Image Description
Microscopic Features - Fibrous Hamartoma of Infancy (FHI): About 25% of cases of FHI have hyalizined collagenous areas with cracking artifact forming slit-like spaces lined by flattened tumor cells. This creates a pseudoangiomatous appearance reminiscent of giant cell fibroblastoma. However, FHI lacks PDGFRB rearrangements, unlike giant cell fibroblastoma. Note the primitive mesenchymal component on the right and mature adipose tissue to the left in this image.