[A case of enchondroma of the skull base--a manifestation of generalized chondromatosis (author's transl)].

Cartilaginous tumors arising from the skull or intracranial structures are infrequently seen. There have been 112 such cases reported. They are most commonly found in the middle fossa and the parasellar region. They arise from cartilaginous rests in the base of the skull, particularly around the basal synchondroses. Occasional cases of intracranial growths also show lesions in peripheral bones. The authors have encountered a case in which chondroma was a manifestation of generalized chondromatosis. The patient was a 25-year-old male, who complained of diplopia in May 1975. He noted ptosis in his left eyelid which gradually progressed over a 2 months period to complete ptosis. When he was admitted in July 1975 to Nagoya National Hospital, the neurologic signs revealed a palsy of the IIIrd cranial nerve on the left side. The patient has been suffering from generalized enchondromatosis during a period of 20 years. Roentgenograms revealed extensive areas of bone destruction and pathological calcification of the phalanx, ribs, hip bone, femur, tibia, ulna and radius. Roentgenograms of the skull revealed calcification on the left middle fossa. After a left carotid angiography, an osteoplastic craniotomy was performed on August 5, 1975. The tumor was located in the extradural space of the middle cranial fossa. After incision of the capsule, gelatinous semisolid tissue was removed piecemeal. Its total removal proved to be impossible. Histological examination of this tumor revealed enchondroma.