Reflectance confocal microscopy for the diagnosis of Langerhans cell histiocytosis

Dermoscopy and reflectance confocal microscopy finding of different anatomic sites of Langerhans cell histiocytosis

BACKGROUND

Recognizing Langerhans cell histiocytosis (LCH) might be a challenge due to its rarity. Reflectance confocal microscopy (RCM) and dermoscopy were emergent promising non-invasive technique as auxiliary tools in diagnosis of different skin conditions. However, the RCM and dermoscopic features of LCH had been less investigated. To reveal the common RCM and dermoscopic features of LCH.

MATERIALS AND METHODS

Forty cases of LCH were retrospectively analyzed according to age, locations, clinical, RCM, and dermoscopic features from September 2016 to December 2022. To reveal the differences and common in clinical, RCM, and dermoscopic features that occur in different anatomic location.

RESULTS

In the study, sites of predilection include the trunk 31/40 (77.5%), extremity 21/40 (52.5%), face 14/40 (35%), scalp 11/40 (27.5%), vulvar 4/40 (10%), and nail 2/40 (5%). All LCHs had the common RCM features. There were significant differences in clinical and dermoscopic features for age and lesion anatomic site. The common dermoscopic features for scalp, face, trunk, and extremity were the erythematous scaly rash, purplish-red globules or patches, scar-like streaks with ectatic vessels. While the features for nail LCH were purpuric striae, onycholysis and purulent scaly rash, and the erosive erythematous plaque and purulent scaly rash for vulvar LCH. The common RCM features of all LCH showed a focal highly reflective dense image in the surface keratin layer, epidermis architectural disarray, obscuration of dermo-epidermal junction, numerous polygonal, large, medium reflective, short dendrites cells in the epidermis, and dermis. All LCH involving the vulvar and nail did not manifest skin lesions.

CONCLUSION

RCM and dermoscopy showed promising value for diagnosis and differentiation of LCH.

Dermoscopy combined with reflectance confocal microscopy as a noninvasive involvement for monitoring Cutaneous Rosai-Dorfman: A case report

Cutaneous Rosai-Dorfman disease(CRDD) is an extremely rare entity and features histiocytic proliferation in the skin. Dermoscopy and reflectance confocal microscopy(RCM) reports on CRDD are rare. We reported a case of CRDD and summarized the dermoscopy(FotoFinder Medicare 800HD, FotoFinder-Systems GmbH, Birbach Germany) and RCM(VivaScope® 1500, V Caliber Imaging and Diagnostics) features of CRDD. The dermoscopic features of CRDD showed red-orange background with pale yellowish roundish areas similar to millet, surrounded by branched blood vessels. Sometimes the white structureless materials of CRDD could be observed by dermoscopy, which may be a hint of spontaneous regression. The RCM features of CRDD revealed dense highly refractile roundish or ovoid structures(inflammatory cells), and multiple larger structures with central low refraction and moderately refractive peripheral semicircle or circle(engulfed inflammatory cells), together with low refractive branched structures(blood vessels). Dermoscopic and RCM features of CRDD can help the dermatologists recognize and follow-up the disease in real time.