Clinically Silent Adrenocorticotropic Hormone-Secreting Crooke Cell Adenoma Presenting as Unilateral Ear Pain

ABSTRACT Objective: Crooke cell adenoma (CCA) is a rare tumor of the anterior pituitary. It is highly aggressive and carries significant risk of morbidity and mortality. Methods: This report focuses on the presentation of this disease process and review diagnosis and treatment. The patient is a 64-year-old male with a history of resected pituitary adenoma of unknown pathology. Results: The patient underwent serial magnetic resonance imaging surveillance for numerous years without recurrence of tumor, however eventually developed symptoms of worsening left ear pain over 3 weeks that rapidly evolved to include ptosis. Imaging revealed a new pituitary macroadenoma. Urgent surgical resection revealed histopathological diagnosis of CCA. Corticotroph adenomas represent a rare subset of pituitary tumors. Clinically silent pituitary tumors demonstrate relatively higher rates of cavernous sinus invasion (30% versus 18%) and progression or recurrence (34% versus 6%) when compared to nonfunctioning adenomas. In CCA, only 65% of patients have clinical features of Cushing disease at presentation. Twenty-four-hour urinary free cortisol is discussed in the literature as a potential tool, where a value 4 times the upper limit of normal was predictive of higher risk of having Crooke cell changes. With a recurrence rate of up to 60%, multimodal treatment (surgery and radiation) is preferred. Conclusion: This case highlights early detection and treatment as keys to reducing the risk of morbidity and mortality from CCA. Currently, there are limited tools for identifying patients who are high risk for developing Crooke cell changes. Treatment modalities classically include surgery and radiotherapy. Adjuvant and novel chemotherapies are being explored. Abbreviations: ACTH = adrenocorticotropic hormone; CCA = Crooke cell adenoma; MRI = magnetic resonance imaging