OBJECTIVETo analyze the clinical characteristics and diagnosis of 2 cases with chylothorax due to primary lymphatic dysplasia and to elevate pediatrician's recognition level for this disease.

METHODClinical manifestations of the children were retrospectively analyzed. Primary lymphatic dysplasia was diagnosed by lymphoscintigraphy.

RESULTThe first patient was a male aged 2-year-7-month who presented with a history of tachypnea for 43 days, fever and sore throat for 5 days at the early stage of the illness. He had a history of external injury before his illness. Physical examination showed his left chest bulging and left side diminished breath sound. His pleural effusion showed dark red (It was divided into two layers after standing, the upper layer turned into milky white, and the lower turned into hemorrhagic liquid) . White blood cell (WBC) count was 9 000×10(6)/L, mononuclear cell was 0.9, polykaryocytes was 0.1, triglyceride was 12.37 mmol/L in the pleural effusion. Contrast-enhanced lung CT (revascularization) showed pericardial effusion and a massive left sided pleural effusion. The second patient was a male aged 9 years and 6 months, who presented with a history of cough for 24 days, intermittent fever, vomiting, abdominal pain for 19 days, and edema of lower limbs for 4 days. Physical examination showed edema in both eyelids, lower extremities and scrotum. The level of albumin was 14 g/L and the titer of Mycoplasma pneumoniae IgM was 1: 320 in the serum. His hydrothorax pleural effusion showed milk white. White blood cell (WBC) count was 74×10(6)/L, mononuclear cell was 0.78, polykaryocytes was 0.22, triglyceride was 1.01 mmol/L in the pleural effusion. Chyle test showed positive in his pleural effusion and seroperitoneum. High-resolution CT of the lung revealed bilateral interstitial and parenchymal infiltration and both sided pleural effusion. Abdominal ultrasound showed giant hypertrophy of the gastric mucosa and massive ascites. Gastroscopy showed giant hypertrophy of the gastric mucosa. Lymphoscintigraphy revealed primary lymphatic dysplasia in both children.

CONCLUSIONPrimary lymphatic dysplasia might occur in children and result in dropsy of serous cavity (chylothorax, chylopericardium, chylous ascites). Dropsy of serous cavity showed bloody or milk white. WBC count might elevate with lymphocyte increasing mostly, triglyceride was often higher than 1.0 mmol/L in dropsy of serous cavity. Primary lymphatic dysplasia can be diagnosed by lymphoscintigraphy.