# Unilateral breast Darier disease: A case report and literature review

## TL;DR

A 35-year-old woman presented with a rare case of Darier disease affecting only one breast, leading to nipple destruction and non-tender skin lesions.

## Contribution

This case report highlights the unique presentation of unilateral breast Darier disease and its potential to be mistaken for other conditions like Paget's disease.

## Key findings

- Localized Darier disease can manifest as unilateral breast lesions with nipple destruction.
- The diagnosis was confirmed via biopsy showing acantholytic cells and papillary-like epidermal configuration.
- Literature review reveals prior cases of localized Darier disease in areas like the axilla and vulva.

## Abstract

Darier disease is often an underrecognized, disfiguring skin condition. Although the localized form of this condition has been reported in several parts of the body, the present study describes the case of a patient with the unique involvement of one breast, destroying the nipple. A 35-year-old female patient complained of having a right nipple lesion for 1 month. There were multiple small brown-to-black firm nipple lesions causing nipple destruction, associated with multiple small red, non-tender skin lesions in the areolar region and lower part of the breast. An incisional biopsy revealed a small number of acantholytic cells and a papillary-like configuration within the epidermis; no conclusive evidence of malignancy was observed, and a diagnosis of Darier disease was made. Emollient lotion, topical fusidic acid cream 2%, and oral isotretinoin 20 mg once daily were prescribed. The proposed pathogenesis of localized Darier disease is due to genetic mosaicism; these mutations arise during zygotic division. It can present as a rash with either macular or linear patterns confined to a specific body area. In the literature review, localized Darier disease affecting the inframammary region, vulva, axilla, and side of the abdomen have been reported, among others. Paget's disease was hidden in the background of Darier's disease of the breast in one of the cases in the literature. Darier disease may present as a localized unilateral breast lesion, characterized by multiple small, firm brown to black lesions on the nipple, leading to nipple destruction.