What happened, in summary

This 51-year-old nonsmoking woman had no respiratory symptoms when an abnormal chest X-ray was found during a periodic medical check. She had no cough, hemoptysis, shortness of breath, fever, or pneumonia, and her examination and routine laboratory testing were unremarkable. Chest radiography showed a 3.2 × 2.8 cm mass in the left peripheral lung field. CT showed a well-defined 3 × 2.9 cm mass bordering the visceral pleura in the lingular segment of the left upper lobe. Percutaneous needle biopsy suggested a salivary gland tumor, a rare diagnostic possibility in the lung. PET-CT showed uptake in the left upper-lobe mass, and no clinical or laboratory findings suggested nodal disease before surgery. Because the mass was localized and the biopsy suggested a rare salivary-gland-type tumor, the team proceeded with surgical treatment rather than chemotherapy first. She underwent video-assisted thoracoscopic left upper lobectomy with lymph node dissection. The resected tumor was well circumscribed, gray-white to yellow, and measured 3.3 × 2.4 × 1.9 cm. Microscopy showed epithelial-myoepithelial carcinoma, with tubular and glandular structures containing eosinophilic material mixed with solid spindle and polygonal cell areas. The inner tubular layer showed epithelial features, while the outer layer showed myoepithelial features. Immunohistochemistry supported this biphasic pattern: EMA was positive in the inner epithelial components, actin was positive in the outer tubular and solid areas, and S-100 was focally positive. Final staging was pT2aN0M0, Stage IB. She did not receive adjuvant chemotherapy or radiation. As of February 2014, 16 months of follow-up showed no local recurrence or distant metastasis.