title: Adenocarcinoma arising from intracranial recurrent mature teratoma and featuring mutated KRAS and wild-type BRAF genes.
abstract: Malignant transformation or recurrence of intracranial mature teratoma is an extremely rare occurrence, compared to the usual ovarian counterpart. Previously, yolk sac tumor elements have been considered to be selective progenitors of enteric-type adenocarcinoma arising from intracranial germ cell tumors. However, the present case demonstrates the occurrence of enteric-type adenocarcinoma in recurrent intracranial mature cystic teratoma 12 years after gross total removal, a case of which has not previously been documented in the literature. The 11.5-cm long, dura mater-based tumor on the right fronto-temporal lobe displaced the brain; however, the patient had no neurologic symptoms or discomfort other than pus-like discharge on the scalp. Microscopic examinations revealed a small focus of adenocarcinoma and dysplastic colonic mucosa in the mature cystic teratoma. No immature elements were seen. The cystic wall was almost denuded and showed an exuberant xanthogranulomatous reaction with foreign-body type giant cells engulfing keratin materials and cholesterol clefts, suggesting that chronic inflammation due to repeated cyst wall rupture and the previous resection may contribute to malignant transformation. The adenocarcinoma showed strong immunohistochemical expression of CK20 and p53, but CK7 in patches. The molecular profile of the adenocarcinoma showed a mutation in KRAS and wild-type BRAF, which might be associated with malignant transformation of intracranial mature teratomas. In conclusion, the intracranial mature teratomas should require long-term follow-up, and clinicians, radiologists and pathologists should be aware of the potential for malignant progression of recurrent intracranial mature cystic teratoma despite gross total resection and no neurologic symptoms.
authors.affiliation: Department of Radiology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Republic of Korea.
authors.forename: Eun Soo
authors.initials: ES
authors.lastname: Kim
authors.forename: Mi Jung
authors.initials: MJ
authors.lastname: Kwon
authors.forename: Joon Ho
authors.initials: JH
authors.lastname: Song
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Kim
authors.forename: Hye-Rim
authors.initials: HR
authors.lastname: Park
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology*; D001932:Brain Neoplasms / Q000235:genetics / Q000473:pathology*; D002471:Cell Transformation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000473:pathology*; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D013724:Teratoma / Q000235:genetics / Q000473:pathology*; D018631:ras Proteins / Q000235:genetics*
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins
keywords: adenocarcinoma; dura mater; immunohistochemistry; mature teratoma; recurrence