Endobronchial metastases: a clinicopathological analysis

It is important to distinguish endobronchial metastases (EBM) from both primary lung cancers and benign lesions, as treatment will differ. The clinicopathological characteristics of EBM cases were documented to see whether any distinguishing features exist.

Histological cases diagnosed as EBM in the pathology laboratory of a tertiary hospital were re-evaluated. Symptoms, primary tumour sites, recurrence interval, radiological and bronchoscopic features, and histopathological properties were assessed.

There were 18 cases (eight female, 10 male) with EBM. All were diagnosed by bronchoscopic bronchial biopsy. The primary tumour sites were: colorectal (4), breast (3), renal (3), lymphoma (3), rhabdomyosarcoma (2), bladder (1), thyroid (1) and malignant melanoma (1). The mean time from the diagnosis of the primary tumour to their presentation was 3.89+/-1.09 (range, 0--19) years. In five patients, EBM was diagnosed synchronously with their extra pulmonary primary tumour. Two had other metastatic sites. Haemoptysis and cough were the more common symptoms. Interestingly, three patients were asymptomatic. There was no predilection for a particular airway segment to be involved but a predilection for the upper lobe existed. Endoscopic appearance was polypoid in 10 cases and mucosal infiltration in the remainder. Histopathological examination revealed epithelial tissue at the surface of the tumour in nine cases and four of these were metaplastic. In all but one there was inflammation, mainly lymphocytic. Necrosis was present in 10 cases and bleeding was seen in four. There were no statistically significant differences between the level of lymphocytic inflammation and other clinicopathological parameters.

EBM is a rare condition that can be synchronous or occur late. Surprisingly, it can be asymptomatic. It is usually found in the upper lobes. Lymphocytic inflammation is a common histopathological finding. There is need for further studies to clarify the clinical importance of EBM.