Intraepithelial carcinoma arising in an endodermal cyst of the posterior fossa

Abstract

Endodermal cysts of the central neuraxis are benign, non-neoplastic epithelium-lined cysts arising from endodermal tissue that have been displaced early in fetal life. Intracranial endodermal cysts are rare and usually located in the posterior fossa. The present study involves a 36-year-old man with a typical epithelial cyst in the posterior fossa. Microscopically, the cyst has a simple columnar epithelium with mucus-producing cells, containing an area composed of dysplastic epithelium with evidence of an intraepithelial carcinoma. The atypical cells have a high proliferative fraction demonstrated by Ki-67 immunostain. Based on these findings, the authors view this case as evidence of a malignant transformation of a classic endodermal cyst. The clinicopathologic features and a review of the literature are discussed.

Malignant Transformation of a Neurenteric Cyst in the Posterior Fossa Presenting with Intracranial Metastasis: A Case Report and Literature Review

“…1) Other than the cases of originally malignant neurenteric cysts, [7][8][9][10][11] the malignant transformation of benign neurenteric cysts is extremely rare. [12][13][14] In this report, we describe a case of a neurenteric cyst in the posterior fossa that eventually showed malignant transformation and intracranial metastasis and review of the relevant literature.…”

Recurrent intracranial neurenteric cyst with malignant transformation: A case report and literature review

“…The age of the 9 patients with NC and malignant transformation ranged between 25-60 years (6,(9)(10)(11)(12)(13)(14). To the best of our knowledge, no patients have been reported with malignantly transformed NC during childhood.…”

“…NCs, also called enterogenous (13,15), enterogenic (17), endodermal (14) or archenteric (18) cysts, are congenital lesions of presumed ectodermal origin that rarely appear in the cranio-spinal axis. The precise pathogenesis of NCs remains unclear.…”

“…To the best of our knowledge, very few reports have described this unusual phenomenon (9)(10)(11)(12)(13)(14)(15)(16). Therefore, the demographic characteristics, treatment and prognosis of this type of NC is not clear.…”

Surgical Strategy for Intracranial Endodermal Cyst-Two Case Reports-

“…One case of endodermal cyst in the foramen magnum became adenocarcinoma 3.5 years after the initial resection, 19) a case of an extra-axial multilobulated tumor transformed to a well-differentiated papillary adenocarcinoma, 8) and a case of endodermal cyst showed malignant transformation to an intraepithelial carcinoma. 13) Malignant transformation of the endodermal cyst is probably very rare, but a small number of endodermal cyst have possibly been diagnosed as craniospinal adenocarcinoma of unknown origin.…”