Indian Dermatology Online Journal

: 2019  |  Volume : 10  |  Issue : 3  |  Page : 360--362

Dermoscopy of keratoacanthoma centrifugum marginatum

Keshavmurthy A Adya1, Arun C Inamadar1, Aparna Palit2,  
1 Department of Dermatology, Venereology and Leprosy, Shri B M Patil Medical College, Hospital and Research Center, BLDE (Deemed to be) University, Vijayapur, Karnataka, India
2 Department of Dermatology and Venereology, All India Institute of Medical Sciences, Bhubaneswar, Odisha, India

Correspondence Address:
Arun C Inamadar
Department of Dermatology, Venereology and Leprosy, Shri B M Patil Medical College, Hospital and Research Center, BLDE (Deemed to be) University, Vijayapur - 586 103, Karnataka

How to cite this article:
Adya KA, Inamadar AC, Palit A. Dermoscopy of keratoacanthoma centrifugum marginatum.Indian Dermatol Online J 2019;10:360-362

How to cite this URL:
Adya KA, Inamadar AC, Palit A. Dermoscopy of keratoacanthoma centrifugum marginatum. Indian Dermatol Online J [serial online] 2019 [cited 2020 Jun 4 ];10:360-362
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Full Text

A 50-year-old male presented with a 6-month-old growth on the left upper thigh. The lesion had begun as a small reddish papule that evolved into a large lobulated mass in a few months with central resolution and peripheral extension. The lesion regressed over time, but a part of it persisted at the periphery. Examination revealed an 8 × 4 cm atrophic depigmented patch with marginal hyperpigmented rim and specks of hyperpigmentation within. A 1.5 × 1 cm dome-shaped pinkish nodule topped with yellowish thick scales and a similar 1 × 1 cm lesion without scaling were noted near the margins of the patch [Figure 1].{Figure 1}

Dermoscopy of the scaly nodule revealed central thick yellowish-white scales (keratin) surrounded by multiple grayish-white circles, lines, and structureless zones on a pinkish background. The grayish-white circles were seen surrounding central whitish structure. Also noted were the red globules interspersed with the whitish zones [Figure 2]a. Dermoscopy of the non-scaly nodule revealed multiple whitish globules and lines on an erythematous background [Figure 2]b. On dermoscopy, the hyperpigmented margin revealed multiple dark globules and irregular pigment network, and the atrophic region showed milky white area interspersed with fine telangiectatic vessels [Figure 3].{Figure 2}{Figure 3}

Biopsy from the nodule with scaling revealed large invaginating masses of well-differentiated keratinocytes with overlying compact orthokeratotic hyperkeratosis, hypergranulosis, and acanthosis. Also noted were acanthosis and hypergranulosis of the epithelium of a dilated follicular infundibulum [Figure 4]. The clinical and histological features were characteristic of keratoacanthoma (centrifugum marginatum type).{Figure 4}

A typical keratoacanthoma is a rapidly enlarging solitary papule that evolves into a circumscribed crateriform nodule with a keratotic plug within a few weeks, and then gradually involutes over months to leave behind an atrophic scar. Most of the lesions affect the elderly and involve the sun-exposed areas. Several other clinical forms including keratoacanthoma centrifugum marginatum are described as well. The latter is a rare type characterized by progressive peripheral growth with central clearing. Histopathologically, keratoacanthoma shows a crateriform pattern with an endoexophytic proliferation of normal keratinocytes. In the growing phase, invaginating masses of keratinocytes are seen with a keratin-filled crater. In regressing lesions, a prominent central keratin plug with “lipping” or “buttressing” of the edges of the lesion over the central crater is typical.[1],[2]

Rosendahl et al. characterized keratin, surface scales, white circles, white structureless zones, and blood spots as dermoscopic criteria common to keratoacanthoma and squamous cell carcinoma (SCC) by retrospective analysis of 60 cases of invasive SCC and 43 cases of keratoacanthoma. After statistically re-evaluating the significance of these criteria with 206 non-pigmented raised lesions, they concluded that the keratin, white circles, and blood spots serve as useful clues to differentiate SCC and keratoacanthoma from other raised non-pigmented lesions. Keratin had the highest sensitivity, and white circles showed highest specificity for keratoacanthoma and SCC.[3] The dermoscopic–histopathologic correlation in our case [Figure 5] was in concordance with those delineated by Rosendahl et al. [Table 1].{Figure 5}{Table 1}

The role of dermoscopy in keratoacanthoma appears to be mostly limited to differentiate it, together with SCC, from other raised non-pigmented lesions based on findings like keratin, white circles, and blood spots. Although not absolutely specific to SCC and keratoacanthoma, the significance of these findings lies in the fact that they were found to occur much more frequently in these two lesions. Hence, their presence in any raised non-pigmented skin lesion should prompt a biopsy. Although central keratin was shown to be more common in keratoacanthoma than in SCC, unequivocal differentiation between the two is not possible with dermoscopy alone and requires correlation with clinical and histological findings.[3]

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

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1Soyer HP, Rigel DS, Wurm EMT. Actinic keratosis, basal cell carcinoma and squamous cell carcinoma. In: Bolognia JL, Jorizzo JL, Schaffer JV, editors. Dermatology. 3rd ed. London: Elsevier; 2012. pp 1773-93.
2Weedon D. Tumors of the epidermis. In: Weedon D, editor. Weedon's Skin Pathology. 3rd ed. Edinburgh: Churchill Livingstone Elsevier; 2010. pp 668-708.
3Rosendahl C, Cameron A, Argenziano G, Zalaudek I, Tschandl P, Kittler H. Dermoscopy of squamous cell carcinoma and keratoacanthoma. Arch Dermatol 2012;148:1386-92.