2019 Volume 59 Issue 1 Pages 76-81
Background. It is sometimes difficult to distinguish non-small cell lung cancer with neuroendocrine differentiation from neuroendocrine carcinoma by specimens obtained by a transbronchial biopsy. In the present case, we diagnosed small cell carcinoma by a transbronchial lung biopsy before surgery, but the lesion turned out to be basaloid squamous cell carcinoma with neuroendocrine differentiation according to an examination of a surgically resected specimen. Case. Two tumors were observed in S2 and S3 of the right upper lobe of an 83-year-old man, and we diagnosed the specimen as small cell carcinoma by a transbronchial lung biopsy of the S3 tumor. The patient had chronic kidney disease, so he underwent lung resection instead of definitive chemoradiotherapy. Right upper lobectomy was performed, and the postoperative pathologic diagnosis was basaloid squamous cell carcinoma with neuroendocrine differentiation. The S2 tumor was pulmonary metastasis, the #4R lymph node was positive for cancer, and the pathological stage of lung cancer was IIIA. No recurrence has been recognized in the two years since the surgery. Conclusion. In the pathological diagnosis of micro specimens, a tumor may be non-small cell lung cancer with neuroendocrine differentiation even if it has small cell carcinoma morphology and positive neuroendocrine marker staining.
