Accepted on 01 Jun 2019
Submitted on 10 Feb 2019
A 38-year-old man with a hypervascular mass lesion in the pancreas (Figure 1A) detected on Computed Tomography (CT) was referred to our institution for a 68Ga DOTATATE PET/CT to identify metastatic disease. 68Ga DOTATATE is an imaging agent targeting somatostatin receptors (SSTR). 68Ga DOTATATE PET/CT is an established method in the work-up for neuroendocrine tumors (NETs), because SSTRs are over-expressed by the majority of well-differentiated NETs.
PET images showed a focus of uptake in the pancreas (Figures 1B and 2A, arrows) and moderate tracer uptake foci (arrows) in the spinous process of the first thoracic vertebra (Figures 2B and 3A), the bodies of the fifth and eighth thoracic vertebras (Figures 2C, 3B, and 3C), and the right iliac wing (Figures 2D and 3D). These uptakes of 68Ga DOTATATE could be taken for bone metastases. The corresponding CT images, however, showed characteristic appearances of hemangiomas, consisting in bone demineralization with vertical striation due to thickened trabeculae (“Corduroy sign” on the sagittal planes) and a “polka-dot” appearance on the axial slices where the thickened trabeculae are seen as small punctate areas of sclerosis (Figure 3, arrows).
There are few benign differential diagnoses for the accumulation of SSTR analogs. 68Ga DOTATATE can accumulate in benign inflammatory diseases as activated macrophages and lymphocytes express somatostatin receptors on their surface. The exact mechanism of uptake in these benign lesions is not clear and there are very little data for hemangiomas 1.
Although bone metastasis from NETs are very rare, without evaluation of the concurrent CT images, the vertebral tracer uptake could be interpreted as skeletal metastases. Combining the anatomic and metabolic information on PET/CT is crucial for accurate tumor staging.
The authors have no competing interests to declare.
Brogsitter, C, Hofmockel, T and Kotzerke, J. 68Ga DOTATATE Uptake in Vertebral Hemangioma. Clin Nucl Med. 2014; 39: 462–463. DOI: https://doi.org/10.1097/RLU.0000000000000282