Dermoscopy: an easy, noninvasive tool for distinguishing mycosis fungoides from other inflammatory mimics

Background Mycosis fungoides (MF), the most common type of cutaneous T-cell lymphoma, can sometimes be indistinguishable from plaque psoriasis (PP), chronic dermatitis, and lichen planus (LP). Objective The aim of the study was to assess the value of dermoscopy as a quick screening tool to distinguish MF from PP, chronic dermatitis, and LP. Patients and methods The dermoscopic profiles of 21 MF, 20 PP, 20 chronic dermatitis, and 20 LP patients were included in this study. Results All 20 PP patients (100%) showed homogenous red globules on a red background with white scales. All 20 LP patients (100%) showed whitish projections. In chronic dermatitis, all 20 (100%) patients showed patchy red dots and globules with yellowish scales. All MF patients showed pinkish homogeneous backgrounds. Whitish scales were seen in 15/21 (71.4%) MF patients. In recent-onset MF (disease duration ≤2months), fine short linear vessels were seen in 4/21 (19%) patients and spermatozoa-like vessels in 3/21 (14.2%) patients. These features were statistically significant when compared with all the 81 examined patients (P =0.0036 and 0.0156, respectively). In contrast, in hyperpigmented MF lesions, dark globules were seen in 10/21 (47.6%) and light brown multifocal pigmentation was seen in 10/21 (47.6%) patients. These features were statistically significant when compared with all the 81 examined patients (P 0.0001). Conclusion Fine short linear vessels, spermatozoa-like vessels, dark globules, and light brown multifocal pigmentation on a pink homogenous background are highly suggestive of MF. Dermoscopy proved to be a useful tool in distinguishing between MF, PP, chronic dermatitis, and LP.