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.

Treatment of so-called idiopathic follicular mucinosis with hydroxychloroquine.

There exists no treatment of choice for follicular mucinosis (FM). Historically two distinct entities of FM have been proposed: FM of children and young adults not associated with other diseases ('idiopathic' FM), and FM in elderly patients associated with mycosis fungoides and Sézary syndrome ('lymphoma-associated' FM). Nowadays it is suggested that 'idiopathic' FM might represent a localized form of cutaneous T-cell lymphoma. Six patients with 'idiopathic' FM were treated with hydroxychloroquine (HCQ) at a dose of 200 mg three times daily for 10 days followed by a dose adjusted to the ideal body weight, usually 200 mg twice daily. All patients showed an improvement of 'idiopathic' FM already after 6 weeks and a complete remission with full hair regrowth after 2-5 months of HCQ therapy. In all patients no relapse occurred during follow up of between 3 and 23 years and no patient developed lymphoma. We conclude that HCQ is a highly effective therapy without significant side-effects in the treatment of so-called 'idiopathic' FM.

Follicular mucinosis: a clinicopathologic, histochemical, immunohistochemical and molecular study comparing the primary benign form and the mycosis fungoides-associated follicular mucinosis.

OBJECTIVES: To determine (i) whether primary (idiopathic) follicular mucinosis (PFM) and lymphoma-associated follicular mucinosis (LAFM) are distinct or related entities and whether there are reliable criteria that allow the two forms to be distinguished, (ii) the histochemical properties and consequently the type of mucin that accumulates in the follicle in PFM and LAFM, and (iii) whether there is any difference between the staining properties of mucin in patients with PFM and LAFM. METHODS: Thirty-one patients were divided into two groups. Group 1 comprised 20 patients with no associated mycosis fungoides or Sézary syndrome (PFM) and group 2 was made up of the other 11 patients who had clinicopathological evidence of cutaneous T-cell lymphoma (LAFM). The biopsy specimens of the patients were studied with histopathological, histochemical and immunohistochemical methods. Molecular biology studies were also performed. RESULTS: Patients with PFM were more frequently younger (mean age 39 years), women (F:M=3:1), and presented with a solitary lesion involving the head/neck area more often than patients with LAFM who were older (mean age 54 years), men (M:F=2:1), and presented with multiple lesions on areas of the body other than the head/neck area. As for histopathological findings, large cystic spaces filled with mucin and a slight perivascular and periadnexal polyclonal infiltrate of mostly non-atypical lymphocytes without epidermotropism and with an equivalent CD4+/CD8+ cell rate were more suggestive of PFM. On the contrary, patients with LAFM were more probably to present with a dense band-like infiltrate with some atypical lymphocytes and sign of epidermotropism, a prominent CD4+ immunophenotype and a monoclonal rearrangement of the infiltrate. Mucin proved to be a dermal-type mucin, composed of both hyaluronic acid and sulfated glycosaminoglycans. No differences were found in the composition of the follicular mucin in the PFM compared with LAFM. CONCLUSIONS: Although no single, indisputable feature can reliably differentiate PFM from LAFM and a considerable overlapping among the two groups exists, the use of multiple clinical, histological and immunopathological criteria associated with gene rearrangement analysis can be useful in evaluation of those patients.

Folliculotropic mycosis fungoides (stage IIA) progressing to Sézary syndrome: a case report.

Folliculotropic mycosis fungoides is associated with a worse prognosis than classical mycosis fungoides (MF), but whether this is due to resistance to skin-directed therapy or to biological differences is unclear. We discuss a case of a patient with folliculotropic MF (stage IIA) who progressed to develop Sézary syndrome (SS), stage IVB, over 6 years. A 40-year-old man presented with pruritic plaques affecting his head and trunk, characterized by follicular plugging. The histology was consistent with folliculotropic MF and T-cell gene analysis studies revealed a T-cell clone in the skin only. His condition gradually deteriorated and 5 years after presentation, T-cell gene analysis studies revealed the presence of a clone in the blood identical with that seen in the skin. His condition progressed with the development of erythrodermic disease and a leukaemic blood picture and he subsequently died of systemic nodal and visceral involvement. We present the first report detailing the stepwise progression of a patient with stage IIA folliculotropic MF to SS. This case demonstrates that MF and SS represent a clinical spectrum of the same disease.

Follicular mycosis fungoides: a histopathologic, immunohistochemical, and genotypic review.

Follicular mycosis fungoides (FMF) is a recognized variant of mycosis fungoides. In this review, the authors characterize the distinct histopathological and immunohistochemical patterns of FMF that have been reported in the literature. This article is an extensive review of the literature cited in Medline and own data of the authors. The major patterns of FMF histopathology, immunohistochemistry, and molecular genetics are summarized in this review. Histologically, the quintessential finding in FMF is small to medium atypical CD3+ CD4+ CD8- T lymphocytes around and within the epithelium of the hair follicles. This finding is requisite to the diagnosis. However, this finding may be obscured by a host of other patterns often identified in FMF. This includes basaloid folliculo-lymphoid hyperplasia, a granulomatous reaction, eosinophilic folliculitis, and follicular cystic changes with subtle atypical lymphocytes in the cyst wall. Follicular mucinosis (MF) and syringo-tropism are also variably present. Immunohistochemistry of all reported cases uniformly show a CD4+ T cell infiltrate. This review emphasizes and discusses the broad spectrum of histologic changes which may be seen in FMF, clues to the diagnosis, and some potential mimickers.

Failure to detect clonality in eosinophilic pustular folliculitis with follicular mucinosis.

Eosinophilic pustular folliculitis is characterized by an eosinophil-rich inflammatory follicular and perifollicular infiltrate primarily centred at the level of the follicular isthmus and sebaceous duct. Follicular mucinosis has been observed in lesions of eosinophilic pustular folliculitis. Clinical and histological features of eosinophilic pustular folliculitis with follicular mucinosis and alopecia mucinosa are very similar. Alopecia mucinosa may be a clonal T-cell dermatosis. A monoclonal re-arrangement of the T-cell receptor gene was detected in about half of the cases in alopecia mucinosa. To investigate T-cell clonality in a series of eosinophilic pustular folliculitis with follicular mucinosis, we performed heteroduplex analysis of re-arranged T-cell receptor gamma gene in seven cases of eosinophilic pustular folliculitis with follicular mucinosis. All cases were negative for heteroduplex-PCR analysis. The failure to demonstrate clonality may be consistent with a reactive nature of eosinophilic pustular folliculitis with follicular mucinosis.

Primary follicular mucinosis: long-term follow-up of patients younger than 40 years with and without clonal T-cell receptor gene rearrangement.

Since the original descriptions of follicular mucinosis, accumulating experience shows that patient age, distribution of lesions, and duration or extent of disease do not reliably distinguish benign primary follicular mucinosis from secondary follicular mucinosis, associated with cutaneous lymphoma. More recently, it has been suggested that individuals with follicular mucinosis demonstrating a clonal T-cell receptor gene rearrangement may be at higher risk for the development of lymphoma. Long-term follow-up of 7 patients younger than 40 years with primary follicular mucinosis are reported. In all cases, there was no clinical or histologic evidence of associated dermatoses or lymphoma at the time of diagnosis. Five of the patients have clonal T-cell gene rearrangement as determined by Southern blot analysis. Clinically, at the time of diagnosis, lesions of primary follicular mucinosis ranged from papules confined to the face to widespread cutaneous plaques. After a mean follow-up of 10 years (range, 5-23 years) from the onset of disease, the majority of patients continue to have cutaneous manifestations of follicular mucinosis despite various treatments. There is no evidence of progression to cutaneous T-cell lymphoma in any patient despite the presence of a clonal T-cell receptor gene rearrangement. Continued prolonged follow-up of patients with clonal primary follicular mucinosis is necessary to determine the significance of infiltrates harboring a T-cell receptor gene rearrangement. However, in our experience with this group of selected patients, primary follicular mucinosis has been a clonal disorder with limited or "benign" cutaneous manifestations.

A case of follicular mycosis fungoides with follicular mucinosis: a rare association.

Follicular mycosis fungoides (FMF) is a rare cutaneous T cell lymphoma characterized by an atypical lymphoid infiltrate spreading within and around hair follicles without epidermotropism or follicular mucin deposits. Its occasional presentation with minimal epidermal involvement and/or follicular mucinosis suggests the need for uniform histologic criteria. We describe a new case of FMF associated with follicular mucinosis and discuss its morphologic spectrum of presentation.

Follicular mucinosis: a critical reappraisal of clinicopathologic features and association with mycosis fungoides and Sézary syndrome.

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.

Mucinosis folicular: nuevas entidades clínico-patológicas. Estudio clínico, histológico, inmunohistoquímico e inmunogenotípico de 23 pacientes* / Follicular mucinosis: new clinicopathologic entities. Clinical, histological, immunohistochemical and immunogenotypic study of 23 patients

En el presente trabajo se realiza una revisión clínica, histológica, inmunohistoquímica e inmunogenotípica de 23 pacientes con mucinosis folicular. Se incluyeron en el trabajo pacientes con mucinosis folicular primaria (MFP) y pacientes con mucinosis folicular secundaria (MFS) a linfoma sistémico o linfoma cutáneo de células T. Se seleccionaron del archivo de histopatología las biopsias con diagnóstico de mucinosis folicular desde 1975 al año 2000 con el único criterio de mostrar degeneración mucinosa en el epitelio folicular con un infiltrado inflamatorio acompañante. En todas las biopsias se efectuaron tinciones inmunohistoquímicas con marcadores pan B, pan T, T4 y T8. En casos seleccionados se realizó detección de reordenamiento clonal del receptor T mediante PCR de cortes en parafina de las biopsias. Se encontraron seis casos de MFS (30,4% del total), todos ellos varones de una edad media de 50,4 años. El linfoma más frecuentemente asociado fue la micosis fungoide. Dieciséis casos correspondían a MFP (ocho varones y ocho mujeres; edades entre 8 y 72 años). En este grupo de pacientes se identificaron cuatro formas clínicas de presentación: MFP localizada, MFP difusa, MFP acneiforme y MFP urticarial. No existieron diferencias histológicas sustanciales entre la MFS y la MFP. Tan sólo la forma urticarial de la mucinosis folicular presentaba características histológicas diferenciales, como fueron un abundante infiltrado inflamatorio y abundantes eosinófilos. Los hallazgos inmunohistoquímicos confirman que el infiltrado inflamatorio está formado preferentemente por linfocitos T helper. Los estudios de reordenamiento demostraron tres casos de MFP con clonalidad, sin que se pudieran encontrar características diferenciales entre éstos y las formas no clonales. Pese a la clonalidad ninguno de estos tres casos evolucionó posteriormente a linfoma, lo que sostiene la teoría de las dermatosis benignas clonales, recientemente propuesta. No obstante, parece aconsejable un seguimiento prolongado de los casos de mucinosis folicular primaria con clonalidad en el estudio genético (AU)

Follicular mucinosis presenting as an acneiform eruption: report of four cases.

Follicular mucinosis can be a primary idiopathic disease or a secondary disease associated with lymphoma. When it appears in childhood or adolescence, it is usually primary and self-limited. We describe four cases of follicular mucinosis occurring in early adulthood that have had protracted courses. Each presented as an unusual acneiform eruption. Two of the cases demonstrated a clonal genetic rearrangement of the T-cell receptor within the cutaneous lymphoid infiltrate, a finding not previously reported. Although its significance is not clear, the clonal lymphocytic expansion indicates a need for continued surveillance of these patients.

T-cell receptor gene rearrangement analysis: cutaneous T cell lymphoma, peripheral T cell lymphoma, and premalignant and benign cutaneous lymphoproliferative disorders.

T-cell receptor gene rearrangement analysis is a useful technique to detect clonality and determine lineage of lymphoid neoplasms. We examined 103 patients with mycosis fungoides, Sézary syndrome, peripheral T cell lymphoma, potentially malignant lymphoproliferative disorders including pre-Sézary syndrome, large plaque parapsoriasis, lymphomatoid papulosis and follicular mucinosis, and various benign inflammatory infiltrates. A clonal rearrangement was detected in skin samples in 20 of 24 patients with mycosis fungoides and in peripheral blood samples in 19 of 21 patients with Sézary syndrome. A clonal population was also detected in seven of eight cases classified as peripheral T cell lymphoma. The potentially malignant dermatoses tended to have clonal rearrangement, with the exception of large plaque parapsoriasis, and further follow-up is needed to correlate clonality with the disease course. These studies demonstrate the value of molecular genetics as an adjunct to morphology in the examination of patients with cutaneous lymphoproliferative disease.

Follicular mucinosis: histopathologic review of 33 cases.

Among 33 patients with the histologic diagnosis of follicular mucinosis (alopecia mucinosa) made at our institution between 1982 and 1989, 9 had mycosis fungoides diagnosed concomitantly. Three other patients had lymphoproliferative disorders, and two had Kaposi's sarcoma. Analysis of biopsy features such as epidermal lymphocytic exocytosis, periappendageal infiltrate, and deposition of mucin revealed no predominant finding that distinguished a benign course from mycosis fungoides. A predominance of eosinophils in the infiltrate was suggestive of benign follicular mucinosis rather than mycosis fungoides. Gene rearrangement studies detected three clones in three patients with follicular mucinosis; two were in patients with mycosis fungoides, and one was in a patient with dermatitis. The outcome of these three patients is pending further follow-up. No histopathologic or clinical features distinguished these patients from the others.

Clonal rearrangement of the T cell receptor beta gene in the circulating lymphocytes of erythrodermic follicular mucinosis.

Follicular mucinosis is a condition characterized by the abnormal accumulation of acidic mucopolysaccharides in hair follicles. It is classically described as occurring idiopathically in young persons and within the infiltrates of mycosis fungoides in older individuals. We report a 12-year-old girl who had erythrodermic follicular mucinosis, hypereosinophilia, circulating Sezary cells, and both immunophenotypic and genotypic evidence of T cell neoplasia. Erythrodermic follicular mucinosis may represent an unusual variant of the Sezary syndrome, which to date has not been described in children or adolescents.