Spherical type of amyloidogenic pituitary prolactinoma in a 50 year old male

Prolactinomas are the most common pituitary tumors and are treated with surgery with or without dopamine agonists. Amyloid in prolactinoma is known to occur, but spherical type of amyloid deposition is extremely rare and can pose a diagnostic challenge during intraoperative consultation. They do not respond to medical treatment with dopamine agonists and enlarge in size or undergo fibrosis, causing a failure of medical therapy. Hence, it needs to be identified preoperatively by imaging to institute appropriate management. Here we report a case of a 50 year male with symptoms of burning sensations in the left upper limb and temporal seizures for 4 months. Magnetic resonance imaging showed a well-defined lobulated lesion measuring 4x3.5x3cm eroding the floor of sella. Histology showed spherical, eosinophilic amyloid material with focal cellular areas. Immunohistochemistry and serum levels were high for prolactin. 11 months later, the patient was readmitted with CSF rhinorrhea. The biopsy revealed abundant spherical amyloid with scant cellularity suggesting a recurrence.