PRL and hyperprolactinemia: Likewise, in several cases, the presence of macroprolactin has been confused with other causes of hyperprolactinemia (15), while in another case report, Gulbahar O. described a 33-year-old woman with no specific symptoms having falsely elevated PTH, TSH, ACTH, FSH, IGF-1, prolactin, β-human chorionic gonadotropin, and calcitonin levels that return to normality after to PEG precipitation (9).