location, location, location ......

76 year old man with a breast mass

Image 1: The lesion is circumscribed, and consists of epithelial structures evenly distributed in a myxoid stroma.  Some of the epithelial structures form clefts.

Image 3: As indicated for Image 2.

Image 2: Epithelial structures are associated with an eosinophilic ‘collarette’ in some areas, while other foci are surrounded by pale, myxoid stroma.

Image 4: Two groups of eccrine units at the top of the figure show this lesion to be present in the deep dermis/subcutaneous tissue and not breast proper.

Diagnosis:  Benign mixed tumor of skin appendageal origin (chondroid syringoma)

Discussion:  The submitting pathologist considered a diagnosis of fibroadenoma, although acknowledged that would be a rare diagnosis in a man.  The low power view showing a sharply circumscribed mass, with the clinical history of a breast mass, suggests that diagnosis.  Closer examination however shows stromal changes characteristic of benign mixed tumor (chondroid syringoma).  Moreover, the location within the dermis clinches the diagnosis.