Intrathoracic Rhabdoid Tumor: A Rare Site in a Jordanian Infant.

Intrathoracic rhabdoid tumors in infants are rare and aggressive malignancies that pose significant diagnostic and therapeutic challenges. We report the case of a previously healthy six-month-old full-term infant admitted with severe respiratory distress and desaturation, requiring admission to the pediatric intensive care unit (PICU) and intubation. Initial evaluation suggested left upper lobe pneumonia, but the patient demonstrated minimal improvement with antibiotics and corticosteroids. Then a chest CT was done and revealed a large, heterogeneously enhancing pleural-based mass compressing the left lung, initially interpreted as an aggressive pleural tumor, such as bronchopleural blastoma. The findings led to the urgent initiation of chemotherapy, resulting in temporary clinical improvement that allowed for extubation and a biopsy to be taken. The initial biopsy indicated a germ cell tumor with yolk sac based on these immunohistochemical markers: SALL-4, cytokeratin, and vimentin. However, the patient's lack of a sustained response to chemotherapy and subsequent clinical deterioration prompted a repeat biopsy, which confirmed the diagnosis of an intrathoracic rhabdoid tumor. Despite aggressive multimodal therapy, the patient developed liver metastases five months after the initial diagnosis and was transitioned to palliative care. This case highlights the tumor's complex behavior and resistance to therapy, and underscores the diagnostic challenges associated with intrathoracic masses in infants, particularly the overlap between germ cell tumors and rhabdoid tumors.