We read with interest the recent article by Cerroni and colleagues1 on the topic of follicular mucinosis (FM). We would like to emphasize several points made in the article as well as clarify others on the basis of our experience with this disorder.
First, we agree that there are no clinical criteria that can be strictly applied to distinguish cases of primary or "benign" FM from cases of mycosis fungoides (MF). However, generally in patients who have limited disease at the time of presentation, most often of the head and neck, the condition tends to have a benign course.2- 4 Although it is true that facial lesions can occur in MF-associated FM, we have described 7 patients who had multiple papular lesions of the head and neck that have not progressed to malignancy despite T-cell clonality in 5 of the patients (mean follow-up, 132 months).5 In our subset of patients, we have found no clinical or histologic evidence of MF. Solitary as well as multiple facial and neck lesions can demonstrate T-cell clonality but not progress to overt MF. Furthermore, we found a clonal infiltrate in 2 patients with widespread lesions that have not progressed to MF after 144 months of follow-up. Our conclusions otherwise have been similar to those of Cerroni and colleagues1 in that no clinical or histopathologic criteria seem to absolutely distinguish patients with primary FM from patients with MF-associated FM in the absence of well-defined histologic changes of MF. Furthermore, clonality in our experience to date does not necessarily lead to MF, nor does it preclude spontaneous regression or predict the duration of disease.
Gibson LE, Brown HA, Pittelkow MR, Pujol RM. Follicular Mucinosis. Arch Dermatol. 2002;138(12):1615. doi:10.1001/archderm.138.12.1613