Unusual clinical presentation of a crooke cell adenoma – a rare and aggressive pituitary adenoma variant

Abstract

Pituitary adenomas are common intracranial neoplasms, making up approximately 15% of all intracranial tumours.1 The clinically non-functioning pituitary adenomas that show hormonal or transcription factor production on immunohistochemistry are termed ‘silent’. Crooke cell adenoma (CCA) is one of the recently defined high-risk pituitary adenoma subtypes and comprises 4% of corticotroph adenomas.2 Most patients with CCAs present with Cushing's disease, however, there are rare cases of silent CCAs reported in the literature. We present a case of silent CCA in a 65-year-old female who presented with headache and vertigo. Histopathology of the resected macroadenoma showed characteristic immunohistochemical and ultrastructural findings. Pathologists should be aware of the diagnostic criteria for CCA regardless of the tumour’s functional status due to the high recurrence rates of CCA after transsphenoidal resection.3 1.Drummond J, Roncaroli F, Grossman AB, et al. Clinical and pathological aspects of silent pituitary adenomas. J Clin Endocrinol Metab 2019; 104: 2473–89.2.Lloyd RV, Osamura RY, Klöppel G, et al., editors. WHO Classification of Tumours of Endocrine Organs. 4th ed. Lyon: IARC, 2017.3.George D, Scheithauer B, Kovacs K, et al. Crooke’s cell adenoma of the pituitary: an aggressive variant of corticotroph adenoma. Am J Surg Pathol 2003; 27: 1330–6.