Ectomesenchymal chondromyxoid tumour: an uncommon characteristic tumour of the anterior tongue

Ectomesenchymal chondromyxoid tumor of the oral cavity: a report of 5 new cases with comprehensive review of the literature and clinicohistopathologic features

OBJECTIVE

An ectomesenchymal chondromyxoid tumor (ECT) is an uncommon soft tissue tumor with an enigmatic histogenesis and striking predilection for the tongue. We present 5 new cases and review the literature.

STUDY DESIGN

We performed a retrospective search for ECTs within the University of Kentucky Oral Pathology Biopsy Service and the published literature.

RESULTS

Five new cases from the biopsy archives and 103 well-documented ECT cases from the literature were compiled and reviewed. Whereas 89.8% of ECT are found on the anterior/dorsal/lateral/unspecified tongue, 4.6% are on the posterior/base of tongue. Six extralingual cases are reported. The age ranges from 2.3 to 78 years with an average of 40. Most ECT react with GFAP (92.8%) and S-100 protein (91.3%). Whereas 21/23 cases demonstrated a RREB1-MKL2 fusion, EWSR1 gene mutations are identified in 4 cases.

CONCLUSIONS

Most ECT are readily diagnosed on routine histopathology in combination with tumor site, immunohistochemical findings, and molecular findings; however, a subset share overlapping features with myoepithelioma of soft parts. As further molecular analysis is performed on this tumor, we may find that a subset of previously diagnosed ECT relate to or represent myoepithelioma or conversely fall under the spectrum of the pluripotent ECT.

Ectomesenchymal Chondromyxoid Tumor: A Rare Association With an Asymmetrical Soft Palate Cleft

Ectomesenchymal chondromyxoid tumor (ECT) is a rare oral lesion first described by Smith et al. in 1995. These tumors are typically painless, slow growing and benign masses occurring predominantly on the anterior tongue dorsum. Prior to this seminal report, many ECTs may have been misdiagnosed due to the histological similarities with other lesions. Immunohistochemical stains aid in definitive diagnosis of an ECT. A total of 39 papers since published have reported 96 patients with ECT. Most lesions involve the anterior aspect of the tongue, with only 6 occurring in the posterior tongue and 2 involving the hard palate. ECTs are considered to develop from ectomesenchymal cells of neural crest cells that have migrated to the tongue during embryological development. This paper is of a rare case of ECT of the posterolateral tongue occurring in association with an unusual asymmetrical soft palate cleft. It is postulated that since the tongue develops before the formation of the soft palate, an ECT lesion occurring on the posterior aspect may have a causal contribution to the development of the soft palate cleft.