In the study of early oral cavity tumors, ultrasound is accurate for demonstrating the level of tumor infiltration and contributes to the therapeutic choice.

Objectives. To assess the potential of CT for characterizing small renal tumors. Methods. 76 patients with <4 cm renal tumors underwent CT examination. The following parameters were assessed: presence of calcifications, densitometry on unenhanced and enhanced scans, washout percentage, urinary tract infiltration, star-shaped scar, and paradoxical effect. Results. Calcifications were found in 7/56 (12.5%) carcinomas. Clear cell carcinomas were as follows: mean density 183.5 HU (arterial phase), 136 HU (portal phase), and 94 HU (delayed phase), washout 34.3%; chromophobe carcinomas were as follows: mean density 135 HU (arterial phase), 161 HU (portal phase), and 148 HU (delayed phase), washout 28%; papillary carcinomas were as follows: mean density 50.3 HU (arterial phase), 60 HU (portal phase), and 58.1 HU (delayed phase), washout 2.7%. In 2/56 (3.6%) cases urinary tract infiltration was found. Oncocytomas were as follows: mean density 126.5 HU (arterial phase), 147.5 HU (portal phase), and 115.5 HU (delayed phase), washout 28.6%. On unenhanced scans, angiomyolipomas were as follows: density values <30 HU in 12/12 (100%) of cases and on enhanced scans: mean density 78 HU (arterial phase), 128 HU (portal phase), and 80 HU (delayed phase), washout 50%. Conclusions. Intralesional calcifications and urinary tract infiltration are suggestive for malignancy, with the evidence of adipose tissue for angiomyolipomas and a modest increase in density with a reduced washout for papillary carcinomas. The intralesional density on enhanced scans, peak enhancement, and washout do not seem significant for differentiating clear cell, chromophobe carcinomas, angiomyolipomas, and oncocytomas.

Background We present the clinical, MRI and CT findings in a case of a new mitochondrial genome mutation (tRNA arginine gene), characterized by brain calcifications which are indicative of Kearns–Sayre syndrome (KSS). Some radiological features resembled those of Fahr’s disease (affecting the PDGFRB gene). Case presentation A 36-year-old male presented some typical clinical features of KSS, including onset before 20 years of age, pigmentary retinopathy, progressive external ophthalmoplegia and ptosis. However, the hallmark radiological finding of diffuse calcifications in the nuclear ganglia resembles some cases related to the PDGRFB mutation. Genetic investigation revealed a new mutation in the mitochondrial tRNA-arginine gene. Conclusions Brain calcifications are a common feature of mitochondrial diseases, but little is known about their pathophysiology. Here, we describe radiological similarities between a new mitochondrial DNA mutation and other genetic conditions, which are related to Fahr’s disease. These similarities could provide new insights into putative genotype–phenotype correlations.