https://immattersacp.org/archives/2012/09/mksap.htm

MKSAP Quiz: Mildly pruritic eruption on a woman's right nipple


A 55-year-old woman is seen in follow-up for a mildly pruritic eruption on and surrounding her right nipple, which developed about 5 months ago. Triamcino-lone acetonide cream was begun 1 month ago, but since then there has been no improvement in the lesion. She has no personal or family history of eczema or psoriasis, and she is otherwise healthy. Her only medication is triamcinolone.

Breast findings are shown.

MKSAP image c American College of Physicians Medical Knowledge Self-Assessment Program
MKSAP image (c) American College of Physicians Medical Knowledge Self-Assessment Program

Which of the following is the most likely diagnosis?

A. Chronic cutaneous lupus erythematosus
B. Lichen simplex chronicus
C. Paget disease of the breast
D. Psoriasis

Reveal the Answer

Answer and critique

The correct answer is C: Paget disease of the breast. This question can be found in MKSAP 15 in the Dermatology section, item 40.

This patient has Paget disease of the breast, defined as a persistent, scaling, eczematous, or ulcerated lesion involving the nipple/areolar complex. This disease is actually an extension of an underlying ductal adenocarcinoma of the breast that may be present even in the absence of abnormal physical examination findings or mammogram. It is often misdiagnosed on the first presentation as either eczema or psoriasis, but when there is a lack of response to appropriate therapy a biopsy should be performed.

The most characteristic lesions of chronic cutaneous lupus erythematosus are discoid lesions (erythematous, infiltrated plaques that are covered with scale and are associated with follicular plugging). These lesions are most often found on the face, neck and scalp. As they expand, they develop depressed central scars. This patient's lesion is not clinically compatible with chronic cutaneous lupus.

Lichen simplex chronicus is a localized disorder characterized by intense pruritus, which leads to a localized area of lichenified skin (thickened skin with increased and exaggerated skin markings due to scratching). This patient has no evidence of lichenification.

The most common form of psoriasis is plaque psoriasis. The skin lesions of this disorder are sharply demarcated, erythematous plaques covered by silvery-white scales that affect the scalp and extensor surfaces (elbows and knees) as well as the nails. A single patch of psoriasis located on the nipple would be a very rare presentation.

Key Point

  • Paget disease of the breast presents as a persistent, scaling, eczematous, or ulcerated lesion involving the nipple/areolar complex and may be mistaken for more benign conditions such as eczema.