%0 Journal Article %A Harleen Kaur %A Isis Gayed %A Fathima Fijula Palot Manzil %T Evaluation of metastatic Hyalinizing clear cell carcinoma of the lung with F-18 FDG PET-CT: A rare lung primary metastatic to trapezius and paraspinal muscles %D 2021 %J Journal of Nuclear Medicine %P 2040-2040 %V 62 %N supplement 1 %X 2040Introduction: We present a rare case of primary hyalinizing clear cell carcinoma (HCCC) of the lung which showed FDG avid metastatic lesions in the muscle and lymph nodes on PET scan not obviously seen on the anatomic imaging. Materials and Method: Review of electronic medical record and institutional PACS Case Report: A 60 year old former smoker African American female presented with left lung abnormality on chest radiograph. Further work up with CT chest revealed a left upper lobe mass which turned out to be a squamous cell carcinoma on initial core biopsy. Subsequently patient underwent left upper lobectomy and postoperative biopsy revealed infiltrative tumor with morphology and molecular rearrangement keeping with diagnosis of HCCC. Patient was on yearly surveillance with chest Computerized Tomograms (CT). New bilateral lung nodules concerning for metastases were detected on CT scan five years after tumor resection. No other suspicious lesions were seen on the CT scans. F-18 FDG PET-CT was obtained was obtained to evaluate the extent of disease in the remainder of the body. Other metastatic lesions were seen including right supraclavicular lymph node and focal lesion in the right trapezius muscle. Right trapezius muscle lesion was biopsied and results were consistent with metastatic HCCC. Patient was started on chemotherapy with carboplatin and paclitaxel. 4 month follow up PET-CT showed progression with new metastasis in the left paraspinal muscle. There was also increase in size and metabolic activity of known right supraclavicular lymph node and right trapezius muscle metastases. Conclusion: To our knowledge there are no previously reported cases of primary hyalinizing clear cell carcinoma of the lung followed up with F-18 FDG PET-CT. Hypermetabolic muscular and small lymph nodal metastases detected on PET scan were not appreciated on anatomic imaging. Given the intense metabolic activity of the metastatic lesions in our case, it would be beneficial to include F-18 FDG PET-CT in the diagnosis and follow up of these patients. %U