Infiltrating Syringomatous Adenoma of the Nipple
Definition
- Infiltrating subareolar neoplasm with small compressed duct-like structures
Alternate/Historical Names
- Syringomatous adenoma
- Syringomatous carcinoma
- Syringomatous tumor of the nipple
Diagnostic Criteria
- Located in dermis and subcutis of nipple and areola
- Infiltrating round to irregular tubules, often compressed and comma shaped
- Resembles syringoma
- Lumens may contain amorphous, eosinophilic material or keratin
- Infiltrates into smooth muscle bundles
- Perineural invasion may be present
- Myoepithelial cells present around tubules
- Results in a prominent expanded, at least double cell layer
- Squamous differentiation variable (5-80% of tubules)
- Superficial keratin filled cysts may be present
- Abundant desmoplastic collagenous stroma
- Bland cytology
- Mitotic figures rare
- No necrosis
- It has been proposed that this is the same lesion as low grade adenosquamous carcinoma of the breast differing only in location
- Adenosquamous carcinoma rarely may metastasize but this has not been reported for syringomatous adenoma
Richard L Kempson MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting: May 1, 2006
