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Year : 2019  |  Volume : 6  |  Issue : 1  |  Page : 57-59

An unusual case of unilateral nevoid acanthosis nigricans with dense lichenoid infiltrate

Department of Dermatology and Venereology, King Edward Memorial Hospital, Mumbai, Maharashtra, India

Date of Web Publication13-Jun-2019

Correspondence Address:
Vidya Kharkar
Department of Dermatology and Venereology, King Edward Memorial Hospital, Mumbai, Maharashtra
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijdpdd.ijdpdd_53_18

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How to cite this article:
Kumari I, Kharkar V. An unusual case of unilateral nevoid acanthosis nigricans with dense lichenoid infiltrate. Indian J Dermatopathol Diagn Dermatol 2019;6:57-9

How to cite this URL:
Kumari I, Kharkar V. An unusual case of unilateral nevoid acanthosis nigricans with dense lichenoid infiltrate. Indian J Dermatopathol Diagn Dermatol [serial online] 2019 [cited 2023 Mar 22];6:57-9. Available from: https://www.ijdpdd.com/text.asp?2019/6/1/57/260191


Unilateral nevoid acanthosis nigricans (UNAN) is a blaschkoid, linear, unilateral variant resembling epidermal nevus (EN) clinically and histopathologically.[1] There are very few, that is <40, case reports of UNAN so far. We report a case of symptomatic UNAN with unique presentation on histopathology.

A 15-year-old female presented with itchy, dark, and elevated lesions over and around the left areola extending to the left arm for 5 years. The lesions started at the nipple and extended to the arm over the period of 2–3 years, followed by a stable phase. On examination, severely pruritic, well-defined, hyperpigmented, velvety, and rounded plaques were present over the areola and periareolar region. Similar confluent linear plaques were also seen in linear fashion extending to the left axilla and arm with velvety and hyperpigmented background [Figure 1]. Asymptomatic velvety hyperpigmentation was also seen in the right axilla which was not noticed by the patient earlier [Figure 2]. A history of acneiform eruptions over the face was present for 3 years, with flare-up during menstruation. The patient was nonobese with body mass index of 23.5 kg/m2, regular and adequate menstrual cycle. There was no history of previous intake of any medication and other skin, scalp, nail, or mucosal lesions. No similar complaints or any history of endocrinal disorder was present in the family.
Figure 1: Linear velvety hyperpigmented and coalescent round-shaped plaques, distributed seen on left periareolar region extending to the arm

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Figure 2: Velvety hyperpigmentation present in the right axilla

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On investigations, hemogram, renal and liver function, thyroid hormones, cortisol levels, insulin levels, and blood glucose were within normal levels. Fasting blood sugar and serum insulin level were within the normal range of 98 mg/dl and 12.6 μg/ml, respectively. Homeostasis model of assessment of Insulin resistance (HOMA-IR) was 3.04 (<2.71 considered normal).[2] Ultrasonography of pelvis showed multiple ovarian cysts with a volume of 11.9 cc3 (right ovary) and 11 cc3 (left ovary) about polycystic ovarian disease (PCOD). Dermoscopic examination of the plaque revealed linear sulci and cristae, with black pigmentation in the sulci suggestive of acanthosis nigricans (AN) [Figure 3]. The histopathology of biopsy taken from the velvety plaque below the left axilla showed orthokeratosis, marked papillomatosis, increased pigmentation of the basal cells, and acanthosis. Dermis showed dense lichenoid infiltration in papillary dermis [Figure 4]. Other biopsy from the velvety pigmented area on the right axilla showed finger-like projections of dermal papillae and the valleys between the papillae filled with keratotic plug consistent with AN [Figure 5]. Considering unilateral blaschkoid but velvety appearance of the lesions with pubertal onset and dermoscopic and histopathologic features of AN, it was finally diagnosed as UNAN with unusual lichenoid infiltration on histopathology in a patient of PCOD (in view of acneiform eruptions, sonographic report, and AN in bilateral axillae). She was treated with both topicals (urea and lactic acid cream) and oral medication (metformin 500 mg twice daily).
Figure 3: Cristae and gyri with black dots more over gyri on dermoscopy (×200)

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Figure 4: Histopathology of the plaque showing hyperkeratosis, papillomatosis, acanthosis and lichenoid infiltrate in papillary dermis consistent with lichenoid (H and E, ×40)

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Figure 5: Histopathology showing orthohyperkeratosis, papillomatosis and acanthosis from velvety lesion at right axilla consistent with acanthosis nigricans (H and E, ×20)

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As proposed by Schwartz, AN is categorized into the eight types: benign, malignant, associated with obesity, syndromic, unilateral, drug induced, mixed, and acral.[1] UNAN has a morphology similar to classical AN, but is inherited as an irregularly autosomal dominant trait and the distribution is unilateral or blaschkoid. It can appear at birth, childhood, puberty, or in middle-aged adults, and several nonflexural locations have been reported: face, scalp, chest, abdomen, periumbilical area, back, and thigh. The natural history of the disease is a short period of progression for 4–5 years at the outset, followed by a stable phase which does not resolve as in our case.

Going back to literature, similar cases have been reported previously as AN like EN and rounded and velvety EN (RAVEN).[3],[4] The first reported case of unilateral epidermal nevus resembling AN was by Curth where a 32-year-old male patient had unilateral EN resembling AN since birth, began symmetrical AN at puberty and a mucoepidermoid cancer of the left parotid gland.[5] The case was later argued as type 2 segmental AN reflecting loss of heterozygosity at the FGFR3 locus in 2008.[6] In our case, we prefer to use the term UNAN both clinically and histopathologically considering more velvety, rather than keratotic consistency, mild compact hyperkeratosis, papillomatosis, and acanthosis. Diagnosis of inflammatory linear verrucous epidermal nevus (ILVEN) was not considered because of the absence of alternating broad parakeratosis and orthokeratosis with the absence of granular layer beneath it on histology. Lichenoid UNAN is not known so far. It is important to know about this variant because except few it is generally known not to be associated with endocrinopathy.[4] Even then careful search for internal diseases and syndromes should be done.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Das A, Bhattacharya S, Kumar P, Gayen T, Roy K, Das NK, et al. Unilateral nevoid acanthosis Nigricans: Uncommon variant of a common disease. Indian Dermatol Online J 2014;5:S40-3.  Back to cited text no. 1
Phiske MM. An approach to acanthosis Nigricans. Indian Dermatol Online J 2014;5:239-49.  Back to cited text no. 2
[PUBMED]  [Full text]  
Petit A, Lemarchand-Venencie F, Pinquier L, Lebbe C, Bourrat E. Nevoid acanthosis nigricans or RAVEN (rounded and velvety epidermal nevus): Three cases. Ann Dermatol Venereol 2012;139:183-8.  Back to cited text no. 3
Ersoy-Evans S, Sahin S, Mancini AJ, Paller AS, Guitart J. The acanthosis Nigricans form of epidermal nevus. J Am Acad Dermatol 2006;55:696-8.  Back to cited text no. 4
Curth HO. Unilateral epidermal naevus resembling acanthosis Nigricans. Br J Dermatol 1976;95:433-6.  Back to cited text no. 5
Happle R. Type 2 segmental acanthosis Nigricans: A historical case explained by a new concept. Arch Dermatol 2008;144:1637.  Back to cited text no. 6


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]


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