title: [Intracranial collision tumor--A case report (author's transl)].
abstract: A 21-year-old man with nasopharyngeal tumor was  first admitted to the Nagoya University Hospital on April 15, 1972. He had difficulty in speaking and swallowing, and developed double vision prior to admission. A soft and yellow tumor was found in the nasopharynx and revealed typical features of chordoma. The patient underwent Co60 irradiation after the operation. On January 25, 1973, the patient developed double vision of severe degree. Microscopic examination of the specimen which was obtained at the time of the second operation in February 9, 1973, disclosed a coexistence (collision) of chordoma and hemangioblastoma. The two different tumors were situated in juxtaposition on histological examination. Co60 irradiation was added during his second hospitalization. Three months after the second operation, he developed symptoms of meningitis and was hospitalized for the third time on June 3, 1973, at which time the tumor tissue extended through the right frontal and middle fossa. The third operation was done with frontal craniotomy and tumor was partially removed. The histological diagnosis was hemangioblastoma. Postoperatively the patient went downhill and died on September 19, 1973. The report of a collision tumor of intracranial chordoma and hemangioblastoma is not found in the previous literature. There have been many theories as to the origin of collision tumor. Some investigators have proposed that the existence of hyperplastic blood vessels within the glioblastoma is responsible for the collision tumor of sarcoma and glioblastoma. Since the advent of radiotherapy, several examples of sarcoma have been discovered at postmortem examination in patient irradiated for treatment of cerebral neoplasm, both gliogeneous and nongliogenous, suggesting a possible relationship between the tumor and the radiation therapy. In our case, the chordoma showed neither hyperplastic blood vessels nor malignant pattern on histological examination. It was suspected that post-operative radiation induced the hemangioblastoma. The etiology was discussed from the review of literature.
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000473:pathology* / Q000532:radiotherapy; D002817:Chordoma / Q000473:pathology* / Q000532:radiotherapy; D006394:Hemangiosarcoma / Q000473:pathology*; D006801:Humans; D008297:Male; D009378:Neoplasms, Multiple Primary / Q000473:pathology*; D011878:Radiotherapy / Q000009:adverse effects