Lennox became Head Surgeon at Charing Cross Hospital, London, and later a well-known Harley Street surgeon. He did pioneer research and provided hormonal therapy and surgery for intersex patients, especially those with adreno-genital syndrome (now known as Congenital adrenal hyperplasia), at Charing Cross Hospital in the 1930s and 1940s.
In 1932 he devised an operation which provided heretofore-impossible access to the adrenal gland for removal of tumours.
Unlike the other surgeons who operated on intersex and 'transvestite' patients in the 1930s and 1940s, e.g. Harold Gillies, Kurt Warnekros, Ludwig Levy-Lenz, Erwin Gohrbandt, Milosh Kilcka, he did not do just one or two as an experiment, but did several hundred operations over the years.
He later worked with John Randell. Patients included: Mark Weston.
He died in Wimbledon, London, aged 77.
- L. R. Broster, Clifford Allen, H. W. C. Vines, Jocelyn Patterson, Alan W. Greenwood, G. F. Marrian, and G. C. Butler. The Adrenal Cortex and Intersexuality. London: Chapman & Hall Ltd., 1938. 245 pp.
- “Were Once Sisters”. The News of the World. 2 Aug 1943.
- Dave King. “Pioneers of Transgendering: John Randell, 1918-1982”. University of Ulster: Gendys Conference, 2002. www.gender.org.uk/conf/2002/king22.htm.
- "The Broster Family Connection". Family Trees, History and Stories. http://genealogy.amay.co.uk/main.php?p=FF2-broster.