Breast - nonmalignant
General
Thelarche

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

Revised: 21 July 2017, last major update June 2014

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

PubMed Search: Thelarche [title] breast

Cite this page: Thelarche. PathologyOutlines.com website. http://pathologyoutlines.com/topic/breastthelarche.html. Accessed November 21st, 2017.
Definition / general
  • Rapid growth of breasts at onset of puberty, usually age 10 - 11 in females
  • Signifies entry into Tanner stage II of development
  • Growth is due to fat deposition, periductal connective tissue expansion and the elongation, branching and thickening of ductal system with development of terminal duct lobular units; growth may be sporadic
  • Influenced by estrogens, growth hormone and prolactin but not progesterone
Drawings

Images hosted on other servers:

Tanner staging:

Stage I: preadolescent

Stage II: breast budding (thelarche)

Stage III: enlargement of areolar diameter

Stage IV: areola / papilla
form secondary mound
with separation of contours

Stage V: mature female breasts

Clinical features
  • Premature thelarche: onset prior to age 8 in girls with normal BMI in general population
  • Although similar processes lead to breast development in males, gynecomastia is the preferred term and not thelarche
Radiology images

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Missing Image

Various images

Prognostic factors / pathologic factors
  • Excision of initial subareolar disc will lead to amastia after puberty
  • Earlier onset of thelarche and longer interval between thelarche and menarche may be associated with increased breast cancer risk (Breast Cancer Res 2014;16:R18)
  • Premature if prior to 8 - 9 years; may be isolated or part of precocious (central) puberty if other signs of puberty are present; lacks lobules (BMC Pediatr 2008;8:27)
  • Premature thelarche associated with increased BMI and non-Hispanic black and Mexican American ethnicity (Pediatrics 2009;123:84)
  • No tests currently predict risk of progression to precocious puberty in premature thelarche (J Pediatr 2010;156:466)
Case reports
Clinical images

Images hosted on other servers:

Premature thelarche

Gross description
  • Rubbery subareolar discoid mass; may be asymmetric
Microscopic (histologic) description
  • Prior to puberty, breasts of both sexes have ducts with variable branching lined by cuboidal epithelium, no lobules and no necrosis
  • At puberty in females, lobules develop
  • Breast tissue in premature thelarche resembles gynecomastia with epithelial hyperplasia in ductal system in a solid or micropapillary configuration
Microscopic (histologic) images

Images hosted on PathOut server:

Premature thelarche (9 year old girl with premature breast enlargement):

AFIP: proliferation of ducts
without lobules; intraductal
epithelial hyperplasia with
uniform cells and prominent nuclei