2008 Volume 48 Issue 2 Pages 130-134
Background. Cancer of unknown origin with mediastinal lymph node metastases is relatively rare. In most of reported cases, the primary lesions were unknown. We encountered an interesting case in which the primary lesion appeared on CT scan taken 30 months after resection of mediastinal lymph node metastases. Case. A 76-year-old man underwent left lower lobectomy+ND2a for adenocarcinoma. He had a solitary lymph node swelling in the contralateral mediastinal space and underwent biopsy via mediastinoscopy, which was diagnosed as a squamous cell carcinoma. Finally, squamous cell carcinoma was seen in 2 lymph nodes resected by mediastinal lymph node dissection via median sternotomy. CYFRA also dropped to near the normal cut-off line. CT scans were taken every half year, and a new lesion was developing in the right upper lobe along with an increase in CYFRA, 30 months after the mediastinal lymph node dissection. Assuming primary lung cancer, right upper lobectomy+ND1 were done. Pathologically, it was squamous cell carcinomas similar to the previously resected mediastinal lymph node metastases. Conclusion. Surgical resection is adequate strategy for cancer of unknown origin with mediastinal lymph node metastases, because the prognosis is good compared with other unknown origin cancers or N2 primary lung cancers. It is necessary to carefully observe cancer of unknown origin with mediastinal lymph node metastases for appearance of the primary lesion.
