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
Original posting: May 1, 2006
Supplemental studies
Immunohistology
Myoepithelial layer present around tubules
Actin positive
S100 negative to sparse
Differential Diagnosis
Some consider these to be the same entity in different locations
Histologic appearance is identical
Small numbers of cases and differences due to superficiality could account for the difference in behavior reported
Tubular Carcinoma Infiltrating Syringomatous Adenoma of the Nipple
Uniform, gaping tubules
Irregular, frequently compressed lumens
Tubules frequently have pointed ends
Tubules frequently have long comma-shaped tails
No squamous differentiation
At least focal squamous differentiation
No myoepithelial component
Myoepithelial cells present around tubules
Clinical
Age 11-76, mean 46 years
Presents as subareolar mass
May have pain and nipple discharge
Size 0.5 to 3.5 cm
One case reported in male
Frequent recurrence if incompletely excised
No metastases reported
A single case has been reported of isolated keratin positive intravascular cells in a sentinel node removed following biopsy of the lesion
Lists
Lesions Preferentially Localized to the Nipple and Subareola
Breast Tumors and Lesions Exhibiting Reactivity for Muscle/Myoepithelial Markers
(Most benign lesions with an epithelial component will have a myoepithelial cell layer)
Bibliography
Rosen PP. Syringomatous adenoma of the nipple. Am J Surg Pathol. 1983 Dec;7(8):739-45.
Jones MW, Norris HJ, Snyder RC. Infiltrating syringomatous adenoma of the nipple. A clinical and pathological study of 11 cases. Am J Surg Pathol. 1989 Mar;13(3):197-201.
Carter E, Dyess DL. Infiltrating syringomatous adenoma of the nipple: a case report and 20-year retrospective review. Breast J. 2004 Sep-Oct;10(5):443-7.
Ward BE, Cooper PH, Subramony C. Syringomatous tumor of the nipple. Am J Clin Pathol. 1989 Nov;92(5):692-6.
Chang CK, Jacobs IA, Calilao G, Salti GI. Metastatic infiltrating syringomatous adenoma of the breast. Arch Pathol Lab Med. 2003 Mar;127(3):e155-6.
