Indian Dermatology Online Journal

: 2018  |  Volume : 9  |  Issue : 3  |  Page : 218--219

Dermoscopy of cutaneous mastocytoma

Keshavmurthy A Adya, Arun C Inamadar, Aparna Palit 
 Department of Dermatology, Venereology and Leprosy, Shri B M Patil Medical College, Hospital and Research Center, BLDE University, Vijayapur, Karnataka, India

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

How to cite this article:
Adya KA, Inamadar AC, Palit A. Dermoscopy of cutaneous mastocytoma.Indian Dermatol Online J 2018;9:218-219

How to cite this URL:
Adya KA, Inamadar AC, Palit A. Dermoscopy of cutaneous mastocytoma. Indian Dermatol Online J [serial online] 2018 [cited 2022 Jan 24 ];9:218-219
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An 8-year-old boy presented with an episodically pruritic, dome-shaped, yellowish to skin-colored papule measuring approximately 6 mm × 5 mm on the right upper chest from the past 6 months [Figure 1]. Stroking the lesion with a blunt object produced a faint perilesional erythema without whealing. The lesion was completely excised, and hematoxylin-eosin analysis revealed diffuse dermal mononuclear cell infiltrate extending into and widening the dermal papillae [Figure 2]a. The cells stained positively with toluidine blue with metachromatic intracellular granules [Figure 2]b. The clinical and histological features were consistent with solitary cutaneous mastocytoma. Dermoscopy under polarized mode revealed a central whitish structureless area with a few reddish spots surrounded by reticulate brownish pigmentary networks on a yellowish background. The periphery of the lesion was formed by a reticulate hyperpigmented rim [Figure 3].{Figure 1}{Figure 2}{Figure 3}

Cutaneous mastocytoma usually occurs as a solitary lesion commonly involving the trunk, neck, and extremities of children. The onset is generally within the first few months of birth but late onset lesions are not infrequent. Typical lesions are yellowish-brown, smooth dome-shaped papules or nodules which may urticate on stroking (Darier's sign). Although a pathognomonic feature, the Darier's sign is seen only in half of the cases.[1] Vano-Galvan et al. delineated four predominant dermoscopic features in cutaneous lesions of mastocytosis which included light brown blot, pigment network (attributable to dermal mast cell infiltrate and basal layer hypermelanization ), and yellow-orange blot (attributed to dense papillary and reticular dermal mast cell infiltrate). Among these, the yellow-orange blot was consistently associated with mastocytoma.[2] In our case, the brown reticulate network on a background of yellowish hue was seen indicative of dense dermal mast cell infiltrate with increased melanization of the overlying basal layer of the epidermis, as evident in [Figure 2]a. The central pale yellow to whitish structureless area is caused by the accumulation of serosanguineous fluid produced due to excoriation of the epidermis in the centre of the lesion [Figure 1] because of scratching. The linear vessels and red spots in the centre correspond to dilated vessels seen prominently due to excoriation of the epidermis.

Differential diagnoses for such lesions in children include juvenile xanthogranuloma and papular or tuberous xanthomata. Juvenile xanthogranuloma is a close clinical differential diagnosis for mastocytoma. Dermoscopically as well, it exhibits yellow-orange blots, however, the color contrasts typically give a “setting sun” appearance. Additional features include fine interrupted brownish lines and peripheral vascular patterns.[3] Hence, dermoscopy is a useful investigative tool not only to support the clinical findings of cutaneous mastocytoma but also to differentiate from closer differentials such as juvenile xanthogranuloma.

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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2Vano-Galvan S, Alvarez-Twose I, De las Heras E, Morgado JM, Matito A, Sánchez-Muñoz L, et al. Dermoscopic features of skin lesions in patients with mastocytosis. Arch Dermatol 2011;147:932-40.
3Fernandes JR, Fernandes EL, Steiner D. Dermoscopic aspects of juvenile xanthogranuloma with multiple lesions. Surg Cosmet Dermatol 2016;8:256-8.