Tumour-to-tumour metastasis of laryngeal leiomyosarcoma to an axillary hibernoma

Tumour-to-tumour metastasis is a rare, but well-recognised occurrence. This case report documents the metastasis of a primary laryngeal leiomyosarcoma to a hibernoma. We believe that this is the first recorded case of leiomyosarcoma metastasising to another neoplasm, and the first recorded case of a hibernoma acting as a recipient tumour for metastasis. This case study emphasises the importance of re-imaging a known benign mass in the presence of new symptoms in a patient with underlying malignancy, to ensure prompt diagnosis and management of potentially treatable metastasis. The imaging findings including whole body magnetic resonance imaging (MRI) staging, macroscopic and histological features are presented.