Mass effects VA, VF, cranial nerve, hypopituitarism Oily skin, spade hands, carpal tunnel syndrome OA knee Spade feet
Diagnosis of Acromegaly IGF-1 (age-specific reference range) Normal Elevated Rule out OGTT * * Confirmation test Suppressed GH Non-suppressed GH Extra-pituitary acromegaly Normal Pituitary MRI Pituitary adenoma Chest and abdominal CT GH-secreting pituitary adenoma Adapted from Williams Textbook of Endocrinology, 13th edition 2016
Management of Acromegaly Comorbidities assessment CVD, DM, HT, OA, OSA Colonoscopy Thyroid U/S (if nodule present) Treatment First line: Surgery Second line: Medication Octreotide Dopamine agonist GH receptor antagonist (Pegvisomant) Acromegaly : An Endocrine Society Clinical Practice Guideline 2014