INTRODUCTION: Bronchial carcinoid is a rare tumor found in multiple endocrine neoplasia (MEN-1). The MEN-1 gene has been implicated in the pathogenesis of sporadic lung carcinoids, and bronchial carcinoids carrying the MEN-1 gene are more often the aggressive atypical carcinoid. We report the case of a patient with a solitary pulmonary nodule accompanied by fevers, flushing, and wheezing.
CASE PRESENTATION: A 68-year-old man with a long smoking history presents to pulmonary clinic with complaints of flushing, fevers, wheezing, and dyspepsia. Family history was unremarkable. Computed tomography (CT) of the chest showed a 1.5 centimeter solitary pulmonary nodule located near the airway. Bronchoscopy revealed a trail of blood from the right lower lobe bronchus, and endobronchial biopsies revealed a typical carcinoid tumor. Somatostatin receptor scintigraphy (OctreoScan) showed uptake positivity for the lung lesion. The liver was normal on OctreoScan and triple-phase CT. Due to the carcinoid syndrome and dyspepsia, endoscopy was performed and a gastric carcinoid was resected. Finding multiple neuroendocrine tumors (no liver metastasis) lead us to consider the diagnosis of MEN-1. Magnetic Resonance Imaging (MRI) of the brain then revealed a two centimeter pituitary tumor that upon excision demonstrated a prolactin staining positive adenoma. He was diagnosed with MEN-1. Since the patient was an index case of MEN-1 with atypical features, he underwent MEN-1 gene testing, which was negative. The patient recovered from his adenoma resection and was discharged home. He returned shortly thereafter with polyneuropathy, dementia, and pneumonia. He expired one year later without definitive treatment of his bronchial carcinoid.
DISCUSSION: Carcinoid tumors are neuroendocrine tumors of low malignant potential that can arise from the gut or lungs. While carcinoid tumors in the gut may present with the typical “carcinoid syndrome”, carcinoid tumors from the lung are usually asymptomatic unless they cause airway obstruction. Our finding of a symptomatic lung carcinoid led to the discovery of a gastric carcinoid. The typical pattern of metastatic spread of GI carcinoid to the lung involves metastatic disease in the liver. However, our patient had no evidence for liver involvement. We concluded that our patient demonstrated multifocal carcinoid, which can be seen in MEN-1 syndromes. This was confirmed by the finding of an asymptomatic prolactin-secreting pituitary adenoma. While genetic screening can identify 80% of these patients, 20% may carry as yet undescribed genetic mutations. Our patient also developed a wasting neurological syndrome that despite extensive testing could not be fully characterized but may have been related to his underlying MEN-1.
CONCLUSIONS: 1. In patients who present with carcinoid syndrome and an isolated bronchial carcinoid, a further work-up for a gastrointestinal source is indicated. 2. It is important to consider MEN-1 in the differential diagnosis of a patient with multiple neuroendocrine tumors that are seemingly unrelated (no liver metastasis). Additional imaging of the pituitary and pancreas and screening for hyperparathyroidism may be indicated. 3. Patients with MEN-1 gene mutations usually have more aggressive bronchial carcinoids.
Reference #1 Fink G, Krelbaum T. Pulmonary Carcinoid: Presentation, Diagnosis, and Outcome in 142 Cases in Israel and Review of 640 Cases From the Literature. Chest. 2001;119;1647-1651.
Reference #2 Debelenko L, Brambilla E. Identification of MEN1 gene mutations in sporadic carcinoid tumors of the lung. Human Molecular Genetics. 1997;6(13): 2285-2290.
DISCLOSURE: The following authors have nothing to disclose: David Collins, Gurinder Sidhu, Michael Peterson
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