LUNG - Lymphangitis carcinomatosa (from a primary breast carcinoma)

The specimen consists of portion of the lower lobe of a lung. There is infiltration of the lymphatics by secondary carcinoma. This can be seen on the pleural surface where the lymphatics are outlined as a white network. The cut surface of the lung shows a variegated colour, with pale areas being tumour. The importance of this metastatic pattern is that it can be misinterpreted on imaging as a diffuse non-neoplastic process.
This woman presented at age 46 with a six-week history of increasing dyspnoea, pleuritic chest pain and haemoptysis. One year before, an infiltrating ductal carcinoma of the breast had been treated by simple excision. 3 months later a recurrence was apparent and a simple mastectomy was carried out. At autopsy, tumour was demonstrated in lung, pericardium, axillary nodes, ovary, and in the mastectomy scar.