Management of Low-Grade Papillary Adenocarcinomas of the Endolymphatic Sac

Objective: To optimize the treatment of low-grade adenocarcinomas of the endolymphatic sac. Design: Retrospective study. Materials and Methods: We retrospectively reviewed clinical, immunohistopathological, radiological, and surgical records of two groups of cases of ELSTs. Seven cases were managed by the Istituto Clinico Humanitas (Rozzano, Italy), and four were managed at Ospedale, Legnano, Italy. Results: Smaller tumors localized to the endolymphatic sac area and adjoining the posterior fossa can be dealt with by a transmastoid-retrolabyrinthine approach. Translabyrinthine is a convenient approach for tumors that involve the inner ear and mastoid bone, while an infratemporal fossa approach is preferred for bigger lesions when tumor involves the facial nerve, the jugular bulb, and the middle ear. A transcochlear approach is needed when complete exenteration of the otic capsule and the exposure of petrous carotid artery are necessary due to extensive tumors. A combined transtemporal-retrosigmoid approach gives adequate exposure for tumors involving posterior and middle cranial fossa. One case of the first group received irradiation with minimal size change of the recurrence; all cases of the second group received irradiation in the surgical field. Conclusions: Sporadic ELST is a low-grade malignant neoplasm because it has the feature of local spread—one case we found a distant metastasis. Early detection and complete extended surgical removal at first attempt result in lasting cure, while subtotal removal usually results in recurrence. Radiation therapy seems to have a limited role in the management of unresectable recurrences.