Breast - nonmalignant
Male tumors
Male papilloma

Author: Belinda Lategan, M.D. (see Authors page)

Revised: 31 August 2015, last major update August 2015

Copyright: (c) 2002-2015,, Inc.

PubMed Search: Male papilloma [title] breast
Definition / General
  • Morphologically and pathologically no different from papillomas in women
  • Incidence difficult to determine due to relatively few case reports, but deemed by most to be less common than in women due to structure and anatomy of male breast
  • Terminology
  • Central papilloma: occupies large lactiferous ducts, usually solitary
  • Peripheral papillomas: barring certain circumstances, proportionately less common in men
  • Sclerosing papilloma: stroma is densely collagnized and may be most prominent part of lesion, may entrap epithelial component and raise suspicion of malignancy
  • Papilloma with atypia (atypical intraductal papilloma): papilloma with ADH
  • Papilloma with DCIS: intraductal papilloma with DCIS (component of regular intraductal papilloma is still recognizable in the lesion)
  • Sites
  • Large lactiferous ducts: central papilloma (more common in male breast)
  • Smaller peripheral ducts: peripheral papilloma
  • Clinical Features
  • May present as bloody nipple discharge (thought to be due to tortion / infarction) or palpable mass
  • Any age (range 3 - 80 years based on case reports)
  • Diagnosis
  • Core needle biopsy, excision
  • Radiology images
  • Mass occupying a cystic space on imaging
  • Best recognized on Ultrasound
  • Prognostic Factors
  • Limited data
  • Presence of atypia
  • Case Reports
  • 14 year old boy with enlarging unilateral breast mass (J Pediatr Surg 2011;46:e33)
  • 44 year old man with benign intracystic papilloma of the breast (J Ultrasound Med 2008;27:1397)
  • 57 year old man with intracystic papilloma in the breast (Breast Cancer 2006;13:84)
  • Treatment
  • Complete excision constitutes cure and manages nipple discharge
  • As there is a relatively high incidence of carcinoma with papillary architecture in males, it is reasonable to excise all papillary lesions to rule out malignancy
  • Clinical Images
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    Palpable mass

    Gross Description
  • "Cauliflower" like mass in cystically dilated duct (larger central papillomas)
  • Mass with or without grossly recognizable papillary architecture
  • Micro Description
  • Benign proliferation of ductal epithelium supported by frond forming fibrovascular stroma, usually confined to a cystically dilated space / duct
  • Myoepithelial cells:
    • Line both fibrovascular cores and the duct occupied by the papilloma
    • Usually inconspicuous small bland spindled cells lining fibrovascular papillae and periphery of involved duct
    • Metaplastic changes include clearing of cytoplasm (must distinguish from pagetoid involvement by ALH / LCIS or carcinoma in situ)
    • If prominent / predominant myoepithelial component, the lesion may be termed myoepithelioma, which is considered by some to be within the spectrum and part of a continuum of papillary lesions
  • Epithelial lining cells:
    • One or multiple layers, may be hyperplastic with variably complex architecture and fill entire ductal space
    • Metaplasia is common, including apocrine (most common) and squamous (usually in setting of infarction)
    • Architectural and cytologic criteria for ADH and DCIS are similar to other proliferative epithelial lesions of the breast, but a size or percentage threshold exists
      • If low grade monotonous atypia: ADH if 1/3 or 30% (Tavassoli), ADH if <3 mm, but DCIS if 3 mm or more (WHO classification of tumours of the breast, 2012)
      • If intermediate to high grade atypia: DCIS regardless of quantity
    • Foci of atypia are usually negative for high molecular weight CK (CK5/6), but have strong and diffuse staining for ER
    • Pitfall: Apocrine metaplasia may lack high molecular weight CK staining but will be ER negative
  • Micro Images
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    Proliferation of ductal epithelium

    Missing Image

    Complex intraductal papilloma, AFIP

    Missing Image

    Papillary tumor, fibrovascular core, AFIP

    Positive Stains
  • Caveat: Always interpret IHC in context of H&E histology; metaplastic changes are common in papillomas
  • Myoepithelium: p63, SMMS-HC, SMA, calponin, S100, CD10
    • Should be identified lining fibrovascular cores and at periphery of involved ductal space
    • IHC may be difficult to interpret in papillomas with metaplasia, sclerosis and infarction
    • Especially at periphery of involved duct and in lesions with sclerosis or infarction, one marker alone may not reliably demonstrate myoepithelial layer due to attenuation of myoepithelial cells or cross reactivity with stromal cells
    • In addition, small vessels should not be interpreted as myoepithelial layer
    • As such, pay attention to the staining pattern expected for myoepithelial cells in order to avoid interpretive errors
    • Suggest using one nuclear marker (i.e. p63) and one cytoplasmic marker (SMMS-HC)
  • Epithelium: High molecular weight cytokeratins (i.e. CK5/6) expressed in mosaic pattern, ER variable indicative of benign proliferation
  • Atypical ductal hyperplasia (ADH) / low grade DCIS lacks CK5/6 expression and myoepithelium, and may display diffuse ER + (clonal) staining pattern
  • Columnar cell change in a papilloma may have CK5/6- / ER+ profile, which is not necessarily indicative of atypia, similarly apocrine metaplasia typically lacks ER expression
  • Electron Microscopy Description
  • Demonstrates epithelial vs myoepithelial differentiation of bilayered lining of fibrovascular cores
  • Differential Diagnosis