Ectopic acromegaly due to a pancreatic neuroendocrine tumor producing growth hormone-releasing hormone.
OBJECTIVE
To present a case of acromegaly due to ectopic growth hormone-releasing hormone (GHRH) secretion from a pancreatic neuroendocrine tumor in the context of multiple endocrine neoplasia type 1 (MEN 1).


METHODS
We describe the clinical, imaging, and pathologic findings of the study patient.


RESULTS
A 46-year-old woman presented with clinical and biochemical findings diagnostic of acromegaly. Magnetic resonance imaging showed a 1.2-cm sellar mass. Following resection of the macroadenoma, serum insulin-like growth factor 1 (IGF-1) and growth hormone (GH) levels remained unchanged. Pathologic examination revealed adenomatous changes, including a nonsecretory focus and a prolactin immunopositive area (GH stain negative in both). Octreotide long-acting release was ineffective. Search for an ectopic tumor included normal octreoscan and abdominal computed tomography. GHRH was greater than 1000 pg/mL. Repeated abdominal computed tomography documented a 6.2-cm mass in the tail and body of the pancreas. Distal pancreatectomy revealed a pancreatic neuroendocrine tumor that stained positive for GHRH. Postoperatively, serum GHRH and IGF-1 normalized. Re-evaluation of the initial pituitary pathologic specimen revealed additional somatotroph hyperplasia of the adjacent, normal pituitary gland. Primary hyperparathyroidism was diagnosed, and multigland parathyroid hyperplasia was noted at surgery. Genetic testing was positive for a mutation in the MEN1 gene.


CONCLUSIONS
This patient's acromegaly was resistant to somatostatin analogue therapy, reflecting the negative octreoscan imaging. In addition, this case is novel because the patient presented with pituitary adenomatous changes, which were presumably associated with MEN 1 and/or possibly the elevated GHRH levels.
Weiss
Danielle E
DE
Department of Medicine, Stanford University School of Medicine, Stanford, California, USA.
Vogel
Hannes
H
Lopes
M Beatriz S
MB
Chang
Steven D
SD
Katznelson
Laurence
L
D000172:Acromegaly / Q000097:blood / Q000209:etiology* / Q000378:metabolism; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000378:metabolism*; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000097:blood / Q000150:complications* / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000097:blood / Q000150:complications* / Q000378:metabolism*
D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D013007:Growth Hormone-Releasing Hormone