Background: Pituitary carcinomas are rare neoplasms whose designation requires demonstration of metastatic disease. No specific morphologic features can reliably distinguish pituitary carcinomas from pituitary adenomas, rendering the diagnosis particularly challenging. Furthermore, as reports of pituitary carcinoma on fine needle aspiration (FNA) biopsy are exceedingly rare in the literature, the cytological features of pituitary carcinoma are poorly characterized. Case Report: Here we describe a case of pituitary carcinoma in a 67-year-old woman with history of recurrent adrenocorticotropic hormone (ACTH)-producing pituitary adenoma who presented with a persistent left cervical nodule for 2 years. Ultrasound-guided FNA of the nodule consisted of loosely cohesive clusters of epithelioid cells with marked cytologic atypia, intermediate to large nuclei, relatively irregular nuclear contour, coarse granular chromatin, prominent nucleoli, and delicate finely granular cytoplasm. Immunohistochemical stains performed on the cell block revealed positivity for synaptophysin, chromogranin and ACTH with an increased Ki-67 proliferation index (approximately 25%). Review of the patient's previously resected pituitary tumor showed similar cytomorphologic features. Conclusion: Given the similar cytologic features of pituitary carcinomas compared to other neuroendocrine tumors, it is important to obtain a complete clinical history and maintain a high index of suspicion in order to make a correct diagnosis of pituitary carcinoma on FNA.

1.
Scheithauer BW, Kovacs K, Horvath E, Silva AI, Lloyd RV: Pathology of the pituitary and sellar region; in Perry A, Brat DJ (eds): Practical Surgical Neuropathology: A Diagnostic Approach. Philadelphia, Churchill Livingstone, 2010.
2.
Scheithauer BW, Kovacs KT, Horvath E, et al: Pituitary carcinoma; in DeLellis RA, Lloyd RV, Heitz PU, Eng C (eds): World Health Organization Classification of Tumours: Pathology and Genetics - Tumours of Endocrine Organs. Lyon, IARC Press, 2004, pp 36-39.
3.
Pernicone PJ, Scheithauer BW, Sebo TJ, Kovacs KT, Horvath E, Young WF Jr, Lloyd RV, Davis DH, Guthrie BL, Schoene WC: Pituitary carcinoma: a clinicopathologic study of 15 cases. Cancer 1997;79:804-812.
4.
Heaney AP: Clinical review: pituitary carcinoma: difficult diagnosis and treatment. J Clin Endocrinol Metab 2011;96:3649-3660.
5.
Cartwright DM, Miller TR, Nasr AJ: Fine-needle aspiration biopsy of pituitary carcinoma with cervical lymph node metastases: a report of two cases and review of the literature. Diagn Cytopathol 1994;11:68-73.
6.
Ceyhan K, Yagmurlu B, Dogan BE, Erdogan N, Bulut S, Erekul S: Cytopathologic features of pituitary carcinoma with cervical vertebral bone metastasis: a case report. Acta Cytol 2006;50:225-230.
7.
Corbacho C, Jiménez-Heffernan JA, Tejerina E, Sanz E: Fine needle aspiration cytology of pituitary carcinoma metastatic to the liver. Acta Cytol 2010;54(5 suppl):1059-1061.
8.
Yakoushina TV, Lavi E, Hoda RS: Pituitary carcinoma diagnosed on fine needle aspiration: report of a case and review of pathogenesis. Cytojournal 2010;7:14.
9.
Selman WR, Laws ER Jr, Scheithauer BW, Carpenter SM: The occurrence of dural invasion in pituitary adenomas. J Neurosurg 1986;64:402-407.
10.
Thapar K, Kovacs K, Scheithauer BW, Stefaneanu L, Horvath E, Pernicone PJ, Murray D, Laws ER Jr: Proliferative activity and invasiveness among pituitary adenomas and carcinomas: an analysis using the MIB-1 antibody. Neurosurgery 1996;38:99-106; discussion 106-107.
11.
Thapar K, Yamada Y, Scheithauer B, Kovacs K, Yamada S, Stefaneanu L: Assessment of mitotic activity in pituitary adenomas and carcinomas. Endocr Pathol 1996;7:215-221.
12.
Thapar K, Scheithauer BW, Kovacs K, Pernicone PJ, Laws ER Jr: p53 expression in pituitary adenomas and carcinomas: correlation with invasiveness and tumor growth fractions. Neurosurgery 1996;38:765-770; discussion 770-771.
13.
Kaltsas GA, Nomikos P, Kontogeorgos G, Buchfelder M, Grossman AB: Clinical review: diagnosis and management of pituitary carcinomas. J Clin Endocrinol Metab 2005;90:3089-3099.
14.
Lim S, Shahinian H, Maya MM, Yong W, Heaney AP: Temozolomide: a novel treatment for pituitary carcinoma. Lancet Oncol 2006;7:518-520.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.