Ectopic GHRH from neuroendocrine tumors causes acromegaly that may require lifelong monitoring | Research

The takeaway

Ectopic GHRH production by neuroendocrine tumors causes acromegaly indistinguishable from pituitary origin, with clues including pituitary hyperplasia on MRI, elevated serum GHRH, and potential for persistent growth after tumor resection.

Hyperplasia, not adenoma
Pituitary MRI showing hyperplasia rather than a discrete adenoma is a key clue that acromegaly is caused by ectopic GHRH from a neuroendocrine tumor

What the researchers found

Ectopic GHRH from NETs: clinically indistinguishable from pituitary acromegaly. Clues: pituitary hyperplasia (not adenoma), elevated serum GHRH, extra-pituitary tumor. Treatment: tumor resection + somatostatin analogs. Risk: persistent hyperplasia/adenoma from prolonged GHRH exposure. MEN1 testing recommended.

Why it matters

Misdiagnosing ectopic GHRH acromegaly as pituitary adenoma leads to unnecessary pituitary surgery. Recognizing the correct diagnosis enables targeted NET treatment and avoids surgical complications.

How the study worked

Narrative review of ectopic GHRH acromegaly diagnosis, management, and long-term follow-up.

What this study cannot tell us

Review of a rare condition—limited case numbers. Diagnostic algorithms not standardized. Long-term outcomes data sparse.

How to read the evidence

Narrative review of a rare condition. Good clinical guidance based on accumulated case experience.

When this study was published

Published in 2025.

The bigger picture

Understanding ectopic peptide hormone production is crucial for endocrinology. GHRH-secreting NETs exemplify how tumors can hijack normal peptide signaling pathways to cause systemic endocrine disease.

Questions still open

Should serum GHRH be routinely measured in new acromegaly cases?
How long after NET resection should IGF-1 monitoring continue?
Can pituitary adenomas from prolonged GHRH exposure regress after tumor removal?

Common questions

What is ectopic GHRH acromegaly?

Sometimes tumors outside the pituitary gland (usually neuroendocrine tumors) produce GHRH peptide, which stimulates the pituitary to release too much growth hormone—causing acromegaly. This is different from the usual cause (a pituitary tumor) and requires different treatment.

How is it different from regular acromegaly?

The symptoms are identical, but the treatment is very different. Instead of pituitary surgery, the extra-pituitary tumor must be found and removed. Clues include pituitary MRI showing diffuse enlargement (not a focused tumor) and elevated blood GHRH levels.

Read the original research

Ectopic GHRH production: revisiting a rare cause of acromegaly.

Reviews in endocrine & metabolic disorders, 26(4), 593-602

View on PubMed ↗Publisher’s paper ↗

Citation

Stumpf, Matheo A M; Santana, Nathalie Oliveira; Machado, Marcio Carlos; Duarte, Felipe H; Glezer, Andrea; Raverot, Gérald; Raverot, Véronique; Jallad, Raquel S. (2025). Ectopic GHRH production: revisiting a rare cause of acromegaly.. Reviews in endocrine & metabolic disorders, 26(4), 593-602. https://doi.org/10.1007/s11154-025-09961-w