Cabot rings

Cabot rings are thin, red-violet staining, threadlike strands in the shape of a loop or figure-8 that are found on rare occasions in erythrocytes. They are believed to be microtubules that are remnants from a mitotic spindle.

Cabot rings have been observed in a handful of cases in patients with megaloblastic anemia, lead poisoning and other disorders of erythropoiesis. They were first described in 1903 by American physician, Richard Clarke Cabot (1868-1939).