Collagenous Spherulosis
Differential Diagnosis
| Adenoid Cystic Carcinoma |
Collagenous Spherulosis |
| Grossly visible or palpable lesion |
Nearly always an incidental microscopic finding |
| Invasive architecture |
Circumscribed, intraductal or intralobular |
| Uniform cores of basement membrane material |
Variable, frequently fibrillar spherules |
| Nuclei slightly enlarged compared to normal |
Nuclei identical in size and appearance to normal |
| CD117 positive lumenal cells |
CD117 negative |
| Calponin, smooth muscle myosin negative (even myoepithelial component) |
Calponin, smooth muscle myosin positive |
Both contain myoepithelial and epithelial components
| Cribriform Carcinoma |
Collagenous Spherulosis |
| Grossly visible or palpable lesion |
Nearly always an incidental microscopic finding |
| Invasive architecture |
Circumscribed, intraductal or intralobular |
| May have intralumenal mucin but lacks fibrillar or laminated appearance |
Frequently fibrillar or laminated spherules |
| Lacks myoepithelial component |
Myoepithelial cells surround spherules |
| Nuclei slightly enlarged compared to normal (2-3 times larger than RBC) |
Nuclei identical in size and appearance to normal |
| Cribriform Ductal Carcinoma In Situ |
Collagenous Spherulosis |
| May have intralumenal mucin but lacks fibrillar or laminated appearance |
Frequently fibrillar or laminated spherules |
| Myoepithelial component restricted to peripheral layer of duct |
Myoepithelial cells surround spherules |
| Nuclei slightly enlarged compared to normal (2-3 times larger than RBC) |
Nuclei identical in size and appearance to normal |
