Low-dose corticosteroid induced Kaposi sarcoma in psoriatic arthritis: A case report [Su di un caso di artrite psoriasica in trattamento con cortisonici a basse dosi associato a Sarcoma di Kaposi]

A case of Kaposi's sarcoma complicating a psoriatic arthritis, in a HIV- negative patient, treated with low-dose corticosteroid is described. It is known that immunosopressive treatment may trigger this neoplasm. Methotrexate, cyclophosphamide, azathioprine, radiotherapy, photochemiotherapy are able to induce immunologic disturbances and patients under immunosopressive treatment run an increased risk of developing malignant tumors such as Kaposi's sarcoma. Although diseases that require steroid treatment are very common, the appearance of this complication is very rare and the risk is not strictly dose-related. It is our opinion that other factors such as genetic or viral infection could be involved as co- factors in the development of the neoplasm leading to a breakdown in immunologic surveillance. We also demonstrated a highly expressed bcl-2 related-protein on perivascular inflammatory cells. We believe that this feature could be of some importance in the demonstration of a systemic immunologic abnormality leading to a cellular proliferation depending upon an altered apoptotic process.