Abstract
Primary presacral/precoccygeal neuroendocrine tumors (NETs) are extremely uncommon,
however, can present with widespread metastases. We herein report the imaging and
therapeutic perspectives in a 45-year-old female patient of presacral-precoccygeal
NET who presented with low back pain. Magnetic resonance imaging of the lumbosacral
spine showed a soft tissue mass in the presacral region extending into the S1–S2 neural
foramen, along with another soft tissue mass in the precoccygeal region. Incidentally,
multiple well-defined lobulated hyperintense lesions were detected in both lobes of
the liver. 18 F-FDG PET/CT (18 F-fluorodeoxyglucose positron emission tomography/computed tomography) demonstrated
tracer accumulation in the primary soft tissue masses in the presacral and precoccygeal
regions, while the liver lesions did not show significant tracer uptake. A CT-guided
biopsy of the presacral mass confirmed a well-differentiated NET, Grade III, with
a Ki-67 index of 20 to 22%. 68 Ga-DOTATATE PET/CT revealed somatostatin receptor expression in the presacral and
precoccygeal masses, as well as in the bilobar liver lesions. Due to the tumor's presentation
with widespread metastases, surgery was deemed inappropriate, and peptide receptor
radionuclide therapy was planned.
Keywords neuroendocrine tumors - presacral-precoccygeal grade III NET -
177 Lu-DOTATATE -
68 Ga-DOTATATE PET/CT -
18 F-FDG PET/CT - bilobar liver metastasis - peptide receptor radionuclide therapy (PRRT)
- PET/CT
