Fatty changes as a misleading factor in the evaluation with ultrasound of superficial lymph nodes

The object of this paper was to investigate lipoplastic lymphadenopathy in superficial locations with ultrasound. We selected 110 patients with a total number of 247 nodes with a central hyperechoic area extended for more than one third of the transverse diameter. We considered gender, age, body mass index (BMI), and associated disease such as thyroid disorders and diabetes. For each lymph node, we measured the long:short axis ratio and the parenchyma:fat (P:F) ratio. Differences between mean P:F ratio in diabetic and nondiabetic patients were significant (p = 0.045). Mean P:F ratio was negatively related to BMI (r = 0.62,p = 0.015) and age (r = 0.54, p = 0.024). All of the nodes examined with a mean P:F ratio <= 1.2 (58) were found in patients older than 72 y and with a BMI higher than 27.8. Fatty involution may mimic a macrometastasis at palpation and may cause diificulties in US detection.