Endocrine Abstracts

Introduction: Crooke’s cell adenomas (CCA) are a rare type of pituitary neoplasm, associated with Cushing’s disease. They are characterised by accumulation of perinuclear cytokeratin filaments, appearing distinctly hyaline in hematoxylin and eosin (HE) staining (Crooke’s hyaline change). Due to their rarity, the management and treatment remain a challenge.

Clinical case: A 33-year-old male patient, presented sudden visual impairment, no signs of Cushing’s disease were reported. The pituitary MRI revealed a 51×29×32mm macroadenoma within sella turcica, penetrating into the cavernous sinus, suprasellar region and the third ventricle with compression of the optic chiasm. Two months after the initial diagnosis, the typical hypercortisolemia symptoms (sudden weight gain, striae and hypertension) occurred. The laboratory results showed high ACTH concentrations (230pg/ml), loss of circadian cortisol rhythm, elevated urinary free cortisol excretion (UFC 675 mg/24 h), and lack of cortisol inhibition after 1 mg of dexamethasone. The patient underwent transsphenoidal surgery, the mass was partially (~50%) removed (diameters of mass 19x14x12mm in MRI) without normalisation of ACTH and UFC. After the post operation period, gradual increases of cortisol hormones and tumor mass progression were observed. After analyzing the risk associated with reoperation or possible radiation therapy, the decision was made to start with conservative treatment. Regarding the presence of functional Cushing disease, long-acting pasireotide administered once monthly was introduced, with the initial dose of 10 mg with gradual titration to 30 mg. However, the normalisation of ACTH and UFC after 6 months of treatment was not achieved. For the next 6 months osilodrostat (1 mg twice a day) was added to the therapy simultaneous with pasireotide 30 mg each month. In imaging data, a year after the pharmacology therapy, the slight progression in tumor size was detected (diameters of mass 22x15x20mm). Another attempt at transnasal resection was made, but no complete resection was achieved. Postoperatively the normalisation of UFC was observed with persistent slight increase of ACTH concentration (150pg/ml). Histologically, the tumour was described as densely granulated adenoma, Ki-67 labeling index was low; surprisingly no Crooke hyaline change was detected. Again, the therapy of pasireotide was restarted with stabilisation of the disease (UFC in normal laboratory range 54.6 mg/24 h and slight increase of ACTH concentration 135pg/ml) after one year of observation.

Conclusion: CCA is a rare pituitary adenoma that should receive significant attention. Pasireotide could be considered as a second or third line treatment in CCA. However, further studies of the effectiveness of such treatment are required.