[Pilotropic T-cell lymphoma without mucinosis: 5 new cases]

Pilotropic cutaneous T-cell lymphomas without mucinosis are rare, with 27 cases previously reported. Diagnosis and classification may be difficult. The clinical course and histopathological and immunohistochemical findings in 5 patients are described.

Patients were selected from the register of the French Study Group for cutaneous lymphomas. The criteria for inclusion were clinical pilofollicular manifestations and histological features of pilotropic T-cell lymphoma without mucinosis.

Five patients were selected. The most frequent clinical manifestations were follicular keratosis, alopecia and follicular papules. Typical lesions of mycosis fongoides were present for several years in 3 patients, and lymphomatoid papulosis preexisted in one patient. Histopathological analysis showed an infiltrate composed of CD3+ and CD4+ atypical lymphocytes involving the follicular epithelium with alteration of the hair follicle walls. Epidermotropism was associated with pilotropism and situated near the follicular 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.

Diagnosis of pilotropic cutaneous T cell lymphomas without mucinosis may be difficult in case of discrete epidermotropism, minimal infiltrate or involvement of the follicular epithelium. Pilotropism could define a particular variant of T-cell lymphomas.