Paget's disease of the breast

Paget's disease of the breast
Diagnosis in short
Paget's disease. H&E stain.
LM	large epithelioid cells - nested or single - in the epidermis, clear/pale cytoplasm (occasionally eosinophilic), large nucleoli
LM DDx	benign Toker cell hyperplasia, malignant melanoma, Bowen's disease, apocrine carcinoma of the skin
IHC	CK7 +ve, CEA +ve, S-100 -ve, CK5/6 -ve, HER2 +ve
Gross	erythema, +/-weeping, +/-crusted
Site	breast
Prognosis	usu. associated with invasive breast carcinoma
Clin. DDx	nipple adenoma, contact dermatitis

Paget's disease of the breast, also Paget disease of the breast and Paget's disease of the nipple, is a lesion of the breast. It is abbreviated PDB.

There is also a Paget's disease of the bone - just to make things confusing. This is dealt with in its own article and has nothing (from a pathologic perspective) to do with the Paget's disease discussed in this article; these two things just happened to be discovered by the same guy.

Non-bone Paget's disease is subdivided into:

1. Mammary Paget's disease - dealt with in this article.
2. Extramammary Paget's disease.

Histologically, i.e. under the microscope, the above are essentially identically; however, the associations (and prognosis) are quite different!

General

• Cells in the epithelium, i.e. skin, that look like they don't belong.
• Associated with underlying invasive breast carcinoma.

Note:

• Extramammary Paget's disease is not usually associated with malignancy.

Gross

Features:

• Erythematous, i.e. red.
• +/-Crusted.
• +/-Weeping (wet).

DDx - clinical:

• Contact dermatitis.

Images:

• Paget disease of the breast (sciencephoto.com).
• Paget disease of breast (medscape.com).

Microscopic

Features:

• Epitheliod morphology (round/ovoid).
• Cells nested or single.
• Clear/pale cytoplasm key feature - may also be eosinophilic.
• Large nucleoli.

Note:

• The neoplastic cells of Paget's disease may contain melanin.

DDx

• Benign Toker cell hyperplasia.
• Malignant melanoma.
• Bowen disease.
• Nipple (duct) adenoma (clinical DDx).
• Apocrine carcinoma of the skin.
  • Images: apocrine carcinoma - intermed. mag. (WC), apocrine carcinoma - high mag. (WC).

Images

• 

  Paget disease - low mag. (WC/Nephron)

• 

  Paget disease - high mag. (WC/Nephron)

• 

  Breast Paget Disease - high power - (SKB)

• 

  Breast Paget Disease - underlying invasive carcinoma - medium power - (SKB)

• 

  Breast Paget Disease - high power - (SKB)

• 

  Breast Paget Disease - high power - (SKB)

• 

  Breast Paget Disease - medium power - (SKB)

www:

• Paget disease of the breast - several good pictures (upmc.edu).
• Paget disease of the nipple (webpathology.com).

IHC

Panel:

• S-100 -ve, HMB-45 -ve (both typically +ve in melanoma).
• CK7 +ve. (???)
  • Toker cells CK7 +ve.
• CEA +ve (-ve in Bowen's disease, -ve in Toker cells).

Additional:

• HER2/neu - usually +ve.
• CK5/6 -ve.
  • Usu. +ve in squamous cell carcinoma.

Tabular comparison

IHC features of Paget disease and its DDx:

Entity	CK5/6	CK7	CAM5.2	EMA	CEA	HER2	S100	HMB-45
Paget disease	CK5/6 -ve	CK7 +ve (?)	CAM5.2 +ve	EMA +ve	CEA +ve	HER2 +ve	S100 -ve	HMB-45 -ve
Bowen disease	CK5/6 +ve	CK7 -ve	CAM5.2 -ve	EMA -ve	CEA -ve	HER2 -ve (?)	S100 -ve	HMB-45 -ve
Toker cell hyperplasia	CK5/6 ?	CK7 +ve	CAM5.2 ?	EMA +ve/-ve	CEA -ve	HER2 -ve	S100 -ve	HMB-45 ?
Melanoma	CK5/6 -ve	CK7 -ve	CAM5.2 -ve	EMA -ve	CEA -ve	HER2 -ve	S100 +ve	HMB-45 +ve

Mini-table comparison

Entity	CK7	CEA	HER2
Paget disease	CK7 +ve	CEA +ve	HER2 +ve
Toker cell hyperplasia	CK7 +ve	CEA -ve	HER2 -ve
Bowen disease	CK7 -ve	CEA -ve	HER2 -ve

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Right Nipple, Biopsy:
- Paget's disease.

Comment:
The Paget-like cells stain as follows:
POSITIVE: CK7 (moderate, diffuse), HER2 (complete membranous, moderate/strong).
NEGATIVE: S-100, HMB-45, CK5, CEA-mono.

The morphologic and immunohistochemical findings are in keeping with Paget's disease of the breast.

The breast imaging findings are noted.

See also

• Breast.
• Invasive breast cancer.
• Paget disease.
• Extramammary Paget disease.