title: Prolactin-producing pituitary adenoma with atypical spindle cell morphology: a case report.
abstract: Reported herein is a 25-year-old woman who was treated for a large and highly atypical prolactin-producing pituitary adenoma. On presentation, she exhibited right hemiparesis and left-sided visual loss, associated with amenorrhea. A massive (>5 cm) intra- and suprasellar lesion was seen on imaging, and her serum prolactin level was 4408 ng/ml. The patient received dopamine agonist treatment preoperatively for 4 weeks. To resect the tumor, a two-stage excision was required. Histologically, the specimen was composed of polygonal or spindle cells showing marked nuclear pleomorphism and/or multinucleation. Fibrosis was also focally conspicuous. Differential diagnoses included pituitary adenoma, pituitary carcinoma, pituicytoma, paraganglioma, spindle cell oncocytoma, and meningioma. Immunohistochemically, the tumor cells were positive for prolactin, chromogranin-A, and synaptophysin, but were negative for glial fibrillary acidic protein, S-100 protein, epithelial membrane antigen, and vimentin. No apparent cerebrospinal or systemic metastases are found. Ultimately, prolactin-producing pituitary adenoma was diagnosed. Our case highlights the difficulty in definitively diagnosing an unusual prolactin-producing adenoma based on histopathology alone and the importance of referring to clinical information and immunohistochemical findings when deriving the diagnosis.
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, 1-1-1 Zokumyoin, Chikushino, Fukuoka, 818-8502, Japan. ritsurou@hotmail.com.
authors.forename: Ritsurou
authors.initials: R
authors.lastname: Inoue
authors.affiliation: Department of Pathology, School of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan. mikikoss@fukuoka-u.ac.jp.
authors.forename: Mikiko
authors.initials: M
authors.lastname: Aoki
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, 1-1-1 Zokumyoin, Chikushino, Fukuoka, 818-8502, Japan. fwip4873@mb.infoweb.ne.jp.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Matsumoto
authors.affiliation: Department of Pathology, Fukuoka University Chikushi Hospital, 1-1-1 Zokumyoin, Chikushino, Fukuoka, 818-8502, Japan. haraoka@fukuoka-u.ac.jp.
authors.forename: Seiji
authors.initials: S
authors.lastname: Haraoka
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, 1-1-1 Zokumyoin, Chikushino, Fukuoka, 818-8502, Japan. kazekawa3426@gmail.com.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kazekawa
authors.affiliation: Department of Pathology, School of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan. kaznabes@fukuoka-u.ac.jp.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Nabeshima
mesh_terms: D000236:Adenoma / Q000097:blood / Q000150:complications* / Q000473:pathology; D000328:Adult; D005260:Female; D006801:Humans; D018331:Nevus, Spindle Cell / Q000097:blood* / Q000473:pathology*; D010911:Pituitary Neoplasms / Q000097:blood / Q000150:complications* / Q000473:pathology; D011379:Prognosis; D015175:Prolactinoma / Q000209:etiology* / Q000473:pathology