Ectomesenchymal chondromyxoid tumor: histopathologic and immunohistochemical study of two cases without a chondroid component

Abstract

Ectomesenchymal chondromyxoid tumor (ECT) is a rare benign neoplasm usually affecting the anterior dorsum of the tongue. Histopathologically, it is formed by spindle, round and/or polygonal cells embedded in a chondromyxoid matrix. Immunohistochemical positivity for vimentin, S‐100 protein, glial fibrillary acid protein and neuron‐specific enolase are helpful to confirm the diagnosis. There are 42 cases of ECT of the tongue reported in the English language literature, three of them showing no chondroid matrix. We describe two additional cases of ECT lacking the chondroid component, exhibiting areas of reticulated myxoid and cellular pattern. Considering the microscopical features, ECT can be classified in classic and ‘chondroid‐free’ variants, the latter including the reticulated myxoid and cellular patterns. It is important to consider that the cellular ECT usually exhibits predominance of an infiltrative atypical cellular component that may mimic a malignant tumor. Palma Guzmán JM, de Andrade BAB, Rizo VHT, Romañach MJ, León JE, de Almeida OP. Ectomesenchymal chondromyxoid tumor: histopathologic and immunohistochemical study of two cases without a chondroid component.

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

“…Three cases showed chondroid differentiation. As opposed to our series, the majority of ECTs published in the literature showed chondroid tissue stroma (42/48, 87 %) [10,[13][14][15].…”

Ectomesenchymal chondromyxoid tumor with a significant proliferative index: A case report

“…2,5,8,[12][13][14][15][16][17] The clinical features of the present case are consistent with those reported in the literature, which describe the ECT as an asymptomatic lesion that usually measures less than 2 cm in diameter, is located on the back of the tongue and affects patients at a mean age of 34 years. 1,2,5,6,8,11,12,18,19 Histologically, the present case meets the morphological criteria for the diagnosis of ECT. 2,[4][5][6]8,11,15,[17][18][19][20][21][22][23] The tumor is characterized by a lobular growth pattern with cystic spaces and stroma with myxoid, chondroid and myxochondroid areas, and by hypercellularity -especially small cells, which seem to predominate in ECT.…”

Nodular lesion in the buccal mucosa

“…9 Ki-67 protein labeling is low, indicating the benign nature of the tumor. 2 The presence of biphasic myxoid and chondroid patterns and the positivity of tumor cells for vimentin, S100 protein, and GFAP are important findings for making the diagnosis of ECT. 12 The treatment for this tumor is conservative surgical excision.…”

“…9 ECT may exhibit focal areas of cellular atypia, including pleomorphism and mitotic figures. 2 The immunopathologic characteristics indicate a tumor of mesenchymal, neurogenic origin 11 with the expression of vimentin, S100 protein, and GFAP. ECT presents variable immunoreactivity for CD57, desmin, and SMA, as we observed in the case described in this article.…”

“…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.…”