Lymphoscintigraphy of Chylous Anomalies: Chylothorax, Chyloperitoneum, Chyluria, and Lymphangiomatosis-15-Year Experience in a Pediatric Setting and Review of the Literature.

In the pediatric setting, lymphoscintigraphy is used mostly for the evaluation of lymphedema. Only a few cases of chylous anomalies and lymphatic malformations imaged with lymphoscintigraphy have been reported in the literature. The aim of this study was to review the use of lymphoscintigraphy in those pathologies. Methods: All lymphoscintigraphy studies performed for chylous anomalies between 2001 and 2017 in our hospital were retrospectively reviewed. The results were correlated to clinical and radiologic findings. Lymphoscintigraphy consisted of sequential imaging after injection of 3.7-9.25 MBq (100-250 μCi) of 99m Tc-filtered sulfur colloid at the level of the feet or hands. Results: Twenty-five studies were performed on 21 patients. Fourteen studies were obtained for the evaluation of chylothorax. Eleven were performed for chyloperitoneum, chyluria, chylopericardium, exudative enteropathy, or lymphangiomatosis. Ten studies were positive for lymphatic leakage, and 1 had uncertain results. After correlation with radiologic findings and follow-up, there were 7 true-negative and 5 false-negative results (previous 67 Ga-interfering activity in 1, injection in only the hands in 3, and a low-fat diet in 1). One study became positive after injection in the feet, and another became positive after a switch to a high-fat diet. Conclusion: Lymphoscintigraphy is a useful tool for imaging lymphatic anomalies in children. Suggestions to optimize results include placing the patient on a high-fat diet, withholding octreotide, injecting the 4 extremities, and imaging with SPECT/CT.