Relapse of Multiple Myeloma Presenting as Lower Lip Numbness.

Multiple myeloma (MM) is an uncommon malignancy characterised by the proliferation of clonal plasma cells. There are few published reports describing the extramedullary presentation of MM manifesting primarily in the head and neck region. In addition, the occurrence of an isolated relapse of MM in these sites is exceedingly rare. We report a 56-year-old female who presented to the Sultan Qaboos University Hospital, Muscat, Oman, in 2010 with sudden-onset numbness of the lower lip. She had a history of MM in remission following chemotherapy and a bone marrow transplant. Clinical and radiographic examinations were indicative of a possible relapse of MM, which was subsequently confirmed by bone marrow aspiration and histopathological evaluation. This unique case highlights the unusual site of relapse of a haematolymphoid malignancy.