title: [High uptake on 11C methionine PET scan in the pituitary gland of a patient with cerebral glioma after surgical abortion].
abstract: Positron emission tomography (PET) with various tracers provides physiologic and biochemical information of living organs. Since radiologic examinations are usually avoided in pregnant women, mainly because of the radiation risk to the fetus, little is known about the effect of pregnancy on cerebral blood flow and metabolism. This paper reports findings of a 11C methionine PET scan of the pituitary gland in a woman after an abortion. The patient was a 31-year-old woman who suffered a seizure in the 9th week of her second pregnancy. On admission, computed tomography showed an abnormal mass lesion in the right frontal lobe, and a brain tumor was suspected. The patient and her family asked that that pregnancy be terminated. Seven days after a surgical abortion, methionine PET was performed. The scan showed high methionine uptake in the pituitary gland as well as in the right frontal lobe tumor. We suspected that another tumor was present in the pituitary gland. The right frontal tumor was partially resected, and pathologic examination of the resected specimen showed an astrocytoma (grade 2). After the operation, the patient received 50 Gy irradiation and chemotherapy. Two months after the operation, we performed a second methionine PET scan, which showed high uptake in the residual right frontal tumor but not in the pituitary gland. Results of other radiologic studies of the pituitary gland were normal. These findings suggest that the transport of 11C methionine into the pituitary gland may increase during pregnancy. Moreover, the pituitary gland of pregnancy should be a part of the differential diagnosis of pituitary adenomas in PET scanning. The change in physiologic uptake by the female pituitary gland should be taken into account in the diagnosis of pituitary adenoma with methionine PET.
authors.affiliation: Department of Neurosurgery, Showa University School of Medicine, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hanakawa
authors.forename: H
authors.initials: H
authors.lastname: Ikeda
authors.forename: K
authors.initials: K
authors.lastname: Ishii
authors.forename: S
authors.initials: S
authors.lastname: Asamoto
authors.forename: T
authors.initials: T
authors.lastname: Iwata
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D000032:Abortion, Therapeutic; D000328:Adult; D001254:Astrocytoma / Q000000981:diagnostic imaging*; D001932:Brain Neoplasms / Q000000981:diagnostic imaging*; D002250:Carbon Radioisotopes / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D008715:Methionine / Q000493:pharmacokinetics; D010902:Pituitary Gland / Q000378:metabolism*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D014055:Tomography, Emission-Computed
chemical_list: D002250:Carbon Radioisotopes; D008715:Methionine