Sir Victor Horsley (1857-1916) undertook removal via the transcranial route of pituitary tumours which represent the earliest attempts at pituitary surgery. This work formed part of his body of surgical practice which embraced several key innovations including in the treatment of trigeminal neuralgia and the development of the Horsley-Clarke stereotactic frame.

The author describes the climate of surgical and endocrine practice in which Horsley began this work with reference to the pituitary, his craniotomy technique, and the results of treatment. The primary source was Horsley’s case books and postmortem records, archived at the National Hospital, Queen Square, London. Records were identified for patients with a diagnosis of a pituitary tumour admitted between 1886 and 1916 and treated surgically. Contemporary records of non-pituitary cases were also examined.

He carried out a craniectomy for removal of a pituitary tumour via the subtemporal approach between 1904 and 1907 in four patients. These patients all presented with significant impairments of visual fields or visual acuity; one patient had severe trigeminal neuralgia. Evidence of acutely raised intracranial pressure was present in one patient. All patients underwent craniectomy under chloroform anesthesia. One patient died on the day of surgery, and the postmortem findings are presented. In the other three patients, neurological morbidity was recorded in the postoperative period in the form of new cranial nerve deficits, monoparesis with dysphasia, and seizures. The patient with trigeminal neuralgia experienced partial relief and was readmitted later for reexploration and Gasserian ganglionectomy via the same route. Contemporary nonoperative cases of pituitary tumor are also presented. These cases provide significant insight into the presentation and operative treatment of pituitary tumours during the pre-Halsted era, and into Horsley's operative technique.