Category: Pituitary Disorders/Neuroendocrinology

Monitor: 31


Thursday, Apr 25
11:00 AM – 11:30 AM

Objective :

Crooke’s cell adenoma (CCA) of the pituitary is very rare with < 100 cases reported. CCAs usually present as invasive macrodenomas causing Cushing disease (> 75%) or as nonfunctional pituitary macroadenomas (< 25%). We report a de novo occurrence of CCA without hypercortisolism in a patient with known history of galactorrhea and hyperprolactinemia.

Methods : N/A

Results : A 46-year old woman was referred by her neurosurgeon for endocrine evaluation prior to pituitary surgery for a macroadenoma abutting the optic chiasm. She has a background history of hyperprolactinemia noted 8 yrs ago, preceded by recurrent bilateral nipple discharge Lt > Rt. Prolactin (PRL) was elevated, 38.7 ng/mL; sella MRI was negative. A repeat MRI 2 yrs later, revealed a T2 hyper- and T1 5 mm hypointense pituitary lesion consistent with a microadenoma. The cystic component was attributed to treatment, on cabergoline for > 2 yrs, later discontinued; PRL was normal. Sella MRI obtained 5 yrs later- Interval size increase of adenoma to 2 cm predominantly due to hemorrhage, blood products of varying ages, within 1 mm of the optic chiasm. A macroprolactinoma was suspected. Pituitary hormonal workup, including HPA axis testing and PRL assay (17.5 ng/mL) - Negative, except PRL dilution study > 1000 ng/mL. Visual field was normal. The patient declined dopamine agonist therapy and proceeded with surgery. Postoperative PRL was normal. However, histopathology was not consistent with a prolactinoma. The neoplasm demonstrated Crooke’s cells, architecturally and cytologically. Immunohistochemical staining demonstrated strong CK8/18, AE1/AE3 positivity with characteristic ACTH reactivity. There was no evidence of PRL positive cells.

Discussion :

Co-secretion of PRL and ACTH seemed unlikely in this patient. Preoperatively, this silent ACTH adenoma subtype of CCA masqueraded as a prolactinoma because of history of hyperprolactinemia and subsequently a questionable PRL dilution study suggestive of a “hook effect”. It was unlikely that a pituitary “stalk effect” would produce PRL of that magnitude. Although she had a history of recurrent galactorrhea and was previously hyperprolactinemic, based on a careful review of past records, we hypothesized that her prior PRL elevations could have been due to recurrent mastitis.

CCAs usually exhibit aggressive clinical behavior. Some clinical and radiological findings may suggest CCA, the final diagnosis is made based only on histopathological findings.

Conclusion : This de novo development of CCA, in a patient previously known to have an MRI negative pituitary gland in the setting of hyperprolactinemia, is the first reported case in the literature.


Samuel Olatunbosun

Chief of Endocrinology, David Grant USAF Medical Center, Travis AFB, CA
Uniformed Services University of the Health Sciences

Col (Dr.) Olatunbosun entered the Air Force through direct commissioning as a Medical Corps officer. He has served in various operational, command and staff positions that include Element Chief, Medical Director and Flight Commander. He first served as a staff physician at the 56th Medical Group Luke AFB, Arizona, subsequently appointed the Internal Medicine Medical Director and Element Chief. He was selected for a competitive DoD endocrinology fellowship position, with prior subspecialty training at Indiana University in 1994-1995. He earned the Fellowship of the American College of Endocrinology (FACE) distinction, earliest for any DoD endocrinologist. Colonel Olatunbosun distinguished himself as the Internal Medicine Subspecialties Flight Commander, 59th Medical Wing, Joint-Base San Antonio, Texas. He stood up and led the largest Air Force clinical subspecialties flight while personally providing patient care as the most productive endocrinologist.
Colonel Olatunbosun is a respected expert and educator, mentored 100+ physicians and medical students, with numerous publications in peer-reviewed journals, and he authored endocrine topics in widely used online clinical references. His areas of research interest include epidemiology and clinical aspects of diabetes mellitus, glucose intolerance, hypertension, obesity and insulin resistance; endocrine tumors, thyroid diseases and primary hyperparathyroidism. He has been an active member of AACE since 1994. Prior or current AACE activities include membership of the Publications Committee, the Health Care Disparities Committee, and the Disease State Networks (Diabetes; Nutrition and Obesity; Thyroid Disease).
He serves as an associate editor for an endocrine journal, editorial board member of 3 journals and as a reviewer for 10 top medical journals. He is a fellow of the American College of Physicians (FACP). Colonel Olatunbosun is an excellent graduate (2014) of the Air War College Distance Learning Program. He is currently the Chief of Endocrinology at the 60th Medical Group, Travis AFB, California.

Joseph McDermott

Staff Pathologist, Medical Director of Surgical Pathology
David Grant USAF Medical Center, Travis AFB

Not available

Joseph Kluesner

Staff Endocrinologist
David Grant USAF Medical Center, Travis AFB, CA

Not available

Narayana Swamy

Chief of Neurosurgery
Department of Veterans Affairs & David Grant USAF Medical Center, Travis AFB, CA

Not available

Alaaeldeen Elsayed von Bayreuth

Staff Pathologist, Associate Chief of Professional Staff
David Grant USAF Medical Center, Travis AFB, CA

Not available