Asymptomatic Pulmonary Allograft Kaposi Sarcoma: A Case Report

Solid-organ transplant recipients are at high risk of developing malignancies. A greater risk of Kaposi sarcoma has been reported in lung recipients in our country, particularly in those from Southern Italy, probably due to the high prevalence of Human herpes virus 8 infection. Kaposi sarcoma affecting only the lung allograft is extremely rare. We describe a case of a lung recipient who developed Kaposi sarcoma only in the graft, 22 months after transplant. The patient, a 65-year-old man from Southern Italy, underwent bilateral lung transplant for idiopathic pulmonary fibrosis in January 2009. He developed mild/moderate acute cellular rejection (≥A2) in 4 of 6 scheduled transbronchial biopsies thus was treated with increased immunosuppressive therapy, shifting from cyclosporine to tacrolimus and mycophenolate mofetil. In July 2010, a high-resolution computed tomography scan showed small bilateral lung nodules, despite a generally good condition. After 2 months, his condition worsened with a severe weight loss. A positron emission tomography scan showed mild metabolic activity in the lesions with no other localizations. In October 2010, a lung biopsy was performed, with results showing typical histologic and immunohistochemical features of Kaposi sarcoma. Molecular tissue evaluations and serologic analyses were positive for Human herpes virus 8. The patient's immunosuppressive therapy was suspended, and he started liposomal doxorubicin treatment; however, after the first cycle, he developed severe respiratory dysfunction. The patient died 27 months after lung transplant for neoplasm. Our report highlights the importance of considering Kaposi sarcoma in the differential diagnosis for lung nodules in lung transplant recipients, even in the absence of any initial specific symptom or cutaneous lesion.