Incidental prostate-specific membrane antigen-avid glioblastoma detected on 68Ga-prostate-specific membrane antigen PET/CT.

A 74-year-old man was referred for a 68Ga-prostate-specific membrane antigen (PSMA) PET/CT scan for newly diagnosed prostate cancer which confirmed the presence of PSMA avid cancer in the right gland with no evidence of PSMA metastasis. Incidentally, there was a markedly PSMA avid (SUVmax 7.0) lobulated periventricular mass in the region of the left basal ganglia which was T2 hyperintense and T1 hypointense with perilesional oedema and vivid Gadolinium enhancement on MRI. The patient underwent stereotactic guided biopsy which confirmed LHD wild-type glioblastoma (WHO grade IV).

A rare case of urachal mucinous adenocarcinoma detected by 18F-FDG PET/CT and MRI.

Urachal adenocarcinomas are rare cancers of the urinary bladder. Both CT and MRI are useful imaging modalities for the diagnosis and evaluation of urachal adenocarcinoma. Unlike CT or MR, there have been variable FDG PET findings with urachal tumours potentially due to considerable variation in their hypermetabolism. We present the case of a 24 year-old female patient who was diagnosed with urachal mucinous adenocarcinoma with characteristic features on CT and MRI which also exhibit moderately increased FDG avidity.

Incidental Intrahepatic Hepatocellular Cholangiocarcinoma Detected on 68Ga-PSMA PET/CT.

ABSTRACT: A 69-year-old man with intermediate-risk prostate cancer and a mildly elevated prostate-specific antigen of 8.2 µg/L was referred for 68Ga-prostate-specific membrane antigen (68Ga-PSMA) PET/CT for primary staging. An incidental intensely 68Ga-PSMA-avid hepatic focus was seen on PSMA PET and subsequent FDG PET/CT and MRI cholangiogram. This was confirmed to be hepatocellular cholangiocarcinoma on subsequent histopathological examination.

Steroid responsive inflammatory myofibroblastic tumor of the lung evaluated by FDG PET/CT imaging.

A 68-year-old gentleman was referred for 18F-FDG PET/CT for a pulmonary mass in the left upper lobe which demonstrated intensely FDG-avid confluent pulmonary consolidation in the left upper lobe (SUVmax 15.1). Histopathologic biopsy of the left upper lobe lung mass was consistent with inflammatory myofibroblastic tumor (IMT). The patient was started on steroid treatment in conjunction with antibiotics. Follow-up FDG PET/CT 3 weeks after commence of treatment showed remarkable response of the IMTs to therapy with much less avid FDG uptake (SUVmax 5.4) and marked improvement in the pulmonary consolidation. Nevertheless, the patient underwent left upper lobe lobectomy due to evidence of persistent cystic disease and malignant potential associated with IMTs. Final histopathology was consistent with IMT with no evidence of malignancy.

Synchronous Recurrence of Metachronous Lung Cancer and Hodgkin Lymphoma Within an Axillary Lymph Node Isolated on 18F-FDG PET/CT.

ABSTRACT: An 82-year-old man with a background of non-Hodgkin lymphoma in remission, resected left lower lobe adenocarcinoma (stage IA), and resected cutaneous melanoma of the left forearm more than 5 years prior presented with cerebral metastatic disease. Excision biopsy confirmed adenocarcinoma of lung origin. Further evaluation with 18F-FDG PET/CT demonstrated FDG-avid disease in the right thorax, axilla, and lower neck and isolated cutaneous uptake in the right forearm. Lymph node biopsy confirmed synchronous mantle cell lymphoma and metastatic adenocarcinoma of the lung.

Solitary 18F-fluorodeoxyglucose avid spinous process cholangiocarcinoma metastasis proven on CT guided percutaneous needle bone biopsy.

A 65-year-old female with newly diagnosed cholangiocarcinoma was referred for a FDG PET/CT for initial staging. There was a region of moderate FDG avidity localizing to the hepatic hilum representing the primary site of malignancy. An unexpected moderately FDG avid focus was demonstrated in the spinous process of the T11 vertebra with no corresponding mass lesion seen on low dose CT and no evidence of distant metastatic disease elsewhere. A percutaneous CT guided needle bone biopsy was performed which confirmed a solitary T11 spinous process metastasis on histopathology.

Atypical metastatic lung cancer of the right ventricle on FDG PET/CT.

Although primary cardiac tumours are extremely uncommon, secondary tumours or cardiac metastasis are not. We present a 68-year-old gentleman with squamous cell carcinoma of the right lower lobe with bony metastasis to the right clavicle who was treated with radiotherapy to the lung and clavicle as well as combination immunotherapy (Pembrolizumab) and chemotherapy (Carboplatin/Paclitaxel). Despite completing the above treatment regime, 18F-FDG PET/CT scan showed progression with two new sites of metastasis including a focus in the lateral wall of the right ventricle which correlate to a soft tissue density mass on CT as well as a FDG avid mass in the left masseter. Identification of cardiac lesions with 18F-FDG PET/CT maybe challenging with routine preparation due high physiological FDG uptake in the myocardium and significant variability, nevertheless, focal FDG uptake in the heart should be carefully assessed for the possibility of cardiac metastasis.

Incidental prostate-specific membrane antigen-avid meningioma detected on 68Ga-prostate-specific membrane antigen PET/CT.

A 70-year-old gentleman with a history of Gleason score 7 (3 + 4) prostate adenocarcinoma was treated with radical prostatectomy with clear surgical margins. Postoperatively his prostate specific antigen was undetectable. However, his prostate specific antigen was slowly rising and he was referred for a 68Galium-Prostate Specific Membrane Antigen (PSMA) PET/CT scan. Findings were suggestive of local prostatic cancer recurrence with no evidence of nodal or distant metastasis. An incidental PSMA avid focus was noted in the left frontal lobe, inseparable from the left frontal bone laterally. Subsequent MRI findings were consistent with meningioma. Meningioma is the most common primary brain tumor and may be a cause of false positive prostate cancer metastasis due to 68Ga-PSMA uptake.

Variability of Central Corneal Thickness Measurements-Comparing Zeiss IOL Master and Tomey Corneal Specular Microscope.

PURPOSE: The aim of this study was to compare the intraobserver repeatability and agreement of central corneal thickness (CCT) measurements by 2 commonly available instruments, Zeiss IOL Master 700 (SS-OCT-based optical biometry device) and Tomey corneal specular microscope EM-3000 (Noncontact specular microscopy). DESIGN: Retrospective study. METHODS: This is a retrospective analysis of data from routine clinical practice in which preoperative CCT measurements of 105 patients scheduled for cataract surgery were analyzed. Two consecutive CCT measurements were measured using Zeiss IOL Master 700 and Tomey corneal specular microscope EM-3000 by the same examiner. The repeatability of CCT measurements was analyzed by mean intraobserver difference, coefficient of repeatability (CR), and intraclass correlation. The agreement between the 2 methods was analyzed by mean difference and limits of agreement (LoA) using the Bland-Altman method. RESULTS: The mean absolute intraobserver difference between the 2 measurements by Zeiss and Tomey were 3.41 ±â€Š3.98 µm and 8.62 ±â€Š9.52 µm (P < 0.0001), respectively. For Zeiss, the CR was 10.3 µm with 95% LoA of -10.5 to 10.1 µm. For Tomey, the CR was 25.2 µm with 95% LoA of -25.2 to 25.2 µm. The mean CCT measurements ±â€Šstandard deviation by Zeiss and Tomey were 544.0 ±â€Š38.1 µm and 532.6 ±â€Š40.0 µm, respectively (P = 0.003). The 95% LoA in CCT between the 2 methods was -15.8 to 38.7 µm. CONCLUSIONS: Zeiss IOL Master 700 has superior intraobserver repeatability and consistency than Tomey EM-3000. Zeiss produced higher CCT measurements than Tomey; hence, in clinical practice, interchangeability between these 2 methods is limited.