Abstract
Chondromyxoid fibroma (CMF) is an extremely rare lesion of the skull base. This histologic
type typically predilects metaphysis of the long bones. It is locally invasive/infiltrative,
and this tendency is more concerning in the skull base, where a radical resection
is often technically impossible because of the presence of vital neurovascular structures.
We present a case of a 19-year-old woman who presented with a sudden onset of right
facial weakness, progressively worsening to a severe disfiguring motor weakness. Gadolinium-enhanced
brain magnetic resonance imaging showed an osteolytic lesion located in the right
mastoid involving the stylomastoid foramen and the right seventh cranial nerve. A
partial mastoidectomy was performed, with an excellent rate of tumor resection and
complete local control of the disease at follow-up. The analysis of current literature
indicates that a radiologic diagnosis is rarely strictly convincing of CMF. Histologic
diagnosis is often difficult due to the lack of a specific immunohistochemical pattern
of chondrosarcoma. Surgery is currently recognized as the mainstay to manage this
lesion, although a trend toward adjuvant radiation therapy (RT) currently is seen.
Although a tendency of local recurrence is well recognized in the literature, the
very slow and indolent behavior of this lesion plus the trend to enhance local control
of the disease with high-dose RT pushed us to a reappraise the role of radical skull
base surgeries burdened by the risks of major complications, cosmetic deformities,
and additional neurologic deficits.
Keywords
chondromyxoid fibroma - temporal bone - facial nerve palsy - MRI - facial nerve canal
tumor
