Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma and is usually characterized by a T-helper phenotype of neoplastic cells. Several clinical, histopathologic, and phenotypic variants of the disease have been described. We report on a case of MF in tumor stage with neoplastic cells expressing a T-follicular helper phenotype, characterized by positivity for PD-1, Bcl-6, and CXCL-13. Retrospective analysis of the first diagnostic biopsy of patch stage MF revealed a similar phenotype. This review addresses the clinical, histopathologic, phenotypic, differential diagnostic, and prognostic features of typical and of less conventional cases of MF.