From Volume 44, Issue 1, January 2017 | Pages 53-54
This is a case of a patient presenting to his general dental practitioner (GDP) with altered sensation in his lower lip with no obvious cause. Due to a prompt referral, the patient was investigated and diagnosed with an extramedullary presentation of multiple myeloma. A numb lip can present in general dental practice, although this is not common. There are several causes, for example, dental infection or fractured mandible.
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.
The FNA demonstrated a monotonous population of cells that had a plasmacytoid appearance with eccentrically placed nuclei, suggestive of recurrent myeloma (Figure 2). He was referred back to the Haematology Department and treated with chemotherapy (lenalidomide) and dexamethasone. A second stem cell transplant is not being considered due to his early relapse.
Multiple myeloma (MM) is a plasma cell neoplasm. There is proliferation of plasma cells in the bone marrow, which produce excess immunoglobulin. The neoplastic plasma cells replace normal bone marrow. Plasma cell tumours are known as plasmacytomas. These can present as solitary lesions, solitary plasmacytoma or, as in the case of multiple myeloma, multiple lesions. The solitary lesions are divided into two categories:
SBPs are more likely to transform to MM than EMPs. Diagnostic criteria for MM includes the presence of monoclonal protein, an abnormal protein, in serum or urine and >10% clonal plasma cells in a bone marrow biopsy.2
Multiple myeloma is more common in men and generally occurs between the age of 65 and 70.
Of EMPs, 80% occur in the head and neck region,1 the most common presenting symptoms being epistaxis, rhinorrhoea, sore throat, dysphonia and haemoptysis.1,3 In this case, the presentation of unilateral paraesthesia of the lower lip is not common and represented the patient's first symptom of recurrent disease.
The extramedullary presentation in this case was secondary to a known history of multiple myeloma. Although rare, oral and maxillofacial lesions can be the first presentation of multiple myeloma.4 It is essential that symptoms, such as paraesthesia, with no obvious cause are recognized as potentially sinister. Early referral ensures a hastened diagnosis and prompt treatment.
Historically, the treatment of choice for EMP has been radiotherapy but outcomes may be improved if this is combined with surgery.5 In this case, this was not considered, as the EMP was secondary to MM.
Numbness of the lower lip and tongue can be an uncommon post-operative complication following extraction of posterior teeth6 and also with fractured mandible. However, in the absence of these, the serious implication of this sign must be recognized and referral made under the two-week rule referral system in the UK or equivalent referral system in other countries.
