Vol 68, No 3 (2017)
Case report
Published online: 2017-06-21

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All that glitters on PET is not cancer! 18F-deoxy-glucose avidity versus tumor biology: pituitary incidentaloma in a survivor of two previous unrelated malignancies

Dragana Miljić12, Emilija Manojlović-Gačić3, Milica Skender-Gazibara3, Toplica Milojević4, Vojislav Bogosavljević4, Nebojša Kozarević25, Nebojša Petrović, Marko Stojanović12, Sandra Pekić12, Mirjana Doknić12, Milan Petakov12, Vera Popović2
Pubmed: 28660992
Endokrynol Pol 2017;68(3):352-359.


Introduction: 18F-deoxy-glucose positron emission tomography combined with computed tomography (18F-FDG PET/CT) is routinely used in the detection of malignant disease based on the property of malignant cells to fuel their growth and replication by increased glucose uptake. Malignant lesions are rare in the sellar region, while pituitary adenomas are the most common pathology. These are benign neoplasms with insidious onset and low proliferation activity, and therefore are only exceptionally detected by 18F-FDG PET/CT. Studies that compare the biology of pituitary adenomas and their radiological properties using PET/CT are still lacking.

Case report: We investigate and discuss tumour biology in light of increased 18F-FDG avidity in a symptom-free, 70-year-old male patient, previously treated for two different malignancies (lung and rectal). Increased tracer accumulation in the sellar region was incidentally detected on a follow-up 18F-FDG PET/CT scan. Additional MRI disclosed pituitary adenoma. Normal hormonal status was found, consistent with the diagnosis of non-functioning pituitary adenoma. Analysis of tumour tissue after pituitary surgery confirmed a silent gonadotroph adenoma with low proliferation index. Low expression of oncogene-induced senescence markers did not support senescence as the explanation for the tumour’s low proliferative activity although it was in consonance with the hormonal activity.

Conclusions: Pituitary adenomas can manifest as hypermetabolic foci on 18F-FDG PET/CT imaging with increased tracer uptake even in indolent, clinically silent pituitary adenomas with low mitotic activity. Special attention should be paid to evaluation of 18F-FDG avid pituitary adenomas in patients with multiple malignancies, bearing in mind that avidity does not always mirror its biological behaviour.


  1. Campeau RJ, David O, Dowling AM. Pituitary adenoma detected on FDG positron emission tomography in a patient with mucosa-associated lymphoid tissue lymphoma. Clin Nucl Med. 2003; 28(4): 296–298.
  2. Koo CW, Bhargava P, Rajagopalan V, et al. Incidental detection of clinically occult pituitary adenoma on whole-body FDG PET imaging. Clin Nucl Med. 2006; 31(1): 42–43.
  3. Maffei P, Marzola MC, Musto A, et al. A very rare case of nonfunctioning pituitary adenoma incidentally disclosed at 18F-FDG PET/CT. Clin Nucl Med. 2012; 37(5): e100–e101.
  4. Joshi P, Lele V, Gandhi R. Incidental detection of clinically occult follicle stimulating hormone secreting pituitary adenoma on whole body 18-Fluorodeoxyglucose positron emission tomography-computed tomography. Indian J Nucl Med. 2011; 26(1): 34–35.
  5. Gemmel F, Balink H, Collins J, et al. Occult prolactinoma diagnosed by FDG PET/CT. Clin Nucl Med. 2010; 35(4): 269–270.
  6. Ryu SI, Tafti BA, Skirboll SL. Pituitary adenomas can appear as hypermetabolic lesions in (18) F-FDG PET imaging. J Neuroimaging. 2010; 20(4): 393–396.
  7. Maiza JC, Zunic P, Revel C, et al. Acromegaly revealed by 18FDG-PET/CT in a plasmocytoma patient. Pituitary. 2012; 15(4): 614–615.
  8. Karapolat I, Oncel G, Kumanlıoğlu K. Clinically Occult Pituitary Adenoma Can Appear as a Hypermetabolic Lesion on Whole Body FDG PET Imaging in a Patient with Lymphoma. Mol Imaging Radionucl Ther. 2013; 22(1): 18–20.
  9. Jeong SY, Lee SW, Lee HJ, et al. Incidental pituitary uptake on whole-body 18F-FDG PET/CT: a multicentre study. Eur J Nucl Med Mol Imaging. 2010; 37(12): 2334–2343.
  10. Hyun SH, Choi JY, Lee KH, et al. Incidental focal 18F-FDG uptake in the pituitary gland: clinical significance and differential diagnostic criteria. J Nucl Med. 2011; 52(4): 547–550.
  11. Famini P, Maya MM, Melmed S. Pituitary magnetic resonance imaging for sellar and parasellar masses: ten-year experience in 2598 patients. J Clin Endocrinol Metab. 2011; 96(6): 1633–1641.
  12. Agarwal KK, Sharma P, Singla S, et al. A rare case of non-small cell lung cancer metastasizing to the pituitary gland: detection with (18)F-FDG PET-CT. Clin Nucl Med. 2014; 39(5): e318–e319.
  13. Malhotra G, Asopa RV, Sridhar E. Unusual case of isolated parasellar metastasis from carcinoma of thyroid. Clin Nucl Med. 2013; 38(2): 145–148.
  14. Akkas BE, Vural GU. The incidence of secondary central nervous system involvement in patients with non-Hodgkin's lymphoma as detected by 18F-FDG PET/CT. Nucl Med Commun. 2013; 34(1): 50–56.
  15. Soussan M, Wartski M, Ezra J, et al. Non-Hodgkin lymphoma localization in the pituitary gland: diagnosis by FDG-PET/CT. Clin Nucl Med. 2008; 33(2): 111–112.
  16. Ilkhchoui Y, Appelbaum DE, Pu Y. FDG-PET/CT findings of a metastatic pituitary tumor. Cancer Imaging. 2010; 10: 114–116.
  17. van der Hiel B, Blank CU, Haanen JB, et al. Detection of early onset of hypophysitis by (18)F-FDG PET-CT in a patient with advanced stage melanoma treated with ipilimumab. Clin Nucl Med. 2013; 38(4): e182–e184.
  18. Molitch ME. Pituitary tumors: pituitary incidentalomas. Best Pract Clin Endocrinol Metab 2009; 23: 667-75.
  19. Koppelmans V, Schagen SB, Poels MMF, et al. Incidental findings on brain Magnetic Resonance Imaging in long-term survivors of breast cancer treated with adjuvant chemotherapy. Eur J Cancer. 2011; 47(17): 2531–2536.
  20. Popovic V, Damjanovic S, Micic D, et al. Increased incidence of neoplasia in patients with pituitary adenomas. The Pituitary Study Group. Clin Endocrinol (Oxf). 1998; 49(4): 441–445.
  21. Feng Z, He D, Mao Z, et al. Utility of 11C-Methionine and 18F-FDG PET/CT in Patients With Functioning Pituitary Adenomas. Clin Nucl Med. 2016; 41(3): e130–e134.
  22. Manojlovic-Gacic E, Skender-Gazibara M, Popovic V, et al. Oncogene-Induced Senescence in Pituitary Adenomas--an Immunohistochemical Study. Endocr Pathol. 2016; 27(1): 1–11.
  23. Alexandraki KI, Munayem Khan M, Chahal HS, et al. Oncogene-induced senescence in pituitary adenomas and carcinomas. Hormones (Athens). 2012; 11(3): 297–307.
  24. Losa M, Mortini P, Barzaghi R, et al. Early results of surgery in patients with nonfunctioning pituitary adenoma and analysis of the risk of tumor recurrence. J Neurosurg. 2008; 108(3): 525–532.