Breast - nonmalignant
Tubular 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 December 2014

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

PubMed Search: Tubular adenosis breast

Cite this page: Tubular adenosis. website. Accessed November 21st, 2018.
Definition / general
  • Very rare benign breast lesion of haphazard, elongated tubules that are narrow and noncrowded
  • May mimic invasive carcinoma or coexist with invasive or in situ carcinoma (Am J Surg Pathol 1996;20:46)
  • Coined by Oberman in 1983 (Am J Surg Pathol 1996;20:46) to identify a rare benign lesion that could potentially be mistaken for invasive carcinoma
  • Usually ages 40 - 82 years
  • Benign lesion, premalignant potential yet to be determined
Clinical features
  • Can present as a mass; produced exclusively by tubular adenosis or in association with DCIS or invasive ductal carcinoma
  • Can be incidental
Case reports
Microscopic (histologic) description
  • Overall architecture is haphazard, with elongated branching tubules in different directions, at most vaguely lobulocentric
  • Some tubules extend into fat and mimic carcinoma; however suspicious tubules between normal lobular units are not seen
  • Tubules are generally blunt with occasional angular contours
  • Lumina may be slit-like and collapsed or dilated
  • In cross section, the tubules have a round profile, superficially resembling microglandular adenosis
  • Tubules are lined by bland ductal cells with a myoepithelial layer
  • Tubules contain basophilic or eosinophilic secretions (which may be colloid-like) and microcalcifications
  • Stroma may be sclerotic, cellular or edematous
  • Mitoses are absent
Microscopic (histologic) images

Images hosted on PathOut server:

AFIP: mildly irregular tubules within stroma

AFIP: tubules appear to branch in 3 dimensions

Two cell layers

Images hosted on other servers:

Features of collagenous spherulosis

Differential diagnosis