Wong-Type Dermatomyositis Showing Porokeratosis-Like Changes (Columnar Dyskeratosis): A Case Report and Review of the Literature

Abstract

Background: Wong-type dermatomyositis (DM) exhibits simultaneous pityriasis rubra pilaris (PRP) features.

Case report: A 50-year-old woman presented with a heliotrope rash, Gottron's papules, and a poikilodermic, erythematous rash in shawl distribution without evidence of muscle weakness. Despite topical corticosteroids, the eruption progressed 9 months later to include generalized hyperkeratotic follicular papules, islands of sparing, and atrophic macules with a collarette of scale suggestive of porokeratosis. Mild dysphonia was the only sign of muscle weakness. Serology showed positive ANA. Histopathology revealed interface dermatitis with dermal mucin and melanophages, irregular psoriasiform hyperplasia, alternating mounds of para- and orthokeratosis, and tiers of dyskeratotic cells (columnar dyskeratosis). Systemic corticosteroid therapy was not tolerated; acitretin diminished the hyperkeratosis. While hyperpigmentation persisted, no progression of cutaneous or muscular symptoms has occurred after 22 months of follow-up and cessation of the therapy. Overall, her course did not differ from the natural history documented in the literature review of Wong-type DM. The most similar case also exhibited pseudocornoid lamella changes.

Conclusion: Wong-type DM is a clinicopathologic DM-PRP hybrid that can also exhibit porokeratosis-like features best described as columnar dyskeratosis. Recognizing these types of lesions in DM is warranted in order to make an accurate assessment of their prognostic significance.

Keywords: Columnar dyskeratosis; Dermatomyositis; Pityriasis rubra pilaris; Porokeratosis; Wong type.

Fig. 1

Clinical presentation of Wong-type DM with porokeratosis-like changes. The top left panel shows a diffuse hyperpigmented plaque and keratotic follicular papules (inset). The bottom left panel highlights confluent patches and plaques of coarse, dirty grayish, hyperkeratotic skin with areas of dull-pink discoloration as well as islands of sparing. The top right panel demonstrates Gottron's papules over the phalangeal-metacarpal and interphalangeal joints as well as numerous markedly keratotic papules over the dorsal hands and forearms. The bottom right panel shows, within the regions of generalized hyperkeratosis, scattered hypopigmented lesions with a collarette of fine scale reminiscent of porokeratosis.

Fig. 2

Concomitant histopathology of DM and PRP. The top left panel shows the characteristic changes of DM consisting of vacuolar interface alterations, numerous melanophages, free melanin in the papillary dermis, cytoid bodies, and necrotic keratinocytes; in the bottom left panel, abundant mucin deposition is visible. The top and bottom right panels show histopathologic findings of PRP with irregular psoriasiform hyperplasia, alternating mounds of para- and orthokeratosis, follicular plugging, and an intact granular layer.

Fig. 3

Pseudocornoid lamella (columnar dyskeratosis). The top panel shows numerous, fine collarettes of scale at the edges and overlying keratotic papules suggestive of porokeratosis. However, microscopically, typical cornoid lamellae were not present. The bottom left and right panels show epidermal dells plugged by dyskeratotic (necrotic), parakeratotic, and orthokeratotic keratinocytes arranged vertically rather than diagonally, as found in typical lesions of porokeratosis [19]. At the dermoepidermal junction, focal vacuolar interface changes are present, which are associated with necrotic keratinocytes and colloid bodies. Overlying these regions are discontinuous tiers of mostly dyskeratotic cells (highlighted by the brackets). This constellation of findings best matches a recently described disorder termed ‘columnar dyskeratosis’ [16].