Grynfeltt-Lesshaft hernia designates a superior lumbar triangle hernia, a quarter of which are of postincisional origin. It is a subtype of abdominal wall hernia that may be difficult to detect clinically or simulate other parietal masses, the diagnosis is usually posed by CT.

From the manuscript

Incarcerated Grynfeltt-Lesshaft Hernia

Abstract
Superior lumbar triangle hernia, also known as Grynfeltt-Lesshaft hernia, denotes a subtype of abdominal wall hernia, and more specifically of lumbar hernia, occurring between the 12th rib, the internal oblique muscle, and the quadratus lumborum muscle. We report the case of a 92-year-old female patient in which this form of hernia occurred, complicated by incarceration and acute bowel obstruction. The discussion contains a short résumé of the different kinds of abdominal wall hernias.