It is related to high levels of growth hormone (GH) and insulin-like growth factor-I (IGF-1).

MRI

The enhancement was significantly lower in GH secreting pituitary neuroendocrine tumor than in non-secreting ones. 1).

T2 weighted image differentiates GH secreting pituitary neuroendocrine tumors into subgroups with particular behaviors. This raises the question of whether T2-weighted signal could represent a factor in the classification of acromegaly in future studies 2).

In patients with acromegaly, T2 weighted image signal intensity at diagnosis correlates with histological features and predicts biochemical outcome of first-line somatostatin analogues (SA) treatment 3).

Biomarkers

Each of the biomarkers, Ki-67 and p53, along with patient's age and mixed GH-prolactin secretion showed a kind of correlation with each of aspects of the clinical, hormonal and radiologic outcome of GH-secreting pituitary neuroendocrine tumors 4).

Best Practices

D1-rGH could be a highly specific test for the early diagnosis of long-term acromegaly persistence, which is predicted by a value > 2.5 ng/mL with a great degree of certainty. The diagnostic performance of D2-rGH was insufficient. Further research is required to validate these preliminary results prior to modifying the postoperative management of acromegaly 5).

1)
Lundin P, Bergström K. Gd-DTPA-enhanced MR imaging of pituitary macroadenomas. Acta Radiol. 1992 Jul;33(4):323-32. PubMed PMID: 1633042.
2)
Potorac I, Petrossians P, Daly AF, Schillo F, Ben Slama C, Nagi S, Sahnoun Fathallah M, Brue T, Girard N, Chanson P, Nasser G, Caron P, Bonneville F, Ravérot G, Lapras V, Cotton F, Delemer B, Higel B, Boulin A, Gaillard S, Luca F, Goichot B, Dietemann J, Beckers A, Bonneville J. Pituitary MRI characteristics in 297 acromegaly patients based on T2-weighted sequences. Endocr Relat Cancer. 2015 Jan 2. pii: ERC-14-0305. [Epub ahead of print] PubMed PMID: 25556181.
3)
Heck A, Ringstad G, Fougner SL, Casar-Borota O, Nome T, Ramm-Pettersen J, Bollerslev J. Intensity of pituitary neuroendocrine tumor on T2-weighted magnetic resonance imaging predicts the response to octreotide treatment in newly diagnosed acromegaly. Clin Endocrinol (Oxf). 2012 Jul;77(1):72-8. doi: 10.1111/j.1365-2265.2011.04286.x. PubMed PMID: 22066905.
4)
Alimohamadi M, Ownagh V, Mahouzi L, Ostovar A, Abbassioun K, Amirjmshidi A. The impact of immunohistochemical markers of Ki-67 and p53 on the long-term outcome of growth hormone-secreting pituitary neuroendocrine tumors: A cohort study. Asian J Neurosurg. 2014 Jul-Sep;9(3):130-6. doi: 10.4103/1793-5482.142732. PubMed PMID: 25685203; PubMed Central PMCID: PMC4323896.
5)
Cambria V, Beccuti G, Prencipe N, Penner F, Gasco V, Gatti F, Romanisio M, Caputo M, Ghigo E, Zenga F, Grottoli S. First but not second postoperative day growth hormone assessments as early predictive tests for long-term acromegaly persistence. J Endocrinol Invest. 2021 Apr 10. doi: 10.1007/s40618-021-01553-0. Epub ahead of print. PMID: 33837920.