INTRODUCTION: Pulmonary blastoma (PB) is a rare neoplasm with a high mortality rate. A subset of PB, biphasic pulmonary blastoma (BPB), is reported to comprise less then 0.25% of all primary non-small cell (NSC) lung tumors and has the highest fatality rate (1).We herein report a case BPB in a 39-year-old African-American (AA) female diagnosed incidentally on a chest x-ray, only thoracotomy and lung resection confirmed the diagnosis. There are less than approximately 200 total cases of PB and of those only 50 adult cases of BPB are described in the literature to date.
CASE PRESENTATION: A 39-year-old AA female with a past medical history significant of hypertension, asthma and a 20 pack year history of smoking tobacco, presented with non specific chest pain and a recent history of unspecified weight loss. She had no prior occupational exposures and history of recent travel. Her father had died of cirrhosis, and her mother was alive at 69 with a medical history of a cerebral vascular accident and coronary artery disease. An EKG and a chest x-ray were requested. The chest x-ray was remarkable for an 8cm X 6cm mass in the right upper lobe. A CT scan of her thorax confirmed the mass as 4.5cm X 9.5cm, bilobular, abutting the mediastinum, with narrowing and displacement of the right upper lobe bronchus. A fiberoptic bronchoscopy with transbronchial biopsy and washings was unmarkable for any abnormal pathology. A mediastinoscopy and biopsy of the lesion also did reveal any diagnosis. Following this she underwent an exploratory thoracotomy and a right upper lobectomy, which on pathology revealed BPB, with prominent stromal overgrowth showing features of a spindle cell carcinoma with anaplastic giant cells. She remains alive to date 7 years in her follow-up with no reoccurrence of the tumor. Our AA patient is one of the longest survival case in USA to date.
DISCUSSIONS: PB is a rare malignant neoplasm of the lung comprised of epithelial and mesenchymal elements that recapitulate the fetal lung at 10-16 weeks' gestation.Barrett and Barnard originally described the tumor in 1945 (2), with subsequent modifications to the terminology made by Barnard and later by Spencer. 75 % of all cases of PB occur in children of less than 5 years of age with a further 20% of cases occur in individuals less than 20 years of age. The exact histogenesis of PB continues to be debated but an association with heavy smoking has been described.Pathologically PB is classified into three types: (1) well differentiated fetal adenocarcinoma (WDFA) and (2) Pleuro-pulmonary blastoma (occurs predominantly in children and is the most common variant) and (3) BPB is composed of both epithelial and mesenchymal malignant cells. Biphasic histology and a size >5 cm in greatest dimension are considered to be very poor and dire prognostic indicators.
CONCLUSION: The prognosis of PB, regardless of histology, is poor. About 50% die with in 3-6 months after diagnosis. Francis and Jacobsen reported the overall 5-year survival to be 16%. To date the only curative treatment is surgical resection; both radiotherapy and chemotherapy have been attempted without any reproducible measure of success. We emphasis, when suspicion is high, surgery is not only the means of diagnosis but also cure.
DISCLOSURE: Amir Khan, None.