Misdiagnosis due to the hook effect in prolactin assay.
Medical principles and practice : international journal of the Kuwait University, Health Science Centre, vol.17, no.5, pp.429-31, 2008 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 17 Issue: 5
- Publication Date: 2008
- Doi Number: 10.1159/000141512
- Journal Name: Medical principles and practice : international journal of the Kuwait University, Health Science Centre
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.429-31
- Keywords: prolactin, hook effect, misdiagnosis
- Open Archive Collection: AVESIS Open Access Collection
- Dokuz Eylül University Affiliated: Yes
Abstract
Objectives: To describe a patient who was misdiagnosed as having a nonfunctional pituitary tumor due to the hook effect on prolactin measurements. Clinical Presentation and Intervention: A 45-year-old female was admitted with visual disturbances, panhypopituitarism and central diabetes insipidus due to pituitary tumor recurrence. She had been operated 4 times earlier and received cranial irradiation for a suspected nonfunctional pituitary adenoma. Serum prolactin was moderately elevated (164.5 ng/ml), but increased markedly after 1: 100 dilution to 14,640 ng/ml. Diagnosis of a giant macroprolactinoma was made and cabergoline was started. Prolactin level normalized and a mild shrinkage of the tumor was achieved after 12 months of therapy. Conclusion: The hook effect must be kept in mind while evaluating a giant pituitary adenoma with moderately elevated prolactin levels. This way unnecessary surgical procedures or irradiation may be avoided. Copyright (c) 2008 S. Karger AG, Basel.