SAT-106 - By Hook or by Crooke; Two Cases of A Rare Pituitary Tumor

Introduction
Pituitary Crooke’s cell adenomas (CCAs) are a rare subtype of corticotroph adenomas associated with Cushing’s disease, accounting for less than 1% of pituitary adenomas. CCAs can be functioning corticotroph adenomas, i.e., Cushing’s disease (CD), or clinically silent. Here we present two cases from our pituitary center.

Case #1
A 66 y/o M presented to the ED with polytrauma after MVA. CT brain showed incidental pituitary adenoma. Prior to the trauma patient denied any significant symptoms. Labs showed ACTH 60 pg/ml, AM cortisol with dexamethasone suppression test (DST) 2.6 mcg/dl. Normal 24-hour urine cortisol, salivary cortisol, Prolactin, IGF and Free T4. MRI showed heterogeneously enhancing pituitary macroadenoma expanding the sella and into suprasellar cistern with mild superior bowing of the optic chiasm measuring 2 x 2.3 x 1.8 cm. Underwent EEA resection with pathology confirming Corticotroph type, Crooke cell tumor. Empiric glucocorticoid coverage started for clinical concern of central adrenal insufficiency. Hence, cortisol nadir could not be obtained accurately. Post operatively developed CSF leak with lumbar drain, underwent a second EEA for revision of the nasoflap and a lumbopertoneal shunt placement. About 6 months after surgery was weaned off glucocorticoids with morning cortisol 12mcg/dl and ACTH 30 pg/ml with improvement in symptoms.

Case#2
A 63 y/o F presented to endocrinology clinic for management of Type 2 diabetes and pituitary macroadenoma. About 4 years prior tumor deemed nonfunctional based on biochemical evaluation. Repeat evaluation showed 24 hr urine cortisol 163.7 mcg/24h, salivary cortisol elevated twice (0.34mcg/dl and 0.18mcg/dl), AM Cortisol with 1 mg DST 6.2 mcg/dl and ACTH 74 pg/ml. MRI showed pituitary mass measuring 1.8 x 1.9 x 1.8 cm, expansion of the sella and effacement of suprasellar cistern. Mass encroached upon optic nerve with probable cavernous sinus invasion. Patient underwent transsphenoidal excision of pituitary adenoma. Pathology confirmed corticotroph type, Crooke cell variant. Postoperative course complicated by right cavernous ICA injury, which was repaired. There was concern for delayed remission evident with cortisol nadir of 3.8 mcg/dl. She later developed severe hypoglycemia during insulin adjustments and due to concern for glucocorticoid withdrawal was started on hydrocortisone 10mg BID. Also developed symptoms of partial central AVP deficiency and started on desmopressin 0.1 mg QHS. She will undergo repeat biochemical testing and MRI at 6 months postoperatively.

Discussion
Due to their rarity, CCA present a dilemma when assessing prognosis, treatment, and clinical management. Recurrence rate of 60% has been reported in literature and they may have poorer outcomes when compared to corticotroph adenomas. Hence, patients should undergo a strict clinical, radiological, and biochemical follow-up over time.

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