Hyperkeratosis of nipple and areola
HNA may be primary or occur secondary to the presence of a seborrheic keratosis or epidermal nevus, or as part of an underlying dermatosis such as Darier disease, acanthosis nigricans, atopic dermatitis, inherited ichthyoses (eg, ichthyosis vulgaris), or confluent and reticulated papillomatosis of Gougerot and Carteaud (CARP). Some cases have been ascribed to medications (estrogens, spironolactone, and vemurafenib).
HNA is seen in both sexes, but the majority of cases have been reported in postpubescent females, mainly those in their second to third decade of life. To date, there have been approximately 150 cases reported in the literature, but it is highly likely that this condition is underreported. A single case has been reported in a prepubescent girl.
Pathophysiology of primary HNA is unclear, although the occurrence of HNA mostly in female patients after puberty, its worsening in pregnancy with improvement post-delivery, and its occurrence in patients on estrogen therapy suggest an underlying hormonal pathogenesis.
N64.59 – Other signs and symptoms in breast
403459000 – Hyperkeratosis of nipple
Differential Diagnosis & Pitfalls
- Acanthosis nigricans – look for similar involvement of flexural areas and an association with metabolic disorders or underlying malignancy
- Seborrheic keratosis – this diagnosis is more likely if papillomatous papules are well-defined and discrete
- Epidermal nevus – onset in early infancy or childhood; usually unilateral and spreads beyond area of areola; frequently follows Blaschko linear pattern
- Mycosis fungoides
- Terra firma-forme dermatosis – areas of skin changes are easily removed by isopropyl alcohol
- Nipple eczema
- Erosive adenomatosis of the nipple – onset usually in the fifth decade of life; presents as an itchy, burning, subareolar, ulcerated, and/or crusted nodule
- Paget disease of the breast – will have positive cytokeratin 7 (CK7), carcinoembryonic antigen (CEA), estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2/neu) immunohistochemical staining
- Bowen disease – has propensity for sun exposed areas
- Breast carcinoma
- Basal cell carcinoma (eg, pigmented basal cell carcinoma)
- Physiological changes of pregnancy
Drug Reaction Data