Elevated CA 19-9 levels observed in association with a pulmonary neuroendocrine tumour and amyloid

Investigations completed in a 77-year-old ex-smoker presenting with weight loss showed raised CA 19-9 levels. The findings of chest radiograph, abdominal computed tomography (CT) and gastrointestinal endoscopic examinations were all normal. On follow-up, the patient developed left upper lobe collapse on chest radiograph with increasing CA 19-9 levels. Chest CT findings suggested the presence of a left upper lobe tumour. The results of a biopsy of the left upper lobe nodule seen on bronchoscopy suggested a diagnosis of amyloidosis; however, this was not the only diagnosis. The left upper lobe mass comprised a neuroendocrine tumour with amyloid deposition just beneath the bronchial epithelium and focally between the nests of the tumour cells. We report and discuss this uncommon association and presentation.