Pituitary Crooke Cell Adenoma: Two Cases of an Aggressive Pituitary Adenoma.

Crooke cell adenoma (CCA) is a rare and aggressive subtype of a corticotroph adenoma, which requires lifetime surveillance. There have been 106 cases of CCAs reported in the English literature. We describe 2 cases of CCA, a 48-year-old man and an 84-year-old woman who both presented with binocular diplopia and temple pain. Neither case had clinical Cushing syndrome. Laboratory values for the 48-year-old man revealed, adrenocorticotropin (ACTH) 103 pg/mL (22 pmol/L) (RR: 7-63 pg/mL) and evening cortisol 14 µg/dL (386 nmol/L) (RR: 2.7-10.5 µg/dL). Computed tomography imaging demonstrated a mass adjacent to the right cavernous sinus extending into the sphenoid sinus. He underwent tumor resection with adjuvant radiation and has had a stable residual tumor for 4 years. Preoperative laboratory values for the 84-year-old woman revealed, ACTH 69 pg/mL (15 pmol/L) (RR: 7-63 pg/mL) and evening cortisol 16.2 µg/dL (447 nmol/L) (RR: 2.7-10.5 µg/dL). Brain magnetic resonance imaging revealed, a mass compressing the optic chiasm. She underwent resection and has had a stable residual tumor for 2 years. Surgical pathology in both cases revealed cytoplasmic hyaline deposits of more than 50% of the tumor cells, consistent with CCA. The CCA although rare, should be considered when evaluating cases with subclinical Cushing disease and visual symptoms.