gms | German Medical Science

Objective: We report a rare case of a 25-year-old male patient who presented with 2 months headache, acute diplopia and left sided ptosis by incomplete N. oculomotorius palsy caused by IgG4 associated sellar pachymeningitis mimicking hypophysitis. IgG4-syndrome is an rare syndrome which came to focus within the last years. It is an immune-mediated fibroinflammatory disease commonly defined by high levels of IgG4 with typical histopathological findings. IgG4 leads to cytokine induced organ fibrosis e.g. damage, mainly affecting inner organs. Rare cases of affected sellar meninges or the pituitary have been reported.

Method: MRI showed signs of lymphocytic hypophysitis with left accented contrast enhancement of pituitary region, as well as left sinus cavernosus. Baseline blood and CSF testing showed mildly elevated, unspecific inflammatory reaction. On day 7 after onset of neurological symptoms N. oculomotorius palsy became complete. The patient was transferred to our department with suspected haemorrhagic pituitary infarction. There was no change in acute MRI. Immediate transsphenoidal surgery was performed. Intraoperative findings showed thickened and inflammated sellar dura, pituitary tissue seemed normal. Under suspicion of inflammation 20 mg Triamcinolon were applied locally. Postoperatively N. occulomotorius palsy improved quickly, the patient received Hydrocortisone (15mg/d) over multiple months.

Results: Histopathological findings showed lymphocytic inflammation of sellar dura. There were no signs of pituitary gland inflammation. Further investigations of sellar dura revealed high levels of plasma cells, of which more than 40% expressed IgG4. There were no signs of tumor, granulocytic inflammation or tuberculosis. Systemic levels of IgG4 (0.18 g/l, standard 0.052-1.25 g/l) and absolute number of lymphocyte subpopulation was normal, but there was a significant increase in switched plasmablasts to 16% (standard to all naive B-cells 0.4-3.6%). There were no signs of hypopituitarism.

Conclusions: According to the literature, elevated levels over 40% plasma cells expressing IgG4 of histopathologically inflamed organ defines IgG4 syndrome. Little is known about therapy, the patient is improving under steroids but has high risk of recurrence because of male gender, young age and low systemic level of IgG4. This is one of the first case reports of IgG4 syndrome affecting sellar dura without affecting the pituitary gland. Yet there are few case reports on IgG4 syndrome affecting meninges.