Endocrinol Metab.  2010 Dec;25(4):321-325. 10.3803/EnM.2010.25.4.321.

Clinical Characteristics of 16 Patients with Pituitary Tumor Incidentally Detected by 18F-Fluorodeoxyglucose PET-CT (18F-FDG PET-CT)

• Kim HJ
• Cheon GJ
• Cho AR
• Lee CH
• Youn SM
• Ahn SJ
• Jang SE
• Kim JM
• Lee YY
• Yi KH

• KMID: 1497758
• DOI: http://doi.org/10.3803/EnM.2010.25.4.321

Abstract

BACKGROUND
It is uncommon to unexpectedly discover pituitary tumor as a hypermetabolic lesion on an 18F-FDG PET-CT scan for the evaluation of an unrelated disease when the patient does not show neurological or endocrine signs and symptoms.
METHODS
We retrospectively analyzed the medical records of 16 patients with pituitary tumor that was detected incidentally on 18FFDG PET-CT at the Korea Cancer Center Hospital from January 2002 to September 2009. We analyzed their clinical features in detail.
RESULTS
On 35,505 18F-FDG PET-CT scans, 16 (0.045%) patients were diagnosed with pituitary incidentaloma. They underwent 18FFDG PET-CT for the evaluation of the state of malignancy. All of them had no signs and symptoms related to pituitary tumor. The average age of the patients was 63.3 +/- 12.0 years (49-85 years). Eleven patients were men and 5 were women. The mean diameter of the tumor was 17.9 +/- 5.7 mm. Most of the pituitary incidentalomas were macroadenoma. The result of tumor morphologic evaluation by the Hardy classification was as follows: 6 grade IV, 1 grade III, 3 grade II and 1 grade I. The mean standardized uptake value of the tumor was 10.6 +/- 6.7. Ten patients had endocrine evaluation and they showed a normal hormone level. Among 16 patients, 4 patients received TSA and they were diagnosed with pituitary adenoma.
CONCLUSION
This study showed that pituitary incidentaloma discovered on 18F-FDG PET-CT was extremely rare. It was almost all non-functioning macroadenoma and this showed relatively high FDG uptake.

Keyword

18F-FDG PET-CT; Incidental discovery; Pituitary tumor

MeSH Terms

Female
Fluorodeoxyglucose F18
Humans
Incidental Findings
Korea
Male
Medical Records
Pituitary Neoplasms
Retrospective Studies
Fluorodeoxyglucose F18

Figure

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  Fig. 1 Midline sagittal section (A) and coronal section (B) of 18FDG-PET. Focal FDG uptake at the pituitary gland (arrow).

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  Fig. 2 Midline sagittal (A) and coronal (B) image of gadolinium-enhanced T1 weighted MRI. 19 × 17 × 15 mm heterogeneously enhanced mass involving pituitary gland (arrow).

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  Fig. 3 Graph shows the relationship between the pituitary tumor size and SUV. (Correlation coefficient r = 0.809, P < 0.01) SUV, standardized uptake value.

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