Abstract
Mature cystic teratomas exhibit a variety of tissues within their pathology. In adults, teratomas typically originate in the gonads. However, one of the rarest origins is the lung, making intrapulmonary teratoma (IPT) exceedingly uncommon. In infants, extragonadal teratomas are more common, with only two cases of IPT reported in the literature. While the clinical presentation in infants and adults is similar, fever appears to be unique to infant cases. We present a case of a one-year-old female who exhibited respiratory distress and fever. A chest X-ray revealed an opaque right hemithorax, initially leading to a diagnosis of pneumonia. Despite intravenous (IV) antibiotic treatment, there was no improvement. A subsequent chest computed tomography (CT) scan revealed a large mass with heterogeneous densities occupying the entire right hemithorax, indicative of IPT. The mass was successfully excised, and the infant was discharged on the 11th postoperative day without complications. This case adds to the limited literature on giant IPT in infants compared to the two previously published cases.