Cellular fibroadenoma

Breast - nonmalignant
Benign tumors / changes
Cellular fibroadenoma of breast

Author: Monika Roychowdhury, M.D., Hind Nassar, M.D. (see Authors page)
Editorial Board review: Emily S. Reisenbichler, M.D.

Revised: 2 June 2017, last major update March 2017

Copyright: (c) 2003-2017, PathologyOutlines.com, Inc.

PubMed Search: Cellular (juvenile) fibroadenoma of breast

Table of Contents

Cite this page: Cellular fibroadenoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/breastfibroadenomacellular.html. Accessed July 14th, 2017.

Definition / general

Resembles fibroadenoma with pericanalicular pattern but more cellular

Essential features

Fibroadenoma (stromal and epithelial process) with uniform epithelial and stromal hypercellularity but lacking leaf-like pattern of phyllodes tumor
No atypical features, i.e. no periductal stromal condensation, no cytologic atypia, no mitotic figures > 3/10 HPF
Excision is curative

Terminology

Also called juvenile fibroadenoma
Giant fibroadenoma: terminology used inconsistently; refers to size, often children, but not a distinct histopathologic entity

Epidemiology

Usually black females, median age 15 years (range 10 - 39 years)

Clinical features

Grows rapidly but benign behavior
Often massive size
Either solitary or multiple / successive lesions; recurrences usually cease in 20's
Not associated with subsequent carcinoma

Case reports

12 year old premenarche girl with bilateral, rapidly enlarging breast lumps (Pathology Research International 2011;2011:1)
15 year old girl with bilateral tumors (National Institute of Oncology and Radiobiology, Cuba)
18 year old post pubertal girl presented with bilateral, rapidly enlarging breast lumps (Sch J App Med Sci 2016;4:1830)

Treatment

Conservative excision (preserve as much normal breast tissue as possible, Saudi Med J 2007;28:137, Breast J 2000;6:418)

Gross description

Yellowish tan, softer than classic fibroadenoma

Gross images

Images hosted on other servers:

Well circumscribed
lobulated mass

Microscopic (histologic) description

Resembles fibroadenoma with pericanalicular pattern, may be mixed with intracanalicular pattern
- Uniformly hypercellular stroma, no atypical features; i.e. no periductal increase in cellularity, no stromal overgrowth, no cytologic atypia, no mitotic figures > 3/10 HPF
- Frequently epithelial as well as myoepithelial hyperplasia
Stromal and epithelial balance is not altered; lacks leaf-like growth pattern
Epithelium may have tufted pattern or hyperplasia characteristic of gynecomastia; may have epithelial atypia (Am J Surg Pathol 1987;11:184)
No increase in periductal cellularity that is seen in phyllodes tumors

Microscopic (histologic) images

Images hosted on other servers:

Juvenile fibroadenoma

Juvenile fibroadenoma - stromal and epithelial hyperplasia

Mitosis - infrequent finding

Fibroepithelial tumor with florid intraductal epithelial hyperplasia

(Myo)fibroblastic stroma, duct with columnar epithelium

Positive calponin

p63

Cytology images

Images hosted on other servers:

Monolayered sheets of ductal cells

Monolayered sheets of epithelial cells

Differential diagnosis

Hamartoma: more abundant adipose tissue; epithelial component is more disorganized
Phyllodes tumor: prominent stromal overgrowth, intracanalicular growth pattern, periductal concentration of cells, variable atypia and mitotic figures

Additional references

Arch Pathol Lab Med 1987;111:427, Stanford University, Am J Clin Pathol 2014;142:362

Board review question #1

Which feature supports a diagnosis of phyllodes tumor over cellular fibroadenoma?

A. Pericanalicular pattern
B. Young patient
C. Periductal condensation of stromal cells
D. Epithelial tufting or hyperplasia

Board review answer #1

C. Features supporting a diagnosis of phyllodes tumor over cellular fibroadenoma are an older patient, intracanalicular pattern with leaf like formations, periductal condensation of stromal cells, cytologic atypia and increased mitotic activity