Calcified brown fat necrosis in new born can be diagnosed on plain film

Brown fat necrosis is subclinical, diagnosed on plain film, and likely self-limited, according to a study published in the Indian Journal of Radiology and Imaging. It occurs in term and preterm infants who have undergone significant systemic stress and carries a poor prognosis.

The study was conducted by Eleza T Golden, Department of Radiology and Imaging Sciences, Children's Healthcare of Atlanta and Emory University, Atlanta, Georgia, and colleagues to describe the radiographic appearance of subclinical calcified brown fat necrosis and the associated clinical and laboratory findings.

Brown fat is present during development of the fetus and persists in neonates. It is responsible for the maintenance of body temperature and is prone to ischemia. Calcific brown fat necrosis has been described in infants with congenital heart disease (cyanotic and acyanotic). Neonatal risk factors for the condition include meconium aspiration, macrosomia, hypoxic-ischemic encephalopathy with or without cooling, and congenital heart disease.

For the study, Picture Archiving and Communications Sytem (PACS) was searched using keywords “soft tissue calcification” and “chest.” The clinical record was searched for prior cardiac surgery, bypass, Extracorporeal Membrane Oxygentation (ECMO) and prostaglandin use. Age when calcifications were first detected, location, resolution, and associated laboratory abnormalities were recorded.

The researchers found that out of the nine identified patients, none had skin lesions. All patients had congenital heart disease and had experienced cardiac/respiratory arrest and/or severe hypotension 1–6 weeks before soft tissue calcifications occurred. Calcifications resolved by 9 weeks to 5 months in 3 patients. The remaining were either deceased or lacked follow-up imaging. Renal ultrasound was performed in all but 1 patient. Nephrocalcinosis was only seen in 1 patient.

Based on the study, the authors concluded that brown fat necrosis is subclinical, diagnosed on plain film, and likely self-limited. It occurs in term and preterm infants who have undergone significant systemic stress and carries a poor prognosis. It has previously been described in term infants with congenital heart disease treated with prostaglandins. Rather than medication related, it may be related to hypoxic/ischemic insult and occurs in both term and premature infants with underlying cardiac disease who experience cardiac or respiratory arrest with hypotension.

How to cite this URL:
Golden ET, Dickson P, Simoneaux S. Brown fat necrosis with calcifications in the newborn: Risk factors, radiographic findings, and clinical course. Indian J Radiol Imaging [serial online] 2018 [cited 2018 May 9];28:107-10. Available from: http://www.ijri.org/text.asp?2018/28/1/107/228707