Pulmonary metastasis of epidermoid carcinoma of the larynx: a case with an interstitial pattern of growth

We describe a pulmonary metastasis from a laryngeal epidermoid carcinoma, characterized by an interstitial pattern of growth. The patient, a 71-year-old man, smoker, presented with a large laryngeal neoplasm and with two pulmonary masses, one located in the apex and the other in the lower lobe of the right lung. The patient underwent a total laryngectomy and a right pneumonectomy and he died from neoplastic progression 2 years after surgery. Microscopically, the laryngeal tumour was an epidermoid carcinoma and the apical pulmonary mass was an adenocarcinoma. The pulmonary neoplasm of the lower lobe, 5.5 cm across, was an epidermoid carcinoma that we interpreted to be a metastasis from the larynx. The case is peculiar because tumour cells proliferated exclusively in the interstitium. When extensive as in our case, this pattern of growth is rare and it may pose some diagnostic problems.