Belated Diagnosis of Hashimoto's Disease

Abstract

<b>978</b> <h3><b>Objectives:</b></h3> 1. To recognize patterns of uptake in different ganglia which may mimic lymph node metastases in different anatomic locations 2. To understand the role of CT characterization and localization in the differentiation of benign uptake in ganglia versus metastatic lymph nodes. 3. How to interpret these findings and direct further evaluation or recommendation if needed. <b>Abstract:</b> Several recent studies revealed accurate staging of primary prostate cancer (PC) and restaging after biochemical recurrence with ⁶⁸Ga -PSMA PET/CT. However, ⁶⁸Ga -PSMA uptake is not completely specific to PC. Recent study showed relatively high PSMA uptake in coeliac ganglia in most patients which may mimic lymph node metastases in this area in PC patients undergoing ⁶⁸Ga -PSMA PET/CT examination for staging or restaging¹. We will demonstrate in a large collection of cases varieties of findings with different patterns of PSMA uptake which would include unilateral and bilateral uptake, mild and moderate uptake, focal and diffuse uptake, isolated ganglion uptake and multiple ganglia uptake in same patient. Also, correct and careful of interpretation of the CT scan as part of the ⁶⁸Ga-PSMA PET/CT examination is of special importance in differentiating PSMA uptake in a ganglia versus in lymph nodes. Associated CT findings and characterization of ganglia in the ⁶⁸Ga-PSMA PET/CT would be demonstrated at different location including stellate ganglia in the cervicothoracic region, coeliac and superior mesenteric in the abdomen and inferior mesenteric in the pelvic region. We will also show the appearance of some of these findings by other imaging modalities for further characterization. Reading physician should be aware of the frequently encountered physiologic uptake of 68Ga-labelled PSMA ligand in different ganglia in order to avoid false positive interpretation.