Carcinoma of the tongue mimicking bulbar amyotrophic lateral sclerosis

Abstract

presenting with bulbar-onset amyotrophic lateral sclerosis (ALS), with only minor signs of denervation at the tongue electromyography (EMG), in whom continuous follow-up led to the discovery of a carcinoma of the tongue. We recently observed a 77-year-old man affected by progressive dysarthria, dysphonia, dysphagia and sialorrhea associated with significant weight loss. Neurological examination showed paralysis of the tongue, without atrophy or fasciculations. The other cranial nerves were normal. The proximal muscles of the four limbs and the respiratory muscles were slightly weak. The deep tendon reflexes were increased. A right plantar response in extension was present. Cerebellar and sensory functions were normal. Blood examination showed normocytic–normochromic anaemia and hypoproteinaemia. The CSF was normal. The EMG study showed minor denervation signs on the left anterior tibial muscle, the other examined muscles being normal. The absence of atrophy or fasciculations in the tongue, as in other voluntary muscles, and the lack of reproducible neurophysiological evidence of denervation, prompted us to perform further diagnostic tests. A CT scan of the neck showed an extensive and inoperable tumour involving the base of the tongue and the muscles of the floor of the mouth. At biopsy, an epidermoid carcinoma was diagnosed. Percutaneous endoscopic gastrostomy, tracheotomy and radiotherapy were carried out. Two months later the patient died from severe tongue bleeding. The tongue is the most common site of oral cancer. Symptoms include dysphagia, dysarthria, neck masses, ear pain and weight loss [2]. Diagnosis is often performed in advanced disease stages, because the symptoms are common to many other conditions [3]. In conclusion, our case supports the view that a tongue carcinoma should be considered in the differential diagnosis of bulbar-onset ALS, particularly when clear denervation on EMG or atrophy of the tongue are absent.