Atypical ductal hyperplasia

Breast - nonmalignant
Atypical hyperplasia
Atypical ductal hyperplasia

Author: Jaya Ruth Asirvatham, M.B.B.S.

Senior Author: Julie M. Jorns, M.D.

Topic Completed: 1 October 2014

Revised: 30 May 2019

Copyright: 2002-2019, PathologyOutlines.com, Inc.

PubMed Search: Atypical ductal hyperplasia [title] breast

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Table of Contents

Cite this page: Asirvatham JR Atypical ductal hyperplasia. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/breastadh.html. Accessed July 18th, 2019.

Definition / general

Neoplastic intraductal lesion with architectural and cytological features suggestive but not diagnostic of low grade DCIS

Terminology

Also called DIN 1B, atypical intraductal hyperplasia (AIDH), mammary intraepithelial neoplasia (MIN)

Epidemiology

May be present in women as young as 18 - 26 years (Am J Surg Pathol 1992;16:246)
Rates have decreased over past decade, possibly due to significant reduction in use of postmenopausal hormonal therapy (Cancer Epidemiol Biomarkers Prev 2009;18:2822)

Etiology

Atypical ductal hyperplasia (ADH) and coexisting cancers may arise independently in field of increased cancer risk, as genetic changes (at 1q and 16q) are not identical (J Pathol 2006;209:307)

Clinical features

There are no clinical features associated with ADH

Radiology description

No definite diagnostic features
On mammography, lesions may be identified as masses, asymmetric densities, microcalcifications and architectural distortions
On ultrasound, lesions appear as hypoechoic masses with irregular shape, microlobulated margins, abrupt interface
Underestimation rate of ADH is high (56% by mammograph / USG and 32% by MRI) (AJR Am J Roentgenol 2014;202:1389, AJR Am J Roentgenol 2014;203:682)

Prognostic features (for carcinoma)

Relative risk of carcinoma is 4 - 5x; lower risk if 0 - 2 foci at core biopsy (see below)
Early studies suggested a 10x relative risk if positive family history of breast cancer but newer studies find no such increase (Cancer Prev Res (Phila) 2014;7:211)
Estimated 10 year cancer risk is 17 - 26% (Breast Cancer Res Treat 2012;136:627)
There is a 2:1 ratio of ipsilateral to contralateral breast cancer, with higher ipsilateral risk within the first five years (Cancer Prev Res (Phila) 2014;7:211)
Risk for breast cancer is higher for younger women and those with multiple foci of ADH
Mean time from atypia to carcinoma diagnosis is 10.3 years
25% develop DCIS, 75% develop invasive carcinoma
76% of carcinomas are ductal, 8.5% are lobular; 75% are node negative
2/3 are moderate or high grade

Treatment

ADH at core biopsy: excision recommended since associated with DCIS and invasive carcinoma, particularly if target lesion is not completely excised (Am J Surg Pathol 2002;26:1095)
- DCIS found in 12 - 36% of excision specimens
- Invasive carcinoma found up to 14% of excision specimens
- Additional foci of ADH found in 25% of excision specimens
Same recommendations pertain to 11 gauge (Ann Surg Oncol 2007;14:2497) or 9 gauge needles (AJR Am J Roentgenol 2007;188:684)
Page found no worse lesion at excision if ADH limited to 0 - 2 foci at core biopsy (Am J Surg Pathol 2001;25:1017) but other studies have found malignancy in 12% of these cases (Radiology 2010;255:723)
ADH at margin: reexcision is controversial, recommended by some since 25% may have DCIS or invasive carcinoma at reexcision (Ann Surg Oncol 2008;15:843)
In the NSABP trial, women with atypia receiving tamoxifen had a 75% reduction of risk in breast cancer at 7 years (Breast Cancer (Dove Med Press) 2014;6:29)

Microscopic (histologic) description

Usually less than 2 - 3 mm, may be multicentric
Must rule out DCIS (Breast Cancer Res 2003;5:254)
Micropapillae, tufts, bridges, solid and cribriform patterns of evenly distributed, monomorphic cells with rounded or ovoid nuclei
Either closely mixed with epithelial ductal hyperplasia (without atypia) or only partially involving the terminal duct lobular unit
Perineural invasion is rare and usually associated with sclerosing adenosis or radial scar (Hum Pathol 2001;32:785)
Variable microcalcifications
Recommended to include size of lesion in surgical pathology report
Either (1), (2) or (3) AND no high grade cytology (Stanford University: Atypical Ductal Hyperplasia):
1. Ducts are completely filled and exhibit sharp punched out spaces or micropapillae but lack uniform cytologic features due to partial population of columnar cells or focal streaming of cells
2. Ducts filled by uniform population of cells with cytologic features of low grade DCIS but lack architectural features due to only partial filling of ducts or no uniformly sharp punched out spaces, microacini or characteristic micropapillae AND have excluded solid low grade DCIS
3. Cytologic and architectural features of DCIS but lesion is too small (fewer than two duct spaces involved or less than 2 - 3 mm in aggregate dimension)*
* Differentiation of ADH and low grade DCIS based on size cutoffs is controversial due to lack of expert agreement

Microscopic (histologic) images

AFIP images

Cells don't stream and are haphazardly
arranged in cellular bridges with
mitotic activity (arrows) but
secondary lumina are irregular

Cells have uniform size and shape,
small foci of necrosis and calficiation
but secondary lumina are irregular
and more numerous at periphery

Uniform cells but irregular secondary lumina

Papillary proliferation of multilayered epithelium involving only part of duct

Rounded secon-dary lumens and heterogenous cell population

Ducts are lined by
crowded, hyperplastic,
tall columnar cells
forming small papillae

Contributed by Dr. Mark R. Wick

Contributed by Dr. Marilin Rosa

ADH involving areas of sclerosing adenosis in complex sclerosing lesion

Images hosted on other servers:

Irregular glandular spaces

Enlarged, irregular, hyperchromatic nuclei

Solid filling of a duct

Atypical cells quite homogeneous

Micropapillary and cribriform pattern

Nuclei are crowded and hyperchromatic

Similar architecture seen in DCIS

Nuclei are crowded and overlapping

Proliferating epithelium are rigid and "punched out"

Nuclei are haphazardly arranged

Cribriform type

Micropapillary type

Cribriform type, high power

Cells are irregularly arranged

Cell margins are indistinct

Usual ductal hyperplasia (CK903+) versus ADH (CK903-)

Virtual slides

Images hosted on other servers:

ALH and ADH involving a fibroadenoma

ADH, papillary lesions

Cytology description

Three dimensional cells with uniform nuclei and occasional mild atypia

Cytology images

Images hosted on other servers:

Ductal lavage

Positive stains

CK8 / 18

Negative stains

Only 10% of ADH express high molecular weight keratins (34betaE12, CK903) - useful in differentiation from UDH (100% positive)
Usually negative for CK5 / 6
Usually negative for HER2 (10% positive, Mod Pathol 1990;3:449)

Differential diagnosis

Columnar cell lesion: prominent apical cytoplasmic snouts and intraluminal secretions
Flat epithelial atypia: replacement of epithelial cells by single or stratified layer of cells with low grade cytologic atypia resembling low grade DCIS but does not fulfill criteria of ADH or low grade DCIS
Low grade DCIS: larger lesion involving entire terminal duct lobular unit, uniform cells, no secondary lumina
Usual ductal hyperplasia: mix of cell types (luminal, basal, myoepithelial) that express different cytokeratins (note that because ADH is clonal, CK expression is restricted to one type, usually luminal)