Mycosis Fungoides as a Multifaceted Disease – A Case Report

Abstract Introduction: Mycosis fungoides (MF) is a primary cutaneous T-cell lymphoma with a highly variable clinical presentation, while histological findings are often typical. This case report presents an atypical, mimicking manifestation of MF in a 66-year-old patient, whose diagnosis required a multidisciplinary approach. Case presentation: The patient was hospitalized twice at the Department of Dermatology and venerology, University Hospital Centre Osijek, due to a persistent polymorphic rash of changing appearance, localized on the trunk, extremities, face, and the scalp. Considering the atypical clinical course, resistance to topical and systemic therapy, further diagnostic evaluation was required, including immunological, hematological, pulmonary, and infectious disease workup. Multidisciplinary collaboration ultimately led to the establishment of the MF diagnosis. Management and outcome: After failing to respond to topical and systemic corticosteroids, immunomodulators, antibiotics, and hydroxychloroquine, the patient showed a successful therapeutic response to oral methotrexate at a dose of 15 mg once weekly, resulting in complete resolution of skin lesions. Discussion: This clinical case serves as an example of an atypical clinical and histological presentation of MF, along with associated multiple pathological findings, which necessitated the exclusion of several other differential diagnoses. Conclusion: MF can mimic a wide spectrum of benign inflammatory dermatoses, both clinically and histopathologically. Confirming the diagnosis of MF, the so-called “great imitaror”, requires a multidisciplinary approach to both diagnosis and patient management. Keywords: epidermotropism; methotrexate; Mycosis fungoides