Fibrous Hamartoma of Infancy : Differential

Comments:
Differential Diagnosis of Fibrous Hamartoma of Infancy (FHI) (continued from the previous image): For FHI with a dominant fibroblastic component, the differential diagnosis includes:

Desmoid-type Fibromatosis: Rare in young children; long, sweeping fascicles of band fibroblastic cells; nuclear staining with β-catenin; mutations of CTNNB1 gene.

Diffuse Myofibromatosis: Consists of hemangiopericytomatous vascular spaces separating lightly-staining nodules.

Calcifying Aponeurotic Fibroma: Located in distal portion of the extremities in older children; calcified and chondroid-appearing nodules surrounded by epithelioid cells; presence of FN1-EGF fusion.

The image shows classic triphasic appearance of FHI. The differential diagnosis continues in the next image.