Pediatric follicular mucinosis: presentation, histopathology, molecular genetics, treatment, and outcomes over an 11-year period at the Mayo Clinic.

Follicular mucinosis (FM) and folliculotropic mycosis fungoides (MF) are rare in children, and data regarding long-term outcomes are limited. We sought to describe clinical and histopathologic findings of children with FM with and without MF, as well as treatments administered and clinical outcomes. We conducted a retrospective chart review of patients younger than 22 years (at time of diagnosis) with a biopsy demonstrating FM who were seen in the Dermatology Department at the Mayo Clinic from September 1, 1999, to September 1, 2010. Eleven patients (six male, five female) ages 11 to 19 years at the time of diagnosis met the inclusion criteria. Follow-up data were available for 10 patients, with a mean duration of 4.9 years. The head, neck, and extremities were the most common sites of involvement, and lesions were follicular-based papules (18%), scaly alopecic patches and plaques (45%), or a combination of the two (36%). Overall, three patients were confirmed to have MF. T-cell receptor gene rearrangement demonstrated clonality in two cases and was equivocal in one case. Treatments included topical corticosteroids, topical retinoids, oral minocycline, and, in patients with MF, ultraviolet light and topical bexarotene. Lesions resolved completely in seven patients, partially in one, and not at all in two (no follow-up data on one patient). Of the three patients with MF, two had complete resolution, and one has intermittent flares. To our knowledge, no patients developed other lymphoproliferative disorders. FM in children is rare. A histopathologic diagnosis of FM does not equate to folliculotropic MF in all cases. Most patients responded to treatment with topical steroids, topical retinoids, or phototherapy. In our series of patients, the disease ran a benign course.

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.

Mycosis fungoides with follicular mucinosis displaying aggressive tumor-stage transformation : successful treatment using radiation therapy plus oral bexarotene combination therapy.

Follicular mucinosis is a tissue reaction pattern characterized by mucin deposition with follicular sebaceous units and is found as an idiopathic, primary, benign process (alopecia mucinosa), or as a secondary process due to inflammatory and neoplastic disorders (mycosis fungoides). When associated with follicular mucinosis, mycosis fungoides commonly pursues an aggressive course, often undergoing large-cell transformation, which is associated with resistance to therapy and poor prognosis. We present a case of mycosis fungoides with follicular mucinosis that was treated with incomplete courses of interferon, isotretinoin, and polychemotherapy with subsequent rapid progression to tumor-stage mycosis fungoides with large cell transformation and nodal and bone marrow involvement. In this setting, the patient was treated with local radiation therapy, total-skin electron beam therapy, and therapy and maintenance with the oral retinoid-X-receptor retinoid bexarotene, and achieved a durable complete remission.