Case report: metastatic infratemporal soft tissue myeloma presenting as a numb lower lip

A 68-year-old male was referred to the Oral/Maxillofacial Department by his GDP with a three month history of altered sensation in his right lower lip. The patient noticed a reduced sensation when touching his lower lip, only affecting the right side. Over several weeks this became more profound with an almost complete loss of sensation to the lower right lip. A change in sensation in the right side of the tongue also became apparent to the patient. He had also noted a lump developing in his right parotid gland which, on presentation, was approximately 3 cm x 3 cm. He also had subtle weakness of his right marginal mandibular division of the facial nerve (House-Brackman classification 1). There was no palpable lymphadenopathy. There was no history of recent dental extraction or trauma.

The patient had been diagnosed with multiple myeloma three years previously, which was treated with chemotherapy and a stem cell transplant. He had been in remission with no evidence of recurrent disease. Investigations included magnetic resonance imaging (MRI) and a fine needle aspirate (FNA) of the lump. The MRI scan demonstrated a 50 x 35 x 25 mm mass in the right masticator and deep parotid space involving right mandibular ramus and pterygoid muscles (Figure 1a and b). Involvement of the mandibular nerve was likely as it passed through the masticator space. The differential diagnosis included a large myelomatous deposit, chondrosarcoma or a lymphoma.