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Vol.42 No.4 contents | Japanese/English |
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- Case Report -
Resection of A Primary Lung Lesion After Resection of A Malignant Hilar Lymph Node of Unknown Origin
Yoshihiro Suzuki1, Nobuo Ogawa1, Naoki Ishiwa1, Takaaki Ito21Department of General Thoracic Surgery, Kanagawa Cardiovascular and Respiratory Center, Japan, and 2 First Department of Pathology, Yokohama City University, Japan
Background. We report a rare case with a sole cancer focus in a hilar lymph node. There are few cases in which a primary lesion was revealed and resected after the removal of a malignant lymph node. Case. A 41-year-old man was followed up after resection of a right hilar lymph node with undifferentiated carcinoma and no suspected primary lesion. A thorough systemic examination revealed no primary lesion. Seven years after the resection, a small nodule suspected to be carcinoma 10 mm in diameter in the right lower lobe (S6) was detected by CT and operation was performed. On a diagnosis of adenocarcinoma by frozen section examination, we performed right lower lobectomy and lymph node resection. The histopathological examination revealed that the nodule was a moderately differentiated adenocarcinoma with a partial undifferentiated focus, which was similar to the histology of the previously resected lymph node. Immunohistochemical staining showed that both lesions were negative for surfactant apoprotein (SA-P) but were positive for p53 and thyroid transcription factor-1 (TTF-1), a useful diagnostic marker for lung cancer. This appears to indicate that TTF-1 is more sensitive than SA-P in lung tissue. Furthermore, there are few cases of adenocarcinoma compared with the incidence of thyroid cancer and lung cancer. Those histological findings, immunological examinations and clinical findings all suggested that the lung tumor was a stage IIA (pT1N1M0) primary lung cancer with a lymph node metastasis. This patient is alive without recurrence at 2 years after lobectomy. Conclusion. In treating hilar lymph node cancer of unknown origin, we recommend an active approach comprising resection of the lymph node and meticulous long-term follow up. Once the primary lesion is found, it should be resected as well.
key words: Unknown origin cancer, Lymph node metastasis, Lung cancer
Received: February 4, 2002
Accepted: May 22, 2002
JJLC 42 (4): 283-287, 2002
