Pituitary Stalk Lesion Sampling by Transsphenoidal Posterior Lobe Biopsy: A Case Series.

Objective This study aims to assess the safety and efficacy of performing posterior lobe pituitary biopsy in patients with pituitary stalk lesions compared to direct stalk biopsy. Design We performed a single-institution retrospective review of four patients who underwent ETSS of the posterior pituitary lobe for a lesion of the pituitary stalk without clear diagnosis, despite non-invasive workup. Participants Four patients with known pituitary stalk lesions who underwent posterior pituitary biopsy without tumor resection. Main Outcome Measures The main outcomes were post-procedural endocrine function across all axes compared to preoperative function, post-procedural morbidities and ability to obtain an accurate histologic diagnosis from biopsy. Results 100% (4/4) patients were histologically diagnosed based on tissue from transsphenoidal biopsy of the posterior lobe. There was no worsening of pre-operative endocrine function. One patient experienced a CSF leak. There were no other postoperative complications. None of the patients experienced worsening of vision attributable to biopsy. Conclusions Transsphenoidal posterior lobe biopsy has a low risk profile and high diagnostic capacity in patients presenting with a lesion of the pituitary stalk of uncertain etiology.