Linear atrophoderma of Moulin: A rare case report and review of the literature

Abstract

Linear atrophoderma of Moulin (LAM) is an uncommon dermatological disease characterised by linear, depressed plaques typically following Blaschko's lines. LAM generally occurs in adolescence or early adulthood and is more commonly observed in females. The aetiology of LAM is still unclear. We report a rare case of LAM in an 18-year-old female presenting with an atypical Blaschkoid distribution (multiple band-like pattern) on her right trunk. A clinical examination and histopathological analysis were performed to make the diagnosis. Partial improvement was obtained with calcipotriol and colchicine. LAM is a rare condition; we were only able to identify 23 case reports in the published literature. The findings of this report contribute to the limited literature on LAM, highlighting the clinical variability of LAM and suggesting potential novel variants beyond the classic presentation, emphasising the importance of recognising diverse manifestations for accurate diagnosis and management. Early recognition of LAM is crucial for appropriate treatment and improved patient outcomes. Further research is needed to elucidate LAM's aetiology and underlying mechanisms to facilitate the development of more targeted therapeutic strategies.

FIGURE 1

A clinical images of the patient show linear hyperpigmented atrophic patches with an atypical Blaschkoid distribution (multiple band‐like pattern) on the right trunk (a and b), extending along Blaschko's lines to the right buttock and thigh (c).

FIGURE 2

H&E‐stained sections of the lesion. Panels (a–d) show normal epidermis with mild linear hyperpigmentation of the basal layer, altered collagen fibres, fragmentation of elastic fibres, spare perivascular lymphocytic infiltrate, and thinning of the subcutaneous layer (40×, 100×, 400×, 400×).

FIGURE 3

(a–d) Masson‐trichrome stain section revealed altered collagen fibers. (a) Shows a section of skin with the epidermis on the left side and the underlying dermis, indicating a clear boundary and altered collagen fiber arrangement in the dermal layer. (b) Displays disorganized and loosely arranged collagen fibers with a wavy pattern and varying thickness. (c) Highlights densely packed and thickened collagen fibers in a more organized manner, suggesting regions of increased collagen deposition. (d) Illustrates a section with both collagen fibers and adipose tissue, showing the interaction between the altered collagen matrix and fat cells.

FIGURE 4

Orcein stain section revealed fragmentation of elastic fibres.