Dermoscopy of hyperkeratosis of the nipple and areola

Sir, Hyperkeratosis of the nipple and areola (nevoid/primary hyperkeratosis of the nipple and areola, NHNA/HNA) is a rare benign dermatosis, characterized by a verrucous appearance of the nipple and areola, associated with cosmetic concerns in patients. There is a scarcity of reports on the dermoscopy of this entity. We report a case of NHNA diagnosed based on the clinical, dermoscopic, and histopathological findings. A 22-year-old female presented to us with complaints of asymptomatic dark-colored raised lesions over both nipples for the past 2 years. There was no history of discharge from the nipple. She denied a history of similar lesions in the past and the use of topical medication before the development of lesions. General and systemic examination was unremarkable. On cutaneous examination, there were brownish-black verrucous plaques without erythema and induration that hindered the visibility of bilateral nipples (Fig. 1). There was no tenderness, discharge, or lymphadenopathy. Rest of the cutaneous examination was normal. Dermoscopy of lesions was performed using DermLite DL4 (Polarized mode, 10x magnification, USA) with the help of Oneplus 5 (48 MP) camera, which revealed keratotic, structureless, brown-gray angulated clods (Fig. 2a-b), suggestive of HNA. Later on, a punch excisional biopsy was performed from the margin of the lesion suggestive of the thickened epidermis with filiform acanthosis and papillomatosis with basal hyperpigmentation, which corresponds with the dermoscopic findings (Fig. 2c-d). Based on the aforementioned findings, a diagnosis of NHNA was reached. She was treated with emollient and fluticasone propionate 0.05% cream once daily application and showed a significant response at the end of 4 weeks of therapy (Fig. 3).Figure 1: Brownish-black verrucous plaques without erythema and induration that hindered the visibility of bilateral nipples (a, b).Figure 2: a-d: Dermoscopy (polarized mode, 10x magnification) of the lesion revealed keratotic, structureless, brown-gray angulated clods (yellow star) with a whitish papillomatous surface at places (red circle). (a, b) Histopathology revealed thickened epidermis with filiform acanthosis, papillomatosis with basal hyperpigmentation, and suugestive of hyperkeratosis of the nipple and areola (H and E 10×: c; 40×: d).Figure 3: a-b: Significant response at the end of 4 weeks of therapy (a, b).Hyperkeratosis of the nipple and areola is a rare benign condition first described by Tauber in 1923. It remains controversial whether HNA is a distinct entity or a clinical presentation of other dermatoses. A study conducted by Obayashi H found that 80% of cases were women in the age group of 20–40 years. It has been found that it may not necessarily only appear in females during puberty or pregnancy but also in males using diethylstilbestrol for prostate carcinoma treatment or as a result of hormonal disorders. It can be unilateral or bilateral and focal or diffuse. It occurs bilaterally affecting the nipple and areola in most of the cases accounting for 70% of the cases [1]. The typical clinical features are persistent verrucous thickening and pigmentation with an absence of induration or oozing, as seen in our case. Based on the Levy-Frankel classification (1938), HNA is classified into three types. Type 1 (associated with epidermal nevus), type 2 (associated with various dermatoses such as Darier disease, chronic eczema, acanthosis nigricans, ichthyosis, lymphoma, etc), and type 3 (idiopathic or unknown etiology) [1,2]. Based on this classification, our case falls under the type 3 group HNA. Recently, in 2001 Mehanna et al. also classified HNA into three types: type 1is associated with hormonal factors and systemic diseases, type 2 is considered an idiopathic form, and type 3 is coincidentally associated with keratinization disorders such as ichthyosis, Darier disease, etc. Based on this classification, our case belonged to type 2 [3]. Ozturkcan S et al.[4] were the first to describe dermoscopy in 2015 as keratotic, structureless, brown-gray angulated clods in a 13-year-old female, as seen in our case. There is a paucity of literature on the dermoscopy of this entity (Table 1). The differential diagnoses are acanthosis nigricans, seborrheic keratosis, epidermal nevus, wart, and rarely Paget's disease, melanoma, etc. There is no consensus available on the treatment of this condition. However, various modalities such as topical corticosteroids, topical tacalcitol, topical keratolytics, retinoids, cryotherapy, radiofrequency ablation, fractional lasers, and surgical excision have been tried in managing the disease. We report this case because of its rarity and the importance of the role of dermoscopy to differentiate it from other conditions. Table 1 - Review of literature on dermoscopy of hyperkeratosis of the nipple and areola Sr.no Authors Age/sex Diagnosis Dermoscopy 1 Ozturkcan S et al. (2015)[4] 13/F NHNA keratotic, structureless, brown-grey angulated clods 2. Mazzella et al. (2016)[5] 30/F NHNA mimicking pigmented BCC Multiple blue-grey globules and leaf-like areas. 3. Cinnotti et al. (2018)[6] 24/F NHNA Papillomatous surface with pink homogenous whitish desquamation, red dots or erosions. 4 Muñoz-Aceituno E et al. (2019)[7] 12/F Focal NHNA Whitish papillomatous surface with brown hyperkeratotic deposits within ridges. 5 Dash S et al. (2021)[8] 25/M HNA secondary to Darier disease Central crater filled with yellow to yellowish-brown keratotic plugs surrounded by white radial streaks, brown homogenous areas and pigment network. 6. Claudio C et al. (2022)[9] 27/F NHNA Homogenous brown network with some hyperkeratotic areas showing yellow-brown scale. 7. Our case 22/F NHNA keratotic, structureless, brown-grey angulated clods with whitish papillomatous surface at places Acknowledgements Source(s) of support: None. Presentation at a meeting: Nil. Organization Place Date Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.