Pulmonary miliary papillary/micropapillary adenocarcinoma manifesting as carcinomatous encephalitis.

The histological pattern and the associated molecular aberrations have an important bearing in the prognosis of pulmonary adenocarcinomas. Papillary and micropapillary growth patterns with mutations in epidermal growth factor receptor and anaplastic large-cell lymphoma kinase rearrangements have an aggressive clinical course. We report one such cancer in a 49-year-old woman, where it assumed a miliary pattern in the lungs, and the patient presented with neurological symptoms related to carcinomatous encephalitis, an infrequent metastatic manifestation.