Gigаntism (Study Outline) Fоr study оnly—this is nоt medicаl аdvice or a substitute for professional care. 1. Background Definition:Gigantism is excessive growth hormone (GH) secretion before epiphyseal plate closure in children/adolescents, leading to abnormally accelerated linear growth and tall stature.After epiphyseal fusion, the same process manifests as acromegaly. Pathophysiology: GH excess → ↑ hepatic IGF-1, promoting growth of bone, cartilage, and soft tissues. Because epiphyseal plates remain open, longitudinal bone growth increases dramatically. Excess GH/IGF-1 also causes organomegaly, metabolic dysfunction, and pituitary mass effects. Etiology: Pituitary somatotroph adenoma (most common). Rare: ectopic GHRH-producing tumors (pancreatic, bronchial). Genetic syndromes: McCune–Albright, Carney complex, MEN 1. Epidemiology: Very rare; typically presents in adolescence. 2. History Key Presentation: Rapid growth velocity above expected percentiles. Extreme height compared with peers or family norms. Associated Symptoms: Headaches, visual changes (bitemporal hemianopsia) from pituitary mass. Excessive sweating, fatigue, heat intolerance. Joint pain, rapid shoe and clothing size changes. Metabolic: weight gain, insulin resistance, possible diabetes. Reproductive: delayed puberty, menstrual irregularities. Organ/System Effects: Enlargement of hands, feet, facial features (may resemble acromegaly features). Cardiomegaly, sleep apnea. Historical Clues: Growth acceleration charted on pediatric growth curves. Symptoms of pituitary mass (headache, visual deficits). 3. Exam Findings Growth/Anthropometrics: Tall stature with accelerated growth velocity. Arm span often exceeds height. Craniofacial Features: Frontal bossing, prognathism (jaw protrusion), nasal enlargement. Spaced teeth, macroglossia. Musculoskeletal: Large hands/feet, joint laxity or pain. Neurologic: Visual field defects (classically bitemporal hemianopsia). Skin: Oily skin, acne, skin tags. Cardiovascular: Hypertension, signs of cardiomyopathy in advanced cases. 4. Making the Diagnosis Step 1 – Screening: Serum IGF-1: elevated; most reliable initial test (stable marker of GH activity). Step 2 – Confirmatory Testing: Oral glucose tolerance test (OGTT) with GH measurement: Normal response: glucose suppresses GH. Gigantism: GH fails to suppress after glucose load. Step 3 – Identify Source: MRI of the pituitary gland: Detects pituitary adenoma (micro or macroadenoma). If MRI negative → evaluate for ectopic GHRH via serum GHRH level; CT/MRI of chest/abdomen. Additional Labs: Fasting glucose/insulin (insulin resistance). Other pituitary hormones (possible compression effects). Gold Standard: Elevated IGF-1 + failure of GH suppression on OGTT + pituitary adenoma on MRI. 5. Management (Exam Concepts) (Conceptual overview only—no dosing or treatment regimens.) 1. First-Line Therapy Transsphenoidal resection of pituitary adenoma. 2. Medical Therapy Somatostatin analogs (octreotide, lanreotide) — suppress GH secretion. GH receptor antagonist (pegvisomant) — blocks IGF-1 production. Dopamine agonists (cabergoline) — used in some GH/prolactin co-secreting tumors. 3. Radiation Therapy For residual tumor or persistent disease not controlled with surgery/medications. 4. Long-Term Monitoring Serial IGF-1 measurements. Periodic pituitary imaging. Screen for cardiomyopathy, sleep apnea, and metabolic complications. QUESTION NBME-Style Practice Question A 14-year-old boy is brought to clinic for rapid growth over the past year. His height increased from the 75th to >99th percentile. He reports headaches and needing larger shoes every few months. Exam shows frontal bossing, enlarged hands, and visual field deficits. Labs reveal markedly elevated IGF-1. After an oral glucose load, GH levels remain high. Which of the following is the most appropriate next step to determine the underlying cause? A. Serum GHRH levelB. MRI of the pituitary glandC. Bone age radiographD. Abdominal CT scan
Pаssаge Eight (Questiоns 61 - 63) Un jоven cаmpesinо hacía su primer viaje de su pueblo a la ciudad conduciendo una carreta cargada de artículos para el mercado. Resultó que en su trayecto tenía que atravesar por un túnel muy largo, el cual se veía como un tubo oscuro con una pequeña luz al final. El muchacho miró aquello asombrado y dijo: -Si entro con mi carga por allí, no podré salir pues la salida es demasiado estrecha. Disgustado, volvió con la carga a su pueblo. Es innecesario decir que tan sólo se trataba de una ilusión óptica. Si hubiera atravesado el túnel habría encontrado que tan ancha era la entrada como la salida. El campesino no entró en el túnel porque ______.
Pаssаge Six (Questiоns 54 - 57) Pоr аquellоs días no era costumbre que los jóvenes estudiantes fueran a la biblioteca. Juanito se reunía con otros estudiantes como él en el Bar del Toro y allí se divertían y se contaban las últimas noticias. Todos los dineros que su papá le daba, Juanito los gastaba en el bar. Apenas terminados los estudios, hubo un cambio en el joven; perdió el interés en su carrera; empezó a creer ridículos aquellos estudios. No tardó en convencerse que era mejor no leer nada. Tenía Juanito entonces veintitrés años. Lo conocí en un almuerzo que Federico dio a sus amigos. Ahora le gustaban los estudios
Select оne оf the twо possible choices to complete the sentence. If the sentence is correct аs is, select "No Chаnge" Exаmple: Pablo es___muchacho a. un b. una "a" is the right answer. ¿ ______ le gusta la paella?