Falsely low serum prolactin in two cases of invasive macroprolactinoma.

摘要: The differential diagnosis of tumors at the base skull comprises meningiomas, neurinomas, gliomas, metastatic carcinomas, chordomas, epidermoids, and pituitary adenomas. About half adenomas are prolactinomas which unique in a sense that medical therapy causes rapid tumor shrinkage symptomatic improvement. We report on two patients an invasive macroprolactinoma was masked by apparently low prolactin levels caused high-dose hook effect chemiluminometric assay. first case 49 year old male with impairment hearing left side presented Department Otorhinolaryngology. A massive invasively growing demonstrated cranial MRI. Endocrine tests revealed normal function normoprolactinemia. patient underwent debulking surgery, occipitocervical fusion because destruction cervical vertebra subsequent irradiation. histopathological prolactinoma. repeat (PRL) sample, assayed using serial dilutions, real PRL level 89,700 ng/ml. Dopamine agonist initiated under declined parallel size. second 40 acute visual loss. Cranial MRI showed large skull. Based transnasal biopsy, preliminary poorly differentiated carcinoma for emergency irradiation performed. partial hypopituitarism moderate hyperprolactinemia. Hydrocortisone substituted dopamine started final sample dilution apparent rise maximum value 6,460 Under therapy, to values, size decreased nerve palsies disappeared. falsely initial work-up both were Serial dilutions serum samples is, therefore, mandatory diagnostic This avoids unnecessary aggressive dangerous treatment like surgery or radiotherapy cases where pharmacological may be choice.