ABSTRACT
We present an unusual patient with a medical history of a fibrosing pseudotumor of the left orbit that had been stable for 8 years who presented with acute anterior hypophyseal failure. During the next 10-month period, sequential magnetic resonance scans showed a rapid growth of a plaque-like sellar and parasellar mass extending into the right cavernous sinus, right Meckel's cave, along the dural surfaces of the clivus, dens, and body of the second cervical vertebra. A transsphenoidal biopsy revealed sphenoid and intrasellar pseudotumor that invaded the adenohypophysis and had microscopic features identical to those of the previously excised orbital pseudotumor. Rapid growth of the pseudotumor continued despite a course of radiotherapy. Palsies of cranial nerves V and VI and of the sensory root of the cranial nerve VII developed on the right side. Steroid therapy was associated with improvement of the cranial nerve palsies. This is the first report of the sellar fibrosing pseudotumor producing not only anterior hypophyseal failure, but also cranial nerve dysfunction secondary to plaque-like extension into the cavernous sinus, Meckel's cave, and cranial base dura. This intracranial plaque-like extension of a fibrous pseudotumor corresponds to a hypertrophic intracranial pachymeningitis, which is a rare, previously described phenomenon associated to the syndrome of multifocal fibrosclerosis.