Granulomatous Mycosis Fungoides Associated with Knee Prostheses: A Case Report and Literature Review

Background: Granulomatous Mycosis Fungoides (MF) is a rare subtype of cutaneous T-cell lymphoma characterized by granulomatous inflammation. While MF is relatively well-known in dermatological practice, its association with prosthetic implants, particularly knee prostheses, is exceedingly rare. This case presents a novel instance of granulomatous MF potentially triggered by the chronic inflammation associated with a metallic knee prosthesis. Case description: We report the case of an 87-year-old female patient with ischemic heart disease and a total knee prosthesis, who presented with erythematous arcuate rash and nodules confined to the area around her right knee. Histopathological findings revealed non-necrotizing granulomas with epidermotropism, and immunohistochemistry confirmed the presence of CD4+/CD8+ T-cell infiltration, consistent with a diagnosis of granulomatous MF. The association between her prosthetic knee and the development of this condition is discussed. Conclusion: This case represents one of the first documented instances of granulomatous MF potentially linked to knee prosthesis. It highlights the need for vigilance in monitoring patients with prosthetic implants for rare, chronic inflammatory responses that may lead to lymphoproliferative disorders.