Chondroma of the petrous apex

Surgical Removal of Chondroma of the Petrous Apex Resulting in Hearing Improvement -Case Report-

“…Chondromas in the parasellar area often cause impairment of cranial nerves II, III, IV, V, and VI, whereas chondromas of the petrous apex cause symptoms in the internal carotid artery, the mandibular division of the fifth cranial nerve (V3), the abducens nerve (VI), and the internal auditory canal structures. 2,4,6,8,10,13,14) In our case, we observed progression of hearing impairment, and preoperative imaging demon-Neurol Med Chir (Tokyo) 50, February, 2010…”

“…Chondrocytes are believed to form cartilage tumors because they ossify as immature cells, without passing through normal degenerative processes. 1,8,15) Intracranial chondromas can be classified into (a) sinus chondromas, (b) chondromas of the convexity and intracranial structure, and (c) basal chondromas, arising at the junction of the sphenopetrosal, petro-occipital, and spheno-occipital synchondroses. 15) However, the vast majority are basal chondromas located in the skull base, especially in the parasellar area and middle fossa.…”

“…Chondromas occurring in the petrous apex are very rare, with only 7 cases reported. 2,4,6,8,10,13,14) Chondromas generally grow slowly, so neurological symptoms are delayed, but unilateral localized neurological symptoms caused by pressure and corresponding to the location of the tumor often appear. Chondromas in the parasellar area often cause impairment of cranial nerves II, III, IV, V, and VI, whereas chondromas of the petrous apex cause symptoms in the internal carotid artery, the mandibular division of the fifth cranial nerve (V3), the abducens nerve (VI), and the internal auditory canal structures.…”

“…3,5,7,16) However, in cases like ours, where the chondroma is confined to the petrous apex instead of occurring in the parasellar or pericavernous areas or the middle fossa (where chondromas tend to occur), the differential diagnosis also includes cholesteatoma and chondrosarcoma. 8,9) Surgical removal is the standard treatment because radiation therapy is ineffective. If complete removal is accomplished, a favorable course of the disease and long-term prognosis can be expected, 12) but if the tumor occurs in the skull base or cavernous sinus, complete removal is difficult.…”

“…Only 7 cases of chondroma occurring in the petrous apex have been reported. 2,4,6,8,10,13,14) Complete surgical removal is often difficult for chondroma occurring in the skull base and in the cavernous sinus. However, partial removal to reduce pressure seems to be adequate, since chondromas rarely invade the nerves or blood vessels directly.…”