Paget disease of breast
It is widely accepted that MPD is nearly always associated with underlying breast carcinoma. Malignant cells from the underlying ductal adenocarcinoma invade the nipple unit and overlying peri-areolar skin. The malignant cells spread through the normal epidermis in "pagetoid fashion," admixed among normal keratinocytes.
Only 1%-4% of breast carcinoma presents with MPD, but nearly 100% of MPD is associated with an underlying breast carcinoma (ductal carcinoma in situ [10%] or infiltrating carcinoma [90%]).
The malignant cells of MPD express the same apomucins, and possess the chromosomal aberrations, of the underlying breast cancer. The condition is detected on biopsy using the same immunohistochemical stains employed in breast carcinoma, such as cytokeratin 7.
Treatment requires referral to a breast oncologist and oncologic surgeon for evaluation to detect and manage the underlying breast carcinoma.
Related topics: Breast cancer, Cutaneous breast cancer
C50.019 – Malignant neoplasm of nipple and areola, unspecified female breast
403946000 – Paget's disease of nipple
Differential Diagnosis & Pitfalls
- Nipple eczema – Eczematous eruption of the nipples with weeping, crusting, and painful fissuring, seen especially in nursing mothers.
- Erosive adenomatosis of the nipple (papillary adenoma) – A rare, benign neoplasm of the lactiferous ducts that is often mistaken for nipple eczema in early stages and for MPD in later stages.
- Benign Toker cell hyperplasia – An extremely unusual condition where normal Toker cells of the breast tissue, particularly of supernumerary nipple, are hyperplastic but lack the malignant qualities of MPD.
- Squamous cell carcinoma in situ – May assume an eczematous-appearing plaque of the nipple and peri-areolar skin, but the condition is derived from malignant keratinocytes.
- Melanoma in situ – May also assume a pagetoid configuration in the epidermis of the nipple and peri-areolar skin, but the condition is derived from malignant melanocytes.
- Sebaceous carcinoma – May also derive a pagetoid configuration in the epidermis of the nipple and peri-areolar skin, but the condition is derived from malignant sebocytes.
- Clear cell acanthoma
- Hyperkeratosis of the nipple and areola