Folliculotropic mycosis fungoides complicated by eosinophilia: a case report

Abstract

A 69-year-old man presented with a 3-year history of scattered erythematous patches, perifollicular papules, acneiform lesions (such as milia, cysts) on the head, trunk and limbs as well as alopecia and peripheral eosinophilia. Histopathological examination revealed chronic focal dermal and perifollicular inflammatory infiltration with vascular proliferation and presence of a small number of eosinophils. He was initially diagnosed with folliculitis, and treated with antihistamines and antibiotics. Thereafter, lesional inflammation and pruritus were attenuated. However, plaques and alopecia developed in the occipital area 3 months later. The second histopathology of biopsy specimens revealed a dense dermal infiltrate of lymphoid cells and eosinophils, perifollicular infiltrate with numerous lymphoid cells, eosinophils and atypical lymphocytes migrating into hair follicles. Alcian blue stain showed epidermal mucinosis in follicles. Immunohistochemical examination showed positive staining of atypical cells for CD3, CD4, CD5, CD2, CD43 and ubiquitin carboxyl-terminal esterase L1 (UCHL1), but negative staining for CD20, CD79a, Epstein-barr virus, CD56, phosphoglucomutase-1, myeloperoxidase, CD7, or AE1 and AE3 monoclonal anti-keratin antibodies. T-cell receptor gene rearrangement was undetected. He was diagnosed with folliculotropic mycosis fungoides. Novel skin lesions still emerged after treatment with photochemotherapy (PUVA) plus acitretin. Follow up of the patient still continued.