Bone involvement in classic Kaposi’s sarcoma

Background: Classic Kaposi’s sarcoma (KS) is arare angioproliferative neoplasm which typically occurs on the skin of the lower limbs of immunocompetent elderly men. Bone involvement in classic KS has been exceptionally reported. Objectives: To identify patients with classic KS who developed bone involvement based on a retrospective analysis of our departmental database. Materials and Methods: Clinical presentation, diagnostic method, treatment, and outcome were analysed and compared with cases reported in the literature. Results: In total, we identified 1, 196 patients with classic KS, three (0.25%) of whom developed bone involvement. The patients were all male and the average age at onset of bone involvement was 81.3 years. All three patients had biopsy-proven anaplastic KS affecting a bone of the lower limb. Bone radiological features were non-specific in one patient, while in all patients magnetic resonance imaging revealed osteolytic lesions and/or a solid tumour. HHV8 genotype analysis was performed in two patients, and subtypes A and C were found. Conclusion: Bone involvement should be considered in patients with known KS presenting with bone pain.