Abstract
Introduction Motor neuron disease may present with isolated bulbar dysfunction but, in these circumstances, more treatable differential diagnoses should be considered. Further investigations may be indicated, if typical clinical signs are absent. We present an unusual case of a large tongue lipoma, presenting as dysarthria, referred to the motor neuron disease clinic.
Case Report A 72 year old right handed female retired librarian presented with a 1 year history of dysarthria and intermittent dysphagia. She had a past medical history of familial hypercholesterolemia, benign essential tremor and depression. Examination revealed dysarthria, and a chronic right ptosis without opthalmoparesis or fatigability. There were no tongue fasciculations, no wasting and tongue palpation was normal. Other than a benign tremor, the remainder of the neurological examination was normal.
Cranial MRI had been reported normal. Acetylcholine receptor, Anti-muscle-specific kinase and antiganglioside antibodies were negative.Nerve conduction and electromyography studies were normal.
The lack of progression and absence of positive clinical signs of denervation prompted an MRI of the neck. This revealed a 61x58x56mm glottic lipoma lesion replacing the entire tongue. In retrospect, this was visible on the previous cranial MRI. She was referred to otolaryngology.
Conclusion Tongue lipomas are rare, comprising 4.4% of benign oral neoplasms, and 0.3% of all tongue neoplasia. Clinical examination may be unrevealing. Large lipomas can present with dysarthria and dysphagia, and so are a rare differential diagnosis for motor neuron disease in cases who do not progress as anticipated. Review of soft tissue structures on cranial MRI is essential.
