title: Pituitary hyperplasia resulting from primary hypothyroidism mimicking macroadenomas.
abstract: Three patients presented with clinical and imaging features suggestive of a primary functional pituitary adenoma. Surprisingly, thyroid function testing revealed co-existing primary hypothyroidism. The pituitary tumours represented hyperplasia of anterior pituitary thyrotrophs secondary to hypothyroidism. Complete regression was achieved with thyroxine replacement therapy. Careful attention should be paid to differentiating this condition from prolactinoma or the rare TSH producing adenoma.
authors.affiliation: Department of Pediatrics, Tulane University School of Medicine, New Orleans, Louisiana, USA.
authors.forename: M
authors.initials: M
authors.lastname: Young
authors.forename: K
authors.initials: K
authors.lastname: Kattner
authors.forename: K
authors.initials: K
authors.lastname: Gupta
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000293:Adolescent; D000328:Adult; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000175:diagnosis; D007037:Hypothyroidism / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D010911:Pituitary Neoplasms / Q000175:diagnosis*; D013961:Thyroid Gland / Q000473:pathology*; D013974:Thyroxine / Q000627:therapeutic use; D014057:Tomography, X-Ray Computed
chemical_list: D013974:Thyroxine