Breast - nonmalignant
Benign tumors / changes
Nipple adenoma / florid papillomatosis of nipple

Author: Hind Nassar, M.D. (see Authors page)

Revised: 9 August 2017, last major update April 2010

Copyright: (c) 2002-2017,, Inc.

PubMed Search: Nipple adenoma [title]

Nassar, H. Nipple adenoma / florid papillomatosis of nipple. website. Accessed August 21st, 2017.
Definition / general
  • Compact proliferation of small tubules lined by epithelial and myoepithelial cells, near collecting ducts of nipple
  • Rare; age 30 - 49 years
  • Variant of intraductal papilloma involving terminal portion of ducts
Clinical features
  • Benign
  • Unilateral, associated with serous / bloody nipple discharge
  • May clinically resemble Paget disease of nipple
  • May have associated carcinoma (Mod Pathol 1995;8:633) or metaplastic spindle cell lesions of variable malignancy (Mod Pathol 2003;16:893)
Case reports
  • Local excision; may recur if incompletely excised
Gross description
  • Ill defined nodule of nipple
Microscopic (histologic) description
  • Rounded outline of haphazard bilayered tubules in papillary pattern, often with fibrosis, continuous with squamous epithelium of epidermis
  • Peripheral clefting, oval nuclei, streaming
  • Epithelial hyperplasia and sclerosing adenosis types
  • May have keratin cysts or focal necrosis within proliferating ducts
  • Associated with bland cells in epidermis that are scattered or in small aggregates which are CAM 5.2+, CK7+, CEA-, HER2- (Am J Surg Pathol 1999;23:1349)
  • No atypia, no cribriform component
Microscopic (histologic) images

Images hosted on PathOut server:

Contributed by Dr. Mark R. Wick

With myoepithelial hyperplasia

Duct hyperplasia
w/ minimal sclerosis
at recent biopsy site

Epithelium without
atypia in dilated
(upper), duct
below nipple

Mixed pattern with
papilloma (upper),
sclerosis (center) and
adenosis (right side)

Focal necrosis in hyperplastic duct

Papillomatosis with adenosis

With DCIS and Paget disease (arrow) in adult man

Compact arrays of
ductules in adenosis
lesion beneath intact
nipple epidermis

With atypical
hyperplasia due to
disorderly growth
pattern without stroma

Images hosted on other servers:

Circumscribed and polypoid lesion

Proliferation of epithelial and myoepithelial cells

p63 shows intact myoepithelial layer

Patchy CK5 / 6 staining of myoepithelium

Negative stains
Differential diagnosis
  • Subareolar sclerosing duct hyperplasia: central sclerosis that entraps and distorts ducts, resembling radial scar
  • Syringomatous adenoma of nipple: haphazard proliferation of oval / elongated ductules and tubules composed of small basophilic cells infiltrating dermis of skin, nipple stroma and nipple smooth muscle bundles, resembling cutaneous syringoma; has desmoplastic stroma