Ectomesenchymal Chondromyxoid Tumour of the Posterior Tongue

Abstract

Ectomesenchymal chondromyxoid tumor (ECMT) is a rare benign neoplasm arising in the tongue. With only 45 cases reported in the literature, there are several unique features defining this lesion. Firstly, almost all patients present with an asymptomatic slow growing mass on the anterior dorsum of the tongue. At the microscopic level, it is recognizable as a well-circumscribed unencapsulated proliferation of uniform round to fusiform cells embedded in a chondromyxoid matrix. Lastly, the immunohistochemistry profile is characterised by positivity for glial fibrillary acidic protein and frequent positivity for S-100 and cytokeratins. We report a case of a mass located on the posterior dorsum of the tongue and meeting the aforementioned morphological and immunohistochemical criteria of ECMT.The patient is a 43 year old male who presented to the Ears Nose and Throat clinic at the McGill University Health Center with odynophagia and mild dysphagia that had been present for 3 months. He did not have any significant prior medical or family medical history, did not take medications, and did not smoke or consume alcohol. The patient felt a slowly growing mass at the back of his throat that would occasionally trigger a gag reflex and the sensation of narrowing of his throat. He had mild dysphagia but retained normal tongue strength, range of motion and sensation. On examination, an exophytic mass was visible on the back of the tongue that crossed the midline and was soft on palpation. The mass obliterated the space between the uvula and the palatoglossal arch.A CT scan without contrast was performed which showed a large cystic appearing mass at the tongue base (Fig. 1). A fine needle aspiration of the mass produced 15 mL of red fluid. A cell block of the fluid was prepared and showed whorls of spindled cells with alternating hypercellular and hypocellular areas with scattered thinwalled vessels. Nuclear atypia was minimal and no mitotic figures were identified. Immunohistochemistry of the cell block showed positive staining for vimentin, GFAP, cyclin D1, synaptophysin and CD57. Desmin, factor VIII, myogenin and epithelial membrane antigen (EMA) staining were weak and/or patchy. Cytoplasmic beta-catenin staining was seen, but without nuclear stain. Immunohistochemistry was negative for cytokeratin (CK) AE1/AE3, CK5/6, p63, p16, HMB-45, CD34, CD31, c-kit, smooth muscle actin (SMA), bcl-2, factor XIIIa, calponin, neurofilament, S-100 and chromogranin. A low grade mesenchymal neoplasm was favored over a salivary gland neoplasm, and it was recommended that the patient have local resection for definitive diagnosis.For the surgery, a mouth gag was introduced and the oral cavity was visualized. The tongue was grasped and a tonsillectomy gag was placed in the oral cavity to expose the base of the tongue. With the tongue retracted, the tumor

Ectomesenchymal Chondromyxoid Tumour of the Dorsal Tongue Presenting with Impaired Speech

“…Similarly to Smith et al's original findings, the vast majority of subsequently described ECTs have been documented on the anterior tongue surface, although there are a handful of cases in which tumours have been located on the posterior aspect of the tongue [1, 5] and one case where the neoplasm grew on the hard palate of a 13-year-old boy, described by Gouvêa et al in 2012 [6]. There was another reported case of ECT on the hard palate reported in 2006; however, the diagnosis in this case has been the subject of controversy due to an apparent lack of appropriate documentation [7].…”

“…Ectomesenchymal chondromyxoid tumours (ECTs) are rare mesenchymal soft tissue neoplasms that typically present as a slow-growing asymptomatic mass on the anterior dorsum of the tongue, or, much less frequently, on the posterior tongue [1]. Microscopically, ECTs are identified as unencapsulated, well-circumscribed proliferations of uniform round to fusiform cells embedded within chondromyxoid matrices [1].…”

“…Microscopically, ECTs are identified as unencapsulated, well-circumscribed proliferations of uniform round to fusiform cells embedded within chondromyxoid matrices [1]. ECT has affected patients 7 to 78 years old and classically appears in the third through sixth decades of life, with literature review revealing no sex predilection.…”

Nodular lesion in the buccal mucosa

“…ECT was first described in 1995, 1 with 52 cases reported in the English-language literature: 50 cases were in the tongue; 1 was in the hard palate; and 1 was in the buccal mucosa. [1][2][3][4][5][6][7][8] The cases described in the literature reported that ECT most commonly affects adults in the third to sixth decades of life. Clinically, ECT presents as a slow-growing, painless, firm, wellcircumscribed, submucosal nodule, covered by normal mucosa, that appears to involve only the oral cavity and usually is located on the anterior dorsum of the tongue.…”

A subset of ectomesenchymal chondromyxoid tumours of the tongue show EWSR1 rearrangements and are genetically linked to soft tissue myoepithelial neoplasms: a study of 11 cases

“…The authors who first described this tumour supported an ectomesenchymal (neural crest) origin, owing to the strong and diffuse tumour cell immunoreactivity for S100 and glial fibrillary acidic protein (GFAP) . An origin from minor salivary glands appears to be less likely, because of the absence of minor salivary glands in the anterior tongue dorsum. Also, the immunophenotype of the neoplastic cells differs from that of salivary myoepithelial tumours …”