Syringocystadenoma papilliferum has almost identical central characteristics. Compared with the hidradenoma papilliferum, it has a more dense plasma cell infiltrate and has an attachment to the overlying epidermis, which usually manifests as an invagination of the epidermis into the tumor lobule.
Treatment: A complete excision is diagnostic and curative at the same time. Often, a biopsy is performed to ascertain the diagnosis, followed by the curative complete excision. These are rare and benign tumors. There have been reports of malignant degeneration, but this is exceedingly rare.