NEUROENDOCRINE TUMOR OF LUNG PRESENTING AS COPD AND TREATMENT OUTCOME ON LONG-TERM FOLLOW-UP

Abstract

PURPOSE: Neuroendocrine tumors (NET) comprise 25% primary lung cancers. But still there is lack of consensus regarding management. We discuss such a case presenting like COPD, ultimate diagnosis, management and long-term follow-up. METHODS: A 40-year-old man with 15 pack-year smoking history presented on May 2013 with cough and sputum production for 1 month and breathlessness for 10 days. On auscultation, breathe sound vesicular with prolonged expiration and bilateral wheezes. Chest X-ray was unremarkable, spirometry consistent with obstructive airway disease. Symptoms subsided on medication. Seven months later, he presented with worsening dyspnoea. HRCT showed a soft tissue density lesion at subcarinal region. Bronchoscopy revealed a submucosal tumor nearly occluding right principal bronchus, involving carina and lower trachea. Biopsy was taken via rigid scope, but histopathology was inconclusive. Surgical exploration was planned. Right thoracotomy was done with excision of right principal bronchial tumor and bronchoplasty with resection of subcarinal lymph node. Histopathology revealed neuroendocrine tumor. Immunohistochemistry showed synaptophysin and chromogranin positive, Ki67 negative. Features compatible with well differentiated neuroendocrine carcinoma (carcinoid tumor). RESULTS: Oncology team started cisplatin and etoposide. Periodic FOB and CT scan revealed no residual disease. He is under observation for last 5 years and doing well. CONCLUSIONS: Surgery is the treatment of choice according to TNM classification. Currently, there is no consensus on adjuvant chemotherapy after complete resection. Clinical trials are needed in this setting. CLINICAL IMPLICATIONS: Clinical presentation of pulmonary NET varies according to it’s location and rarely by hormonal hypersecretion. Many patients present with symptoms that often mimic other respiratory conditions, thus complicating diagnosis.