A Spontaneous Ganglioneuroma in the Adrenal Medulla of a Young Wistar Hannover Rat

A nodule was observed in the adrenal medulla of a twenty-week-old male Wistar Hannover rat. The nodule was predominantly (over 80%) composed of neural components, with ganglion cells scattered in sparse supporting tissue containing nerve fibers and Schwann cells. In the peripheral area of the tumor, atypical chromaffin cells were also observed. Accumulation of eosinophilic serous fluid was also noted in the stromal tissue. There were neither...