FDG-PET/CT findings of a metastatic pituitary tumor

Abstract

The authors report the fluorodeoxyglucose (FDG)-positron emission tomography(PET)/computed tomography (CT) findings of a rare case of growth hormone-secreting pituitary carcinoma with multiple metastatic lesions to the skeleton. A 31-year-old male had presented with acromegaly and had received transsphenoidal resection of a pituitary tumor and adjuvant radiotherapy. However, the tumor recurred with local invasions and the patient underwent more resections and adjuvant chemotherapy. Several months later, the patient developed rising levels of insulin-like growth factor 1 and whole-body FDG-PET/CT scanning revealed multiple hypermetabolic lesions throughout the skeleton compatible with metastasis.

Figure 1

(A) T1-weighted MR imaging (spin echo, repetition time (TR)/echo time (TE)=466.7 ms/13 ms) with contrast enhancement of the head shows an enhancing mass in the sella turcica extending to the right cavernous sinus, consistent with local recurrence of tumor. (B) Whole-body FDG-PET/CT fusion image in the same level shows abnormal increased FDG uptake of tumor (large arrow) and physiological uptake of right temporal lobe (small arrow).

Figure 2

(A) Whole-body FDG-PET/CT fusion image shows an area of increased FDG uptake in the left sacral ala, consistent with metastatic tumor. (B) The T2-weighted MR imaging (fast-spin echo, TR/TE/echo train length=5200 ms/72 ms/17) with fat saturation shows increased T2 signal intensity in the same area.

Figure 3

PET/CT maximum intensity projection image showing numerous foci of increased tracer uptake in the cervical, thoracic, lumbar spine, and sternum, consistent with metastatic disease.