Adenocarcinoma of the lung seldom metastasizes to the nasopharynx and there are sparse reports in the literature concerning this issue. From the report available, nasopharyngeal metastasis usually accompanied by other distant metastases and there was no long-term survivor reported thus far. In this report, we present a patient with adenocarcinoma of the lung with nasopharyngeal metastasis who was able to achieve long-term survival after radiotherapy to the nasopharynx.
A 51-year-old male who was a chronic smoker with an otherwise unremarkable past medical history, presented with bloodstained sputum for 5 months. Subsequently, he was confirmed to have 5 cm adenocarcinoma over left upper lobe without radiological evident of distant metastasis. The patient was treated with left upper lobe lobectomy and mediastinal lymph nodes sampling. The pathological staging was stage IB. The patient ran an uneventful post-operative course and was discharged on the 5th post-operative day.He developed haemoptysis two months after the operation. Bronchoscopic examination revealed a 1 cm nasopharyngeal pedunculated lesion with surface ulceration and biopsy of that lesion confirmed to be adenocarinoma. The histomorphological pattern of the nasopharyngeal tumor (Fig 1) was similar to that of the pulmonary tumor (Fig 2). Immunohistochemically, both tumors showed the same profile of expressing cytokeratin 7 and thyroid transcription factor I, but not cytokeratin 20. In situ hybridization for EBV RNA was also negative. This profile demonstrated that both tumors were clonal, and were of pulmonary origin, thus confirming a nasopharyngeal metastasis of the lung adenocarcinoma.Metastatic work up including bone scan and ultrasonography of the abdomen excluded other distant metastasis. The patient was referred to oncologist and subsequently received radiotherapy to the nasopharynx. Repeated nasopharyngoscope showed complete regression of the lesion. The patient has been followed up for five years since the initial operation and remains disease free. A repeated position emission tomography does not reveal any suspicious focus of uptake.
It was estimated that about 60% of non-small cell carcinoma metastasize at the time of presentation. There are reports in the literature that mentioned rare sites of metastases from lung cancer, however, there is no report of adenocarcinoma of lung with solitary nasopharyngeal metastasis. In our locality, malignancy occurring in the nasopharynx is usually undifferentiated carcinoma (nasopharyngeal carcinoma), which is associated with EBV genome within the tumor. In this case, the histomorphologic pictures of both tumors were similar, and the characteristic features for undifferentiated carcinoma of the nasopharynx were absent. Both tumors showed similar antigenic profiles, which were consistent with that of a pulmonary origin. Hence this case is highly unusual in terms of a solitary metastasis to the nasopharynx, without involvement of other organs and the mechanism of such metastatic spread remains a matter of speculation. In this particular case, there are two learning points. First, for patient presented with haemoptysis after lung resection, a surveillance of nasopharynx should be undertaken during bronchoscopic evaluation. Second, long-term survival is still possible despite confirmation of metastatic lung cancer, hence, nasopharyngeal metastasis from lung primary may represent a different clinical entity which responses to radiotherapy.
Nasopharyngeal metastasis from lung primary is a rare condition and often carries poor prognosis. There is a possible role of radiotherapy in the treatment of solitary head and neck metastasis from adenocarcinoma of lung.
Randolph Wong, None.