To assess the reflectance confocal microscopic (RCM) features of hypopigmented mycosis fungoides (HMF) .

A total of 8 patients with histopathologically and immunohistochemically diagnosed HMF were enrolled in this study. RCM imaging and histopathological study were both performed to examine lesions at the same site in these patients. A comparison was conducted between confocal microscopic and pathological findings.

RCM imaging in the 8 cases showed mild hyperkeratosis, and single or clustered, moderately reflective, oval or quasi-circular, polymorphic mononuclear cells with mildly reflective perinuclear halos in the epidermis. The reflectivity of pigmented rings in the basal layer was weakened. Many irregularly sized polymorphic mononuclear cells infiltrated the dermal papilla. Moderately reflective, circular or quasi-circular mononuclear cells gathered to form vesicle-like structures in some areas of the epidermis. RCM images were highly consistent with histopathological findings in these patients.

RCM may be used as a non-invasive imageological technique in the auxiliary or differential diagnosis of HMF.

Microscopy, confocal; Hypopigmentation; athology; Immunohistochemistry; Mycosis fungoides