Breast - nonmalignant
Adenosis
Sclerosing adenosis

Author: Jaya Ruth Asirvatham, M.B.B.S., M.D. (see Authors page)
Editor: Julie M. Jorns, M.D.

Revised: 2 August 2017, last major update January 2015

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

PubMed Search: Sclerosing adenosis [title] breast

Cite this page: Sclerosing adenosis. PathologyOutlines.com website. http://pathologyoutlines.com/topic/breastsclerosingadenosis.html. Accessed September 19th, 2017.
Definition / general
  • Low power diagnosis of increase in glandular elements plus stromal proliferation that distorts and compresses glands
  • Preservation of luminal epithelium and peripheral myoepithelium with surrounding basement membrane
Terminology
  • Adenosis tumor / nodular adenosis:
  • Myoepitheliosis:
    • Rare; sclerosing adenosis with predominance of myoepithelial cells, presents as multifocal microscopic lesions (Am J Surg Pathol 1991;15:554)
    • Cells may have longitudinal nuclear grooves
Epidemiology
Clinical features
Radiology description
  • Circumscribed to spiculated mass with architectural distortion
  • Amorphous or pleomorphic clustered microcalcifications
Case reports
Treatment
  • The presence of sclerosing adenosis alone in a core biopsy does not require surgical excision
Gross description
  • Multinodular, cuts with increased resistance
  • Gritty but no chalky yellow white foci or streaks
Microscopic (histologic) description
  • Low power diagnosis; increase in glandular elements plus stromal proliferation that distorts and compresses glands
  • Maintains lobular architecture at low power with rounded and well defined nodules
  • Centrally is more cellular with distorted and compressed ductules; peripherally has more dilated ductules
  • Often microcalcifications, apocrine metaplasia
  • Two cell layers are present but myoepithelial cells may vary from being prominent to indistinct
  • Also intralobular fibrosis, elastosis and apocrine metaplasia; florid changes are associated with pregnancy
  • Rarely penetrates walls of veins or perineural spaces
  • No necrosis, no pleomorphism
  • Epithelium may be involved by proliferative / atypical lesions or in situ carcinoma
  • Can mimic malignancy:
    • If nonlobulocentric / infiltrative into fat or stroma
    • Conspicuous myoepithelial cells with attenuated epithelial cells can appear like stands of single cells and mimic invasive lobular carcinoma
    • Atypical apocrine metaplasia: nuclear atypia / rare mitosis (Mod Pathol 1991;4:1)
    • Perineural invasion
Microscopic (histologic) images

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Images hosted on PathOut server:

AFIP images:

Fig 52: Ducts dilated at periphery

Fig 56 - 57: Small ducts with microcalcifications

Fig 70: Normal glands in upper right

Fig 58: Retention of
myoepithalial type
cells but loss of
ductal epithelium


Fig 59: Small bland ducts adjacent to nerve

Fig 53, 55: Intraductal papilloma

Fig 54: Invagination into cystic duct


Fig 194, 195, 197: With LCIS

Fig 198, 199: With LCIS and microinvasion (arrows)



Images hosted on other servers:

Low power


Small ducts with microcalcifications

Late stage; fibrosis and decreasing acini

Resembles microglandular adenosis

Myoid differentiation


Sclerosing adenosis at core biopsy in a 40 year old pregnant woman

In sentinel nodes


Various images

Adenosis tumor


SMMHC

Smooth muscle actin

CK14

Cytology description
Positive stains
Differential diagnosis