Intraepithelial carcinoma arising in an endodermal cyst of the posterior fossa.
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.
Operative Unit of Anatomic Pathology, A. Cardarelli Hospital, Naples, Italy.
Roberto
R
Monaco
Amedeo
A
Boscaino
Arturo
A
Di Blasi
Antonio
A
D'Antonio
Giovanni
G
Profeta
Raffaele
R
De Falco
Oscar
O
Nappi
D000328:Adult; D002278:Carcinoma in Situ / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D002471:Cell Transformation, Neoplastic; D020863:Central Nervous System Cysts / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D003937:Diagnosis, Differential; D004848:Epithelium / Q000473:pathology; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D015192:Infratentorial Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D019394:Ki-67 Antigen / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D011859:Radiography
D005904:Glial Fibrillary Acidic Protein; D019394:Ki-67 Antigen