CONTEXT: Beginning in 1957, patients have been described with localized alopecia characterized histopathologically by mucin deposition within hair follicles (follicular mucinosis [FM]). At least 2 distinct diagnostic entities have been proposed: one occurring in children and young adults without association with other diseases ("idiopathic" FM), the other occurring in elderly patients and associated with mycosis fungoides or Sézary syndrome ("lymphoma-associated" FM).
OBJECTIVE: To determine whether idiopathic and lymphoma-associated FM are distinct or related entities.
DESIGN: Case series.
SETTING: Department of Dermatology, University of Graz, Graz, Austria.
PATIENTS: Forty-four patients with FM were divided into 2 groups. Group 1 comprised 16 patients (mean age, 37.5 years) with no associated mycosis fungoides or Sézary syndrome; group 2 was made up of the other 28 (mean age, 52.2 years), who had clinicopathologic evidence of cutaneous T-cell lymphoma.
RESULTS: Mean age was lower in patients with idiopathic FM, but a considerable overlapping among the 2 groups was present. Location on the head and neck region was common in both groups, but most patients with lymphoma-associated FM had lesions also on other body sites. In fact, solitary lesions at presentation were common in patients with idiopathic FM (11 [68.8%] of 16 patients), but uncommon in those with lymphoma-associated FM (2 [7.1%] of 28 patients). Histopathologic findings did not allow clear-cut differentiation of the 2 groups. Finally, a monoclonal rearrangement of the T-cell receptor gamma gene was demonstrated by polymerase chain reaction analysis in about 50% of tested cases from each group.
CONCLUSIONS: Criteria previously reported to differentiate idiopathic from lymphoma-associated FM proved ineffective. In analogy to localized pagetoid reticulosis (Woringer-Kolopp disease), small-plaque parapsoriasis, and so-called solitary mycosis fungoides, idiopathic FM may represent a form of localized cutaneous T-cell lymphoma.
Follicular mucinosis can occur as a primary idiopathic disorder or can arise in association with benign or malignant disease, most notably mycosis fungoides. We describe a patient with an aggressive folliculotropic variant of mycosis fungoides that initially presented as follicular mucinosis with alopecia. One month after the diagnosis of follicular mucinosis, a diagnosis of mycosis fungoides was made, and 3 months later inguinal lymph node involvement with mycosis fungoides developed. A skin biopsy specimen demonstrated prominent follicular mucinosis with folliculotropism of atypical cells and intrafollicular Pautrier's microabscesses. As demonstrated in this case, follicular mucinosis can be a presenting sign of rapidly progressive mycosis fungoides. In our review of follicular mucinosis and its association with mycosis fungoides, we found that the folliculotropic variant of mycosis fungoides appears more commonly to have an aggressive course than classic mycosis fungoides.