Presentation
Headaches and hypopituitarism
Patient Data
There is a 13 x 24 x 18 mm (AP x trans x CC) sellar and suprasellar mass. It is intermediate in signal intensity pre-contrast. There is avid post-contrast enhancement except for its a few small nonenhancing foci. No diffusion restriction is appreciated. The floor of the sella flattened and remodeled.
The mass compresses the optic chiasm against the hypothalamus, splaying the optic nerves. The cavernous internal carotid arteries are displaced medially, but remain normal in caliber. The left cavernous sinus is bulky with prominent enhancing tissue superiorly suspicious for tumor invasion. The margins of the tumor are ill-defined with irregular enhancement extending into the hypothalamic region as well as onto the surface of the tent.
No gross abnormality is detected in the remainder of the imaged brain, but please note that this study has been targeted to the pituitary, and as such the whole brain has not been imaged.
The patient went on to have a transphenoidal resection.
Histology
MICROSCOPIC DESCRIPTION: Sections show small fragments of dense fibrous tissue with scattered clusters and distorted acini of functioning pituitary cells (GH and Prolactin positive). There is infiltration and destruction of pituitary acini by CD3, CD4 and CD8 positive T-cells. Small sheets of necrotic tissue are seen adjacent to the tissue. Occasional small clusters of histiocytes are identified but no clearly discernable granulomas are seen. No mycobacteria or fungi are identified on ZN and PAS stains. There is no evidence of malignancy.
DIAGNOSIS: Features favoring an autoimmune lymphocytic hypophysitis.
Case Discussion
This case illustrates features of lymphocytic hypophysitis, with an extensive mass lesion and involvement of the adjacent dura.