Bone marrow histology showing prefibrotic stage of PMF

Bone marrow histology (Giemsa stain) showing the prefibrotic stage of PMF (also called CIMF). Capillaries and fibroblasts have a stringy appearance (lower part of the picture). In the upper third the haematopoietic tissue still looks normal. The highlighted megakaryocyte (->) is atypical.