Biochemical Recurrence of Prostate Cancer Presenting as Solitary Testicular Metastasis on 68Ga-Labeled Prostate-Specific Membrane Antigen Ligand Positron Emission Tomography/Computed Tomography.

Prostate adenocarcinoma (PCa) is the most frequently diagnosed malignancy in the male population, with the most common sites for secondary lesions being the lymph nodes, bones, and lungs. Testicular metastases from PCa are very rare and mostly identified incidentally after therapeutic orchiectomy for advanced PCa or during autopsy. Here we present a case involving a 64-year-old man with biochemical recurrence of castrated oligometastatic PCa that presented as solitary testicular metastasis on Ga-PSMA ligand positron emission tomography/computed tomography.

Assessment of biological and clinical aggressiveness of invasive ductal breast cancer using baseline 18F-FDG PET/CT-derived volumetric parameters.

OBJECTIVE: The aim of this study was to evaluate the relationship of baseline fluorine-18-fluorodeoxyglucose PET/computed tomography (CT)-derived volumetric parameters for the primary tumor with clinicopathological risk factors and molecular subtypes in patients with invasive ductal breast carcinoma (IDBC). PATIENTS AND METHODS: We evaluated 65 patients who underwent fluorine-18-fluorodeoxyglucose PET/CT for initial breast cancer staging. The association of maximum and mean standardized uptake values (SUVmax and SUVmean, respectively), metabolic tumor volume, and total lesion glycolysis (TLG) with clinicopathological risk factors and molecular subtypes was investigated and the discriminative power of significant features was assessed. RESULTS: All volumetric parameters were significantly higher for tumors measuring more than 2 cm and with a Ki-67 index of at least 20. Estrogen receptor (ER) and progesterone receptor (PR)-negative (ER-/PR-), human epidermal growth factor receptor 2-positive (HER2+), and triple-negative tumors showed increased SUVmax. SUVmax and SUVmean were higher for triple-negative and HER2+ IDBC than for ER+/HER2- IDBC. Metabolic tumor volume and TLG showed no differences among subtypes. All volumetric parameters correlated with the clinical tumor size and the Ki-67 index; these correlations differed among the different subtypes. Patients with systemic metastases showed significantly higher TLG. Receiver operating characteristic analysis showed that SUVmax had the highest discriminative power for the different subtypes, whereas TLG had a statistically significant discriminative power for systemic metastasis. CONCLUSION: SUVmax may appropriately reflect the immunohistochemical characteristics of IDBC, whereas TLG is associated with clinical risk factors and systemic metastasis. Our preliminary findings suggesting different relationships between volumetric parameters and the clinical tumor size and the Ki-67 index for different subtypes require further evaluation.

Ectopic Pelvic Kidney Mimicking Sacral Metastasis on Post-Therapy Iodine-131 Scan of a Thyroid Cancer Patient.

A 25-year-old woman had total thyroidectomy and iodine-131 ablation therapy for papillary thyroid carcinoma. Whole body imaging on the 7th day of therapeutic activity demonstrated radioiodine uptake in the remnant tissue and intense heterogeneous uptake at the sacral region prominently in the posterior image. Initial interpretation was suspicious for sacral metastasis. Technetium-99m-methylene diphosphonate bone scan demonstrated normal bone uptake and the absence of left kidney. On blood-pool phase of bone scan, the absence of left renal activity and an extra area of uptake in the sacral region suggestive of pelvic kidney were noticed. Magnetic resonance imaging scan confirmed the ectopic pelvic kidney overlying the sacrum.