Fluctuating bilateral abducent palsy leading to the diagnosis of pituitary mass without cavernous sinus involvement. How does this match?
Ilonka Kreitschmann-Andermahr1, Flverly Francis1, Michael Mull2, Christine Streetz-van-der-Werf3 & Franz-Josef Hans1
We report a 61-year-old lady with sudden onset diplopia caused by abducent palsy which was initially right- and later left-sided. MRI scanning revealed an extensive sellar and suprasellar mass and the lady was referred to our department for transphenoidal surgery with the imaging diagnosis of pituitary adenoma. Upon close inspection of the films, cavernous sinus invasion of the tumour as a morphologic correlate of the N. VI palsy was missing; however, there was an unusual contrast enhancement in the sphenoid sinus. Endocrinologic investigation gave evidence of partial anterior hypopituitarism. Because of the clinical and imaging incongruence, CCT was performed, revealing extensive metastatic infiltration of the skull base with osteoblastic and osteolytic elements. Tumour masses extended into the sphenoid sinus and the sellar and suprasellar space. The apex of the petrous bone both sides had osteolytic lesions explaining the bilateral abducent palsy. 18 years ago, the patient had been diagnosed with breast cancer with a local recurrence 5 years later. Because of the long tumour-free interval, the patient had failed to mention this part of her medical history at prior appointments. Further osseous metastatic lesions were diagnosed in the cervical spine and left hip. Radiotherapy of the metastases was initiated and up to now, 6 months after the initial diagnosis, the disease is stable. Breast and lung cancer are the most common primary tumours metastasizing into the pituitary. Diabetes insipidus or anterior hypopituitarism are frequent presenting symptoms, whereas oculomotor symptoms are less commonly observed.
This case illustrates the necessity for the treating physician to assure himself of the accordance of clinical and imaging features, and - if this is not given to initiate further examinations to come to the right diagnosis. CCT scan is a very useful imaging tool to uncover osseous changes which are not conspicuous on MRI.