Collagenous Spherulosis
Definition
- Breast lesion composed of intralumenal clusters of spherules
Alternate/Historical Names
- Mucinous spherulosis
- Spherulosis
Diagnostic Criteria
- Intralumenal process
- Partially fills terminal ducts or acini
- Aggregate of acellular eosinophilic spherules imparts a cribriform appearance
- 20-100 microns diameter
- Few to 50 spherules per section of lesion
- Usually discrete but may coalesce
- Basophilic, mucinous variant has been reported
- Spherules show fibrillar structure, usually concentric or with radial spikes
- Other patterns
- Hollow with eosinophilic cuticle
- Hyaline eosinophlic granules, 1-2 microns
- May have associated microcalcification
- Other patterns
- Cellular component is mixed epithelial and myoepithelial
- Myoepithelial cells surround spherules and whole lesion
- Small round cytologically bland cells
- Identical in size and appearance to normal duct lining cells
- No mitotic figures
- Nearly always an incidental microscopic finding
- Usually confined to one medium or high power field
- Two cases reported 2-3 mm diameter
- May be multifocal
- One case reported to be palpable
- May be biopsied because of associated microcalcifications
- Usually confined to one medium or high power field
Richard L Kempson MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting:: December 23, 2006