[Giant cell tumor of the temporal bone--case report (author's transl)]

The majority of giant cell tumors occurs in the long bones, especially around the knee, and only 1.4-1.8% of cases are found in the skull. In this communication, a case of giant cell tumor of the temporal bone is reported because of a rarity of the lesion in the skull. The 37-year-old housewife was admitted to our clinic complaining of swelling in right temporal region which had gradually developed over a two-month period. On examination, there was a swelling about 5cm in diameter beneath right temporal muscle; its surface was smooth and its consistency was hard. Tenderness was found in its center. Routine x-ray of the skull showed osteolytic lesion in right temporal bone with relatively clear margins. Computed tomography demonstrated heterogeneously high-density mass in right temporal bone and right middle fossa. The tumor located mainly within the temporal bone at the middle fossa, and intracranial epidural space at the convexity. After bolus injection of contrast material, the tumor of temporal bone and the peripheral portion of the intracranial tumor were enhanced markedly. Right external carotid angiograms disclosed tumor stain in capillary and venous phases. Abnormal RI uptake was disclosed by bone scintigrams with 99mTC-methylene diphosphonic acid. Her preoperative diagnosis was calvarial tumor with intracranial extension. A right fronto-temporal osteoplastic craniotomy was performed. The tumor located within the temporal bone and in epidural space which invaded temporal muscle and underlying dura. The tumor was elastic soft and vascular with central necrosis. The tumor was extirpated totally including surrounding temporal muscle and dura. Microscopic examination of the operative specimen revealed giant cell tumor of the skull. Therefore, she was treated with 60CO irradiation (3,000 rads) to the temporal region. In the 13 months since the completion of treatment, there has been no sign of recurrence nor metastasis. Giant cell tumor of the skull were reviewed with special references to diagnosis and treatment. Computed tomographic findings of this tumor were also discussed briefly.