Combined neuroendocrine small cell carcinoma of trachea with crescentic glomerulonephritis as a paraneoplastic manifestation

A middle aged female presented with history of breathlessness and swelling of legs of 2 weeks duration; the clinical and laboratory picture was suggestive of rapidly progressive renal failure and the kidney biopsy revealed a crescentic glomerulonephritis. Her renal function improved with the steroid therapy; in view of persistent breathlessness despite good diuresis chest radiograph was repeated which showed reduced lung volume on right and compensatory emphysema on the left side; a computerized tomography (CT) scan of the thorax showed a mass lesion partially obliterating the right main bronchial lumen. The mass on histopathology revealed small cell neuroendocrine carcinoma (SCNC) with adenosquamous carcinoma. To our knowledge only one case of neuroendocrine tumor presenting as a crescentic glomerulonephritis has been reported in the literature.