PATHOLOGY - Disorders of the Pituitary -2024-01.pdf

Introduction to Disorders of the Pituitary Axis and Thyroid Disease Created by: Dr. Mariana Flores M. Modified by: Dr. Yisel Mi Guzmán Leguel Adapted from slides by: Dr. Carla Romo Jaramillo Objectives 1. Understand the states of hyperpituitarism in which there is excess secretion of trophic hormone...

Introduction to Disorders of the Pituitary Axis and Thyroid Disease Created by: Dr. Mariana Flores M. Modified by: Dr. Yisel Mi Guzmán Leguel Adapted from slides by: Dr. Carla Romo Jaramillo Objectives 1. Understand the states of hyperpituitarism in which there is excess secretion of trophic hormones. 2. Identify states of hypopituitarism when trophic hormones are deficient. 3. Identify the pathogenesis and clinical manifestations of these disorders. 4. To distinguish clinical scenarios when there are local mass effects. 5. Review disorders specific to the Posterior pituitary (ADH) and associated changes in fluid and electrolyte balances. ADENOMAS Peak incidence is from 35 to 60 years of age. Most common genetic abnormality: Mutation of the GNAS gene. Morphologic features: cellular monomorphism & absence of a reticulin network. Classification: Macroadenomas (>1 cm diameter) Mass effects → Visual disturbances, increased ICP (headache, nausea & vomiting), hemorrhages. Microadenomas ( thirst and polydipsia > lifethreatening dehydration. Diabetes Insipidus Diabetes insipidus (DI) literally means a large volume of urine (diabetes) that is tasteless (insipid). Increased ADH – SIADH ADH excess → resorption of excessive amounts of free water → hyponatremia. Etiologies: Secretion of ectopic ADH by malignant neoplasms (particularly small-cell carcinomas of the lung), non-neoplastic diseases of the lung, and local injury to the hypothalamus or neurohypophysis. Clinical Manifestations: Hyponatremia, cerebral edema, and neurologic dysfunction. Total body water is increased (blood volumen remains normal, and peripheral edema does not develop). Bibliography Endocrine System, Vinay Kumar MBBS, MD, FRC Path, Abul K. Abbas MBBS and Jon C. Aster MD, PhD. Robbins Pathologic Basis of Disease, Chapter 24 Daly, A. F., & Beckers, A. (2020). The Epidemiology of Pituitary Adenomas. Endocrinology and Metabolism Clinics of North America. doi:10.1016/j.ecl.2020.04.002