Folliculotropic mycosis fungoides with follicular mucinosis--case report.

Reports on clinical and histologic follicular alterations in patients previously diagnosed with mycosis fungoides (MF) or at the time of MF diagnosis are rare. The clinical and histologic criteria to distinguish MF associated with follicular mucinosis from follicular MF are a matter of debate. A patient is described with advanced clinical and histologic alterations predominated by follicular lesions and presence of mucin. In the early stage of the disease, folliculotropism was clinically and histologically present but less pronounced than epidermotropism and classic plaque-like lesions. The patient died four years after the diagnosis. As the term 'folliculotropic' describes a particular histopathologic finding, we consider it correct to use the term "folliculotropic MF" to denote atypical lymphocyte folliculotropism in the absence or presence of mild epidermotropism, presence of mucin, or no evidence for intrafollicular mucin. Folliculotropic MF seems to represent a specific clinicopathologic entity which may have a poorer prognosis than classic MF.