Pituitary Ganglioneuroma: Case Report and Literature Review

We present a case of pituitary ganglioneuroma occurring in a 25 year old woman who presented with headache and hemianopsia. The histologic, immunohistochemical, and ultrastructural features of this tumor support the view that these rare hypothalamic-pituitary tumors are independently functioning neurohormonal units. Immunostaining is strongly positive for neuron-specific enolase (NSE) in all tumor cells and cell processes and for synaptophysin in a few cells and fibers. Few cells closely associated with tumor cells are positive for S100 protein. The cell processes are positive for neurofilament antigen. Ultrastructural analysis documents a spectacular neoplasm of neural derivation. The tumor consists of ganglion cells and areas of neuropil. The most typical tumor cells have relatively lucent spherical nucleus with large nucleolus, and abundant cytoplasm harbors compact sacks of RER membranes studded with ribosomes. Particular emphasis is given to the ultrastructural features which strongly support the functional relationship between the tumor components. It should be kept in mind that unusual and rare ganglionic tumors might show a progressive clinical course and needs surgical intervention as the major part of their treatment whereas ontogenetic and pathogenetic mechanisms taking part still need more work to enlighten pituitary neuronal tumorigenesis.