====== 1921 ======

[[1920]]-[[1922]]

The treatment of [[colloid cyst]]s has evolved rapidly since the first successful excision of a colloid cyst via the [[transcortical transventricular approach]] by Walter Dandy in [[1921]]
((Dandy WE. Benign tumors of the third ventricle. In: Thomas CC, editor. Diagnosis and Treatment. Springfield, Baltimore, IL: 1933.)).
This was followed closely by a [[transcallosal approach]] by Greenwood in [[1949]]
((Greenwood J., Jr Paraphysial cysts of the third ventricle; with report of eight cases. J Neurosurg. 1949;6:153–9.)).
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German physician Saemisch introduced compound lens magnication to medicine in [[1876]]. In the early part of the 20th century, Carl Nylen, a 30-year-old Swedish otolaryngologist, inspired by Maier and Lion’s observations of endolymph movement, conceived and built the world’s first operative microscope. In [[1921]] he used his monocular microscope for humans for the first time in a case of chronic otitis media. Gunnar Holmgren, Nylen’s chief at the Stockholm clinic, improved on Nylen’s monocular design and attached a light, creating the first binocular surgical microscope in [[1922]]. The original surgical microscopes were crude, usually requiring fixation to the bony structures of the skull
((Kriss TC, Kriss VM: History of the operating microscope: from magnifying glass to microneurosurgery legacy. Neurosurgery 42:899–908, 1998)).