title: A case of macroprolactinoma and elevated insulin-like growth factor-I in a young boy.
abstract: We report a case of a 10-y-old boy who presented with persistent headache and was found to have a giant prolactinoma. Laboratory evaluation revealed markedly elevated prolactin (PRL) level, thyroid-stimulating hormone (TSH) deficiency, and elevated insulin-like growth factor-I (IGF-I). He had normal random growth hormone (GH) but non-suppressible GH during oral glucose tolerance test (OGTT). Cabergoline treatment was initiated and was well tolerated. Therapy successfully reduced PRL levels, normalized IGF-I levels, and reduced tumor size.
  
  
  CONCLUSIONS
  Our patient presented with a GH-PRL-secreting tumor. Dopamine agonists are recommended as the treatment of choice for prolactinomas. However, there should be careful attention to GH status when treating GH-PRL-secreting tumor with dopamine agonists alone. IGF-I levels should be followed in all patients with prolactinoma, even in those with normal basal GH concentrations, because of the possibility of GH co-secretion.
authors.affiliation: Divisions of Pediatric Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Ohio 45229, USA. ori.eyal@chmcc.org
authors.forename: Ori
authors.initials: O
authors.lastname: Eyal
authors.forename: Lena N
authors.initials: LN
authors.lastname: Naffaa
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Elder
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D000077465:Cabergoline; D002648:Child; D004873:Ergolines / Q000008:administration & dosage / Q000627:therapeutic use; D005951:Glucose Tolerance Test; D006801:Humans; D007037:Hypothyroidism / Q000150:complications; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D010911:Pituitary Neoplasms / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D015175:Prolactinoma / Q000097:blood* / Q000150:complications / Q000188:drug therapy
chemical_list: D000970:Antineoplastic Agents; D004873:Ergolines; D007334:Insulin-Like Growth Factor I; D000077465:Cabergoline