Middle ear glandular neoplasms: adenoma, carcinoma or adenoma with neuroendocrine differentiation: a case series

Abstract

Introduction: Middle ear glandular neoplasms are infrequent causes of a middle ear mass. They can have exocrine and/or neuroendocrine differentiation. It is currently thought that these tumors are indistinguishable each from another. Herein, we present a new case of a middle ear glandular neoplasm. Our objective is to review all cases described in the literature in order to identify the clinical features, the gross pathology, the histopathology, the immunohistochemistry, to discuss the differential diagnosis, the treatment, the rate of recurrence, the follow-up, the incidence of metastasis, the prognosis and to present a new classification of middle ear glandular neoplasm.

‘Neuroendocrine’ middle ear adenomas: consistent expression of the transcription factor ISL1 further supports their neuroendocrine derivation

“…3 A plasmacytoid cell appearance seems to be infrequent, being observed in only one of our six cases and in a few previous cases. 2,3,24 This pattern was very striking on pancytokeratin and vimentin immunostaining, and may closely resemble rhabdoid neoplasms and some subtypes of pituitary adenoma. Although this pattern was seen only in a recurring case in our series, it is difficult to link it with a more aggressive course, owing to limited data on this variant in previous series.…”

“…3 In 2009, Saliba and Evrard described a new case, and reviewed 94 cases reported in 1950-2008. 2 Since then, some 20 cases have been reported in the English-language and German-language literature. [10][11][12][13][14][15][16][17][18][19][20][21][22][23] Thus, including our series, a total of~120 cases have been reported.…”

“…The frequency of expression of neuroendocrine markers has varied significantly among different studies (20-100%). 2,3 Most cases expressed pancytokeratin, CK7, and vimentin. It is noteworthy that cases devoid of any neuroendocrine marker expression in the AFIP series all had a pure glandular pattern, suggesting a non-endocrine variant among lesions classified as MEA.…”

“…Since its first description by Hyams and Michaels in 1976 as 'middle ear adenomatous tumour', 1~1 14 cases have been reported in the English-language literature under different names: middle ear adenomatous tumour, middle ear adenoma, neuroendocrine adenoma of the middle ear (NAME), neuroendocrine tumour of the middle ear, and carcinoid of the middle ear. 2 The plethora of names used for this lesion reflect the uncertainty and controversy regarding its derivation. Whereas, in the original report, an origin from mucosal epithelium of the middle ear was suggested, the frequent expression of neuroendocrine markers and the presence of mixed glandular and non-glandular histological features suggested an origin from undifferentiated pluripotential stem cells related to the neural crest.…”

“…Whereas, in the original report, an origin from mucosal epithelium of the middle ear was suggested, the frequent expression of neuroendocrine markers and the presence of mixed glandular and non-glandular histological features suggested an origin from undifferentiated pluripotential stem cells related to the neural crest. [1][2][3] Although some recent studies have pointed out that MEA and NAME represent the same entity, 2,3 the distinctiveness of MEA from other types of adenoma was not stressed in many of the older studies. Furthermore, some series included purely glandular lesions that turned out to be completely negative for neuroendocrine markers, and the histogenetic nature of these remained unclear.…”