An update on long-term outcomes of pediatric follicular mucinosis over a 20-year period: a retrospective cohort study.

BACKGROUND: Follicular mucinosis (FM) is a rare disease characterized by mucin accumulation in the follicular unit. FM's etiology is still widely debated since its first description in 1957. Follicular mucinosis is usually reported to be benign in children, although reports of malignant transformation, most commonly mycosis fungoides, exist. The present project aims to demonstrate that children with a diagnosis of follicular mucinosis have positive long-term outcomes and do not develop mycosis fungoides. MATERIALS AND METHODS: This is a retrospective cohort study where patients with a diagnosis of follicular mucinosis ages 22 years and below were identified. Data surrounding the patient's diagnosis of FM, differential diagnosis, treatments, and long-term outcomes were collected. Patients who were lost to follow-up were contacted by phone for an update on the status of their skin and overall health. RESULTS: Out of 14 patients with follow-up information, none developed subsequent mycosis fungoides or other hematologic malignancies. CONCLUSION: Pediatric patients with follicular mucinosis will likely present with limited disease and not experience malignant transformation.

Follicular mucinosis successfully treated by photodynamic therapy: Two case reports.

Follicular mucinosis is an epithelial reaction pattern characterized by follicular mucin accumulation. Follicular mucinosis may occur in a primary form or a secondary form associated with skin lymphoma, especially mycosis fungoides. This report describes two patients with these two forms of follicular mucinosis, who both had an excellent response to photodynamic therapy. The condition changes of the secondary follicular mucinosis patient were followed up by repeated pathological biopsies. The expression of CD103, a specific marker of tissue-resident memory T cells, was found to decline when the lesions improved. These results indicate an association between efficacy and pathological changes during the treatment of secondary follicular mucinosis.

Follicular mucinosis with novel dermoscopic finding: the toothpaste sign.

We describe a case of follicular mucinosis presenting with patchy alopecia affecting the eyebrows. On dermoscopy, white gelatinous material (presumed to be mucin) was visible along the hair shafts of the eyebrow lesions. We propose to call this novel dermoscopic finding the 'toothpaste sign'.

Basaloid follicular hamartoma associated with follicular mucinosis and inflammation.

Basaloid follicular hamartoma is a benign, superficial malformation of hair follicles that can be mistaken both clinical and histopathologically for basal cell carcinoma. Basaloid follicular hamartoma has been linked to a mutation in the PTCH-1 gene, which is part of the same pathway involved in Gorlin-Goltz syndrome. Here we present a 9-year-old patient with an asymptomatic congenital lesion on the forehead, which increased in size over the years. Histopathology showed a basaloid follicular hamartoma associated with follicular mucinosis and inflammation. Gorlin-Goltz syndrome was ruled out by clinical examination.

Eosinophilic folliculitis, eosinophilic dermatosis of hematologic malignancy and acneiform follicular mucinosis: Two case reports and a review of the literature highlighting the spectrum of histopathology.

Within the literature, there is overlap in the histopathological features described in eosinophilic folliculitis associated with chronic lymphocytic leukemia (CLL), eosinophilic dermatosis of hematologic malignancy, and acneiform follicular mucinosis. These disorders are described with varying degrees of superficial and deep lymphocytic and eosinophilic inflammation demonstrating perivascular, perifollicular, and folliculocentric involvement with or without follicular mucin deposition. Given significant histopathological overlap, these diagnoses may represent a continuum on a spectrum of dermatoses. Here, we present two cases with histopathological elements that reflect components of this clinicopathological spectrum and compare our findings with previously reported cases to compare and contrast reported features. Our first case is a 71-year-old African American man with long-standing CLL who developed a pruritic erythematous papular eruption on the face and chest with biopsy revealing a dense folliculotropic lymphocytic infiltrate with conspicuous eosinophils and follicular mucinosis. Our second case is a 70-year-old Caucasian man recently diagnosed with CLL/small lymphocytic lymphoma who developed an erythematous papular rash on the neck and face with biopsy revealing superficial and deep perivascular and periadnexal lymphocytic inflammation with scattered eosinophils. Characterization of our two cases and comparison with available literature suggest that these disorders may represent a continuum of dermatoses.

Follicular mucinosis: a review.

Follicular mucinosis (FM) is an epithelial reaction pattern characterized by follicular mucin accumulation. It has been described in association with various inflammatory and neoplastic cutaneous disorders. FM is generally divided into a primary benign idiopathic form and a secondary form usually occurring in association with cutaneous lymphomas (especially mycosis fungoides), among other entities. Distinction between the two forms can be challenging as they share many overlapping features and the lack of a single diagnostic tool to differentiate between the two. Making the distinction may require evaluating and correlating the clinical, histologic, immunohistochemical, and molecular studies together. Long-term clinical follow-up also remains very important. In this review, we describe the different entities associated with FM, its pathogenesis, and possible therapeutic options.