Incidental detection of elastofibroma dorsi on PET-CT: initial findings and changes in tumor size and standardized uptake value on serial scans.
OBJECTIVE
We describe changes in elastofibroma dorsi (EFD) as observed in serial fluorine-18 fluorodeoxyglucose (F-FDG) PET-computed tomography (CT) imaging studies.


METHODS
F-FDG PET-CT studies carried out between January 2006 and January 2015 at a single institution were reviewed by an experienced radiologist and nuclear medicine specialist. When available, previous or subsequent imaging studies were reviewed to evaluate changes in EFD.


RESULTS
Of 28 500 PET-CT studies carried out, EFD was identified in 68 from 20 patients (mean age 67.1±10.2 years; 14 women). Five patients had unilateral lesions and 15 patients had bilateral lesions. Eighteen patients had oncologic diseases. The mean size of EFD at first presentation was 13.95±5.90 mm and the mean homogeneous low-grade F-FDG uptake was maximum standardized uptake value (SUVmax) 2.24±0.95. One or more additional CT scans were performed in 17 patients; the mean interval between the first and last scans was 57.4±39.2 months. EFD was unchanged in size in 7/17 (41%) and showed slow growth in 10/17, reaching a mean size of 19 mm. The mean monthly growth rate was 0.1±0.10 mm. PET imaging in 11 patients showed a mean first SUVmax of 2.08±1.17 and a mean last SUVmax of 2.74±1.05 after a mean of 47.5±31.5 months (P=0.63).


CONCLUSIONS
Serial PET-CT studies may show a stable or slowly enlarging mass on a CT scan without changes in F-FDG uptake on PET imaging. Familiarity with CT appearances and F-FDG uptake of EFD are important for correct interpretation of F-FDG PET-CT studies.
Departments of aNuclear Medicine bDiagnostic Imaging cRadiation Oncology, Chaim Sheba Medical Center, Tel Hashomer dSackler School of Medicine, Tel Aviv University, Ramat Aviv eDivision of Surgery, Assaf Harofeh Medical Center, Zerifin, Israel fInstitute of Nuclear Medicine, University College London and UCL Hospitals, London, UK.
Tima
T
Davidson
Elinor
E
Goshen
Iris
I
Eshed
Jeffrey
J
Goldstein
Bar
B
Chikman
Simona
S
Ben-Haim
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D033162:Incidental Findings; D008297:Male; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012540:Scapula / Q000000981:diagnostic imaging / Q000378:metabolism; D012680:Sensitivity and Specificity; D012983:Soft Tissue Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D047368:Tumor Burden
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18