Reclassification of aggressive adenomatous mastoid neoplasms as endolymphatic sac tumors

Abstract

The emerging concept that aggressive adenomatous tumors of the temporal bone arise from the endolymphatic sac and constitute a distinct clinicopathologic entity merits wider recognition. These tumors share a common clinical pattern and exhibit consistent imaging and histopathologic features. Endolymphatic sac tumors (ELSTs) have been mistaken for other neoplasms such as paragangliomas, adenomatous tumors of mixed histology, ceruminomas, and choroid plexus papillomas. A review of the literature shows similarities among case studies of these aggressive adenomatous lesions. An analysis of the data supports the endolymphatic sac as an origin for these tumors. This report also presents an additional case of a less differentiated variant of this rare but important clinicopathologic entity.

Endolymphatic Sac Tumor Associated with a Von Hippel-Lindau Disease Patient: An Immunohistochemical Study

“…Normal endolymphatic sac shows papillary epithelium composed of cuboidal or columnar cells and has neuroectodermal origin (22). ELST histologically corresponds to this feature and, therefore, has been supposed to express neuroectodermal markers (2,12). Immunoreactivity for neuron specific enolase in the present case supports this hypothesis.…”

“…It often shows invasion to surrounding temporal bone (3,4,12) and there are reports of several patients who received incomplete resection and experienced a recurrence of the tumor (7,21), although proliferative activity has been unknown in most ELSTs.…”

A histopathological connection between a fatal endolymphatic sac tumour and von Hippel–Lindau disease from 1960

“…4 In 1993, Li et al proposed reclassifying all adenomatous tumours of the endolymphatic sac as endolymphatic sac tumours, to better delineate them from other neoplasms affecting the temporal bone. 5 Endolymphatic sac tumours occur sporadically or as a part of von Hippel-Lindau disease. von Hippel-Lindau disease is an autosomal dominant disorder, with a prevalence of 1 in 36 000 live births.…”

Treatment of endolymphatic sac tumour (Papillary adenocarcinoma) of the temporal bone

“…14 Various skull base approaches used in different series were: transmastoid, suboccipital craniotomy, translabyrinthine, infratemporal fossa, transcochlear, combined suboccipital and transmastoid, combined translabyrinthine and suboccipital, combined infratemporal and transcochlear, combined infratemporal and translabyrinthine, combined translabyrinthine and transcochlear, retrolabyrinthine presigmoid, retrolabyrinthine retrosigmoid, temporoparietal craniotomy, combined petroccipital with transsigmoid and translabyrinthine, combined suboccipital with transsigmoid and posterior infratemporal, and combined translabyrinthine and transsigmoid. 8,[13][14][15][16][17][18][19][20] With a complete resection of the tumour the long term prognosis of these patients are good. 8,[13][14][15][16][17][18][19][20] …”

“…8,[13][14][15][16][17][18][19][20] With a complete resection of the tumour the long term prognosis of these patients are good. 8,[13][14][15][16][17][18][19][20] …”