Cabot&;s ring is seen in-

In the peripheral blood smear of megaloblastic anaemia . Cabot rings are thin, threadlike, red to violet rings or "figure 8" shaped inclusions in red blood cells. Cabot rings are remnants of the mitotic spindle, and can be seen in megaloblastic anemia, medication effect, myelodysplasia and other forms of dyserythropoiesis. reference :textbook of Pathology, 7th edition ,Author Harsha Mohan ,page number 283, figure 10.20