Serendipitous Detection of Testicular Seminoma on F-18 FDG Positron Tomography

18F-FDG PET/CT in a Patient With Epididymo-Testicular Malacoplakia

ABSTRACT

A 56-year-old man presented with a 2-month history of a mass in the right epididymo-testicular region, which exhibited heterogeneous high avidity for 18F-FDG on PET/CT. Malignant tumor was highly suspected, leading to subsequent right orchiectomy and epididymectomy. Histopathological examination revealed the presence of characteristic Michaelis-Gutmann bodies within von Hansemann macrophages, confirming the diagnosis of malacoplakia.

68 GA-FAPI-04 PET/CT Versus 18 F-FDG PET/CT in Imaging of Malignant Mixed Germ Cell Testicular Tumor

ABSTRACT

18 F-FDG PET/CT imaging was performed for restaging in in a 16-year-old boy who was operated on for right testicular tumor and was diagnosed with malignant mixed germ cell tumor. Mild FDG uptake was observed in 2 nodules in both lungs and retroperitoneal lymph node in the abdomen. 68 Ga-FAPI (fibroblast activation protein inhibitor) 04 PET/CT showed moderate uptake of FAPI in lung nodules and retroperitoneal lymph node. In this case, 68 Ga-FAPI-04 PET/CT was shown to be superior to 18 F-FDG PET/CT in the evaluation of malignant mixed germ cell testicular tumor metastases.

Unexpected detection of melanoma brain metastasis by PET with iodine-124 betaCIT

To study the potential impact of iodine-124-beta-carbomethoxy-3beta(4-iodophenyl)tropane (I-124 betaCIT) in Parkinson disease, a I-124 betaCIT-PET scan was performed in 30-year-old man with suspected early Parkinson disease. The scan showed normal striatum uptake together with a focal spot in the left parietal cortex. The subsequent magnetic resonance imaging of the brain revealed a corresponding nodular lesion, presumably representing a metastasis. After clinical and diagnostic evaluation, a malignant metastatic melanoma was discovered. betaCIT is a cocaine derivative with a high affinity for dopamine and serotonin transporters mainly used to image the density of the dopamine reuptake transporter. In fact the role of I-123 betaCIT is typically represented by Parkinsonian syndromes of uncertain classification. The iodine-124 betaCIT uptake is a marker of dopamine transporters density, and the presence of focal uptake corresponding to a lesion on magnetic resonance images suggests a specific binding in this case of melanoma brain metastasis.