Dermoscopic Features of Different Forms of Cutaneous Mastocytosis: A Systematic Review

Abstract

The term mastocytosis refers to a heterogeneous group of disorders characterised by accumulation of clonal mast cells in different organs, most commonly in the skin. Little is known about the role of dermoscopy in the diagnostics of mastocytosis. To date, no systematic review on the dermoscopic features of cutaneous mastocytosis has been performed. The aim of this study was to summarise the current knowledge in the field as well as to identify the knowledge gaps to show possible directions for further studies, based on a systematic search of PubMed, Scopus, and Web of Science databases and related references published before 3 January 2022. Dermoscopic features, type of dermoscope, polarisation mode, magnification, and number of cases were analysed. In total, 16 articles were included in this review (3 case series and 13 case reports), analysing 148 patients with different variants of cutaneous mastocytosis; all of the studies analysed had a low level of evidence (V). The main dermoscopic features of urticaria pigmentosa included brown structureless areas, brown lines arranged in a network, and linear vessels distributed in a reticular pattern, with this last finding also being typical of telangiectasia macularis eruptiva perstans. The presence of either circumscribed yellow structureless areas or diffuse yellowish background was a constant pattern of mastocytoma, while nodular, pseudoangiomatous xanthelasmoid, and plaque-type mastocytosis were typified by light-brown structureless areas and/or pigment network, though the first two variants also showed yellow/yellow-orange structureless areas. Finally, pigmented streaks of radial distribution surrounding hair follicles were described to be a pathognomonic dermoscopic feature of pseudoxanthomatous mastocytosis. Although this review shows that the various clinical forms of cutaneous mastocytosis may feature diagnostic dermoscopic clues, it also underlines the need for further investigation as several relevant data are missing, including evaluation of dermoscopic pattern according to anatomical locations or “lesion age”, studies on rare mastocytosis variants, evaluation of the prognostic role of dermoscopy in the context of systemic involvement, and comparative analyses with common clinical mimickers.

Updates in diagnosis and management of paediatric mastocytosis

“…Cutaneous mastocytosis presents in children with well demarcated macular brown skin lesions associated with the Darier's sign (a major criterion) and one or two minor criteria from the following, increased mast cells in lesional skin biopsy, and an activating mutation in KIT from lesional skin [12]. Darier's sign consists of erythema and urticaria swelling of the lesion when stroked.…”

Urticaria pigmentosa and systemic mastocytosis

“…UP usually presents as localized, monomorphic, tan‐brown maculopapular lesion that can urticate when mechanically agitated. However, UP may take on a variety of clinical appearances, 4 sometimes presenting as ill‐defined reddish brown macules with associated telangiectasias (termed ‘telangiectasia macularis eruptiva perstans’), caused by the perivascular infiltration of atypical neoplastic mast cells around dermal capillaries. 5 These atypical presentations can often be misdiagnosed as telangiectatic disorders, such as scleroderma, hereditary hemorrhagic telangiectasia or telangiectasias secondary to cirrhosis, but their clinical outcome is indistinguishable from classical UP, despite the difference in macroscopic appearance.…”

Diffuse Cutaneous Mastocytosis: A Rare Entity and its Dermoscopic Features

“…In the literature, dermoscopic features have been described in MPCM, localized mastocytoma, and other rare variants, however, there is paucity of data on dermoscopy of classical DCM, probably due to the rare occurrence of the disease. [ 1 ] In the urticaria pigmentosa subtype, brown reticular lines, light brown blots, and pigment network were seen which correspond to increased proliferation of melanocytes and increased melanin production induced by mast cell growth factors. [ 2 3 ] In telangiectasia macularis eruptiva perstans (TMEP) subtype reticular vascular pattern, erythematous/brownish background, and fine pigment network were seen.…”

“…[ 2 3 ] In telangiectasia macularis eruptiva perstans (TMEP) subtype reticular vascular pattern, erythematous/brownish background, and fine pigment network were seen. [ 1 ] In mastocytoma, yellow structureless areas on a yellow background were seen indicating compact mast cell infiltration of the dermis. Brown structureless areas correspond histologically to basal cell hyperpigmentation in mastocytosis while vascular patterns denote dermal vessel dilatation.…”

“…Brown structureless areas correspond histologically to basal cell hyperpigmentation in mastocytosis while vascular patterns denote dermal vessel dilatation. [ 1 ] Another interesting case report of a rare variant “pseudoangiomatous xanthelasmoid mastocytosis” on dermoscopy also showed a brown reticular pattern and yellow blots. [ 4 ]…”