Nephrotic syndrome as paraneoplastic manifestation of a primary pulmonary lymphoepithelioma-like carcinoma.

We present a case of nephrotic syndrome secondary to a membranous glomerulonephritis (MG), in a nonsmoking female with a solitary pulmonary nodule, which did not show growth during 2 years of followup. A biopsy by videothoracoscopy showed a granulomatous non-neoplastic process with giant multinucleated cells. The appearance of a nephrotic syndrome and its interpretation as paraneoplastic revealed the existence of a primary pulmonary lymphoepithelioma-like carcinoma (LELC), a very rare pulmonary tumor. After resection of tumor there was a complete recovery from the nephrotic syndrome. This case highlights how the investigation of paraneoplastic syndromes can help in the early diagnosis of some malignancies.