Pilotropic cutaneous T cell lymphomas without mucinosis: five new cases

Background. Pilotropic cutaneous T-cell lymphomas without mucinosis are rar e, with 27 cases previously reported. Diagnosis and classification may be d ifficult. The clinical course and histopathological and immunohistochemical findings in 5 patients are described. Patients and methods. Patients were selected from the register pf the Frenc h Study Group for cutaneous lymphomas. The criteria for inclusion were clin ical pilofollicular manifestations and histological features of pilotropic T-cell lymphoma without mucinosis. Results. Five patients were selected. The most frequent clinical manifestat ions were follicular keratosis, alopecia and follicular papules. Typical le sions of mycosis fongoides were present for several years in 3 patients, an d lymphomatoid papulosis preexisted in one patient. Histopathological analy sis showed an infiltrate composed of CD3+ and CD4+ atypical lymphocytes inv olving the follicular epithelium with alteration of the hair follicle walls . Epidermotropism was associated with pilotropism and situated near the fol licular lesions or farther apart. Alcian blue stains results were negative in all specimens. PCR studies showed the presence of a T-cell clone in the skin lesions in all cases. Comments. Diagnosis of pilotropic cutaneous T cell lymphomas without mucino sis may be difficult in case of discrete epidermotropism, minimal infiltrat e or involvement of the follicular epithelium. Pilotropism could define a p articular variant of T-cell lymphomas.