What happened, in summary

This 6-year-old boy had 1 month of fever, cough, wheezing, and coughing up blood. Chest X-ray initially suggested a foreign body with post-obstructive pneumonia, and medication did not improve his symptoms. Routine blood, biochemical, and microbiology testing was unremarkable. CT of the chest then showed an oval mass with a spiculated margin in the right hilar region and distal segmental atelectasis. Bronchoscopy found a small nodular growth with mucosal erosion in the apical segmental bronchus of the right lower lobe. Bronchoalveolar lavage showed a few atypical squamous cells, while post-bronchoscopy sputum was unremarkable. CT of the abdomen and pelvis showed no metastatic deposits. He underwent lobectomy for the lung lesion. The resected right lower-lobe specimen showed a grey-white oval mass with solid and cystic areas extending into the lung parenchyma. Histology showed mixed solid and cystic growth, with sheets of epidermoid cells, squamoid and intermediate cells, mucus-filled cysts, and columnar cells with mucin-rich cytoplasm that stained positive with periodic acid-Schiff. The final diagnosis was intermediate-grade mucoepidermoid carcinoma of the right lower lobe. Lymphovascular invasion was negative, and lymph nodes did not contain metastasis, supporting localized Stage I disease. His postoperative course was good. Because the tumor was localized and low/intermediate grade, no adjuvant chemotherapy or radiation was given. At 1 year after resection, he had no signs of tumor recurrence. This pediatric diagnosis is unusual because lung mucoepidermoid carcinoma is rare in children and can initially mimic infection or airway obstruction before surgical pathology clarifies the diagnosis. The lack of nodal disease supported observation after surgery.