Two Cases of Mycosis Fungoides Diagnosed during Dupilumab Treatment / 대한피부과학회지

Dupilumab, a human monoclonal antibody targeting the interleukin-4 receptor α, has exhibited rapid and remarkable therapeutic efficacy in numerous clinical trials focusing on moderate-to-severe atopic dermatitis and prurigo nodularis. Nonetheless, instances of mycosis fungoides have been reported in patients undergoing dupilumab treatment for atopic dermatitis. We present two cases: a 36-year-old woman and a 64-year-old man who presented to our dermatology clinic with erythematous papules and plaques. Following skin biopsy, both patients were diagnosed with chronic eczematous dermatitis with prurigo. Erythematous plaques notably increased after 9 months and 1 month of dupilumab treatment, respectively. Subsequent biopsies confirmed histopathological markers consistent with mycosis fungoides. The first patient underwent chemotherapy for lymph node metastasis, while the second received oral acitretin, narrow-band ultraviolet B, and topical corticosteroids.

A Novel Mutation in the MBTPS2 Gene Resulting in Ichthyosis Follicularis, Atrichia, and Photophobia Syndrome

Ichthyosis follicularis, atrichia, and photophobia (IFAP) syndrome is a rare genetic disorder caused by mutations in the MBTPS2 gene. It is characterized by ichthyosis and alopecia from birth. Photophobia may be present in infancy or early childhood. Its mode of inheritance is X-linked recessive; thus, it mostly affects male. The disease severity varies, ranging from mild cases limited to the skin to the severe variant involving multiple extracutaneous features. A 7-year-old boy presented with scanty hair on scalp and eyebrows at birth. On physical examination, scaly patches were observed on the whole body and spiky follicular hyperkeratotic papules were observed on the face and trunk. He also suffered from severe photophobia. Histopathological examination of the scalp showed miniaturized hair follicles without perifollicular fibrosis. Genetic analysis revealed a novel mutation in the MBTPS2 gene which was a homozygous missense mutation of c.245T>C leading to an amino-acid substitution from phenylalanine to serine (p.Phe82Ser). We diagnosed this patient with IFAP syndrome. To date, 25 pathogenic MBTPS2 gene mutations have been identified. To our knowledge, c.245T>C is a novel homozygous missense mutation in the MBTPS2 gene, which has not been reported in Human Gene Mutation Database, ClinVar Database, and Leiden Open Variation Database. Previous reports suggested genotype-phenotype correlations in the MBTPS2 gene mutations. Supported by a previous notion that genotype correlates with phenotype, this novel mutation can be a predictive factor for the mild form of IFAP syndrome, restricted to the classic symptom triad.

CD30＋ Large-Cell Transformation of Mycosis Fungoides Treated with Brentuximab Vedotin / 대한피부과학회지

Large-cell transformation of mycosis fungoides (LCT-MF) is an advanced stage of primary cutaneous T-cell lymphoma with a poor prognosis. Therapeutic options for these patients are often limited, and so far, they are not promising. An 81-year-old woman with a previous history of mycosis fungoides presented with aggravation of generalized erythematous scaly patches and new onset of ulcerated tumor on the abdomen for 3 months.Histopathological examination revealed a dense dermal infiltrate composed of atypical large lymphocytes. Immunohistochemically, the tumor cells were positive for CD30 expression. A diagnosis of CD30＋ LCT-MF was established. She was intensively treated with methotrexate (1 month), acitretin (1 month), and rituximab with dose-modified cyclophosphamide, doxorubicin, and prednisone (1 cycle). Despite such treatments, the improvement was minimal. Subsequently, the patient was started on brentuximab vedotin, 1.8 mg/kg intravenously once every 3weeks. She responded well to brentuximab therapy, and the skin lesions completely subsided within 12 weeks of treatment.