A 71–year–old man with a past history of long standing asthma presented with productive cough for 1 week and nausea, vomiting, diarrhea, fevers, headache, and generalized weakness for 1 day. In the last 6 months, he had been extensively evaluated for recurrent asthma exacerbations refractory to treatment. Examination was remarkable for generalized flushing, hypotension, tachycardia, and wheezes in the right lung fields. Blood work demonstrated neutrophilic leukocytosis. Chest X–ray was unremarkable. CT abdomen and pelvis showed a right lung infra–hilar mass, left lung basal infiltrate, and multiple hepatic lesions suspicious for metastases. On detailed history, the patient stated that he had several episodes of flushing associated with diarrhea and headache in the last 6 months. CT chest demonstrated endobronchial occlusion of the right lower lobe bronchus. CT guided liver biopsy and bronchoscopic biopsy of the right lung mass revealed metastatic low grade neuroendocrine carcinoma. The final diagnosis was low grade endobronchial carcinoid tumor with liver metastases and carcinoid syndrome (CS). Octreotide scan showed diffuse abnormal uptake throughout the liver and increased focal uptake in the right lung base. Serum chromogranin and 24 hour urine 5–hydroxy indole–acetic acid (5–HIAA) levels were elevated at 32,400 ng/ml and 523 mg/24hours, respectively. He was started on octreotide for symptom control and was referred to oncology for further management.
Bronchial carcinoids (BC) comprise 1 to 5% of lung tumors and 20% of all carcinoids. BC may be classified as typical (well differentiated neuroendocrine tumors) or atypical (well or poorly differentiated neuroendocrine carcinomas). Only 10% of BC are atypical and are associated with an aggressive clinical course. Clinical features of BC include cough, hemoptysis, unilateral wheezing, or recurrent pneumonia. Less than 5% of BC present as CS which are also classified as typical or atypical. Typical CS presents with diarrhea, flushing, bronchoconstriction, and abdominal cramps. BC lack the enzyme that converts 5–hydroxy tryptophan to serotonin. They produce 5–hydroxy tryptophan and histamine instead and present as atypical CS with prolonged flushing, headache, hypotension, facial edema, and wheezing. Our patient initially had symptoms of BC or atypical CS that were being treated as asthma exacerbations. Due to lack of characteristic symptoms, BC are misdiagnosed as asthma or COPD and diagnosis may be delayed for approximately 15 months from the first symptoms.
Asthma and COPD are common causes of wheezing but clinicians should consider other causes like BC when appropriate treatment for asthma and COPD have failed. Prompt diagnosis mandates comprehensive history. CT and bronchoscopy should be considered in all cases of refractory asthma or COPD. Bronchial carcinoid is a potentially curable tumor if detected and treated early. Not every wheeze is asthma, especially if the wheeze is unilateral.