A Rare Case of Metachronous Primary Lung Cancers in a Patient With Primary Hematological and Oncological Malignancies

Abstract

INTRODUCTION: Patients with non-small cell lung cancer have 1 to 2 percent risk of developing second primary lung cancer (SPLC) per year (1). Metachronous SPLCs compromise 60% of cases while remaining cases are synchronous SPLCs (2). Retrospective studies reveal a mean interval period of 55 months between the first and second primary lung cancer (2). We report a case of aggressive SPLC in a patient with existing primary adenocarcinoma of the lung, myeloproliferative neoplasm, primary laryngeal cancer, and primary renal cell carcinoma. CASE PRESENTATION: A 60 year old male with a 40 pack year smoking history was referred for hematologic evaluation in 2004 for leukocytosis, thrombocytosis and erythrocytosis, and was eventually diagnosed with Polycythemia Vera. He was initially treated with phlebotomy; but eventually required hydroxyurea for persistent elevated counts with some benefit. Thereafter, in early 2008 he presented with sore throat and ear pain. He underwent video laryngoscopic biopsy which confirmed a diagnosis of stage 1 squamous cell carcinoma of the epiglottis for which he underwent radiation therapy. He re-presented to his PCP in October of 2008 with total body numbness. Imaging revealed a new right kidney mass, and histology was positive for stage I renal cell carcinoma requiring nephrectomy. On follow up visits, he appeared to be in remission for both laryngeal and renal cancers. A surveillance CT scan in February 2010 revealed a new 9-mm spiculated nodule in the right upper lobe. This nodule was hypermetabolic on positron emission tomography (PET) imaging and biopsy revealed stage 1A adenocarcinoma of the lung. He underwent successful right upper lobectomy in August 2010. In October 2010, patient presented to a local emergency room with dyspnea on exertion. Initial work up for cardiac and thromboembolic etiologies was unreamarkable. PET, CT scan, and bone scans were negative for any malignancy. Due to history of moderate emphysema (FEV1 of 45% predicated value), he was started on bronchodilators which improved dyspnea temporarily until December 2010 when he represented with hemoptysis. Repeat imaging identified a new mass measuring 3 cm x 2.6 cm x 4.7 cm centered around the right distal main stem bronchus. Bronchoscopy guided biopsy was positive for a primary squamous cell lung cancer. He underwent pneumonectomy and is currently able to carry out his activities of daily living despite modest limitations. DISCUSSION: Second primary lung cancers are commonly found in patients who survive more than 3 years after diagnosis of their presenting primary cancer (2). However, the combination of two primary lung cancers with preexisting primary hematological and oncological malignancies is extremely rare. Our patient's presentation with SPLC is extremely rare since he presented within 4 months after right upper lobectomy for adenocarcinoma of the lung. He underwent extensive work up to rule out other common etiologies for his symptoms. This case demonstrates the importance of histological diagnosis of recurrent masses in a patient with preexisting malignancy as it impacts therapy. The only known risk factor that was known in our case was tobacco exposure. He did not have any occupational exposure or known genetic disorder which would predispose him to get multiple primary malignancies. CONCLUSIONS: We present a unique patient with five primary cancers which includes a rare combination of primary hematological and oncological pathology. As of now, no known genetic factor is known that would be responsible for five primary cancers. Further investigation is needed to understand this rare combination of primary cancers.