Ectomesenchymal Chondromyxoid Tumor: A Series of Seven Cases and Review of the Literature

Abstract

Ectomesenchymal chondromyxoid tumors (ECT) are rare, benign, intraoral mesenchymal soft tissue tumors that can be diagnostically challenging. In this study the demographic, clinical, histopathologic, and immunohistochemical features of seven ECTs are examined. The differential diagnosis of this rare neoplasm is discussed and the literature is reviewed.

Ectomesenchymal Chondromyxoid Tumour of the Dorsal Tongue Presenting with Impaired Speech

“…The tumour's presence and growth ranged in duration from a few months to 10 years, and tumour size ranged from 0.3 cm to 2.0 cm [4]. A more recent review of 7 cases of ECT in 2015 reported an age range of 7 to 57 years, with a median age of 45.8 years, and the duration of the tumours was reported as “only available on two cases and ranged from six months to several years,” with sizes that ranged from 0.6 × 0.7 cm to 1.2 × 2.0 cm [2]. It is likely difficult to gauge the duration of this neoplasm considering its nonpainful, asymptomatic nature and tendency to grow slowly.…”

“…This follows from Smith et al's original inclusion of this marker in their introductory report on ECT [4]. Indeed, according to the recent review by Aldojain et al and the compilation of several other cases by Shogo and Koda, it is reported that 75–80% of cases of ECT show positivity for CD57 [2, 8]. Shogo and Koda argued that CD56 would be a useful adjunct in diagnosing ECT [8], considering it has been shown to be a more useful marker of neurogenic lineage compared to CD57 [9] and also tends to be more readily available in pathology laboratories.…”

“…However, this lack of definition of ECT's features likely also results from it being confused with or mistaken for other entities that share some of its histopathological features. Entities to include in the differential diagnosis include myoepithelioma, nerve sheath myxoma, mucocele, pleomorphic adenoma, oral focal mucinosis, glial choristoma, ossifying fibromyxoid tumour, chondroid choristoma, soft tissue myxoma, and cellular neurothekeoma [2, 10, 11]. The development and refinement of immunohistochemistry studies, and the identification of specific molecular markers, have allowed pathologists to distinguish ECT from other entities in the differential diagnosis.…”

“…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. In the literature, ECTs have generally ranged in size from 0.6 to 0.7 cm to 1.2 to 2.0 cm in diameter [2], with very rare exceptions of much larger tumours reported [3]. We report a description of a 1.5 by 2.5 cm ECT presenting on the anterior dorsal tongue surface, accompanied by a dramatic preoperative photo.…”

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

“…Histopathologically, ECT is characterized by unencapsulated, well‐circumscribed proliferation of round, oval, polygonal or spindle cells with ill‐defined eosinophilic to faintly basophilic cytoplasm. Tumour cells are arranged in cords, strands, and sheets, and they are embedded in a chondromyxoid stroma . 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) .…”