Langerhans cell histiocytosis: A rare aetiology for fetal pleural effusion

We present fetal pleural effusions associated with Langerhans cell histiocytosis (LCH). We report a case of fetal pleural effusion in late pregnancy. Due to developing rapidly over short period of time, the baby was delivered by caesarean section at 34 weeks gestation. Generalised oedema, sparse haemorrhagic papules, pulmonary involvement, mediastinal mass and liver dysfunction were identified postnatally. Structural malformations, maternal-fetal blood type incompatibility, chromosomal abnormalities and viral infection were excluded. Mediastinal mass biopsy and immunohistochemical examinations confirmed the diagnosis of Langerhans cell histiocytosis (LCH). The baby is currently in a stable condition and undergoing regular chemotherapy. Congenital LCH is a rare aetiology of fetal pleural effusions.