Classical Biphasic Pulmonary Blastoma: A Case Report

Abstract

Pulmonary blastomas are a rare aggressive neoplasms comprising 0.25-0.5% of all primary lung tumors and portend a poor prognosis. Recent World Health Orgnisation (WHO) reclassifications separated well differentiated fetal adenocarcinoma and pleuropulmonary blastoma from classic biphasic pulmonary blastoma which is now among carcinomas with pleomorphic, sarcomatoid or sarcomatous elements. The clinical and radiologic features are nonspecific. Surgery is the standard treatment and the efficacy of adjuvant chemotherapy and radiotherapy has not yet been established. We present a case of classic biphasic pulmonary blastoma in a 52-year old male and review the literature.for left pleural tuberculosis treated in 1988. On examination he looked well, had no clubbing. Baseline investigations were done, which included complete blood count, renal function tests, and liver function tests; all were within the normal range. Chest X-ray showed a well-demarcated mass projected over the right hilum. A subsequent chest computed tomography scan with intra-venous contrast (Figures 1,2) confirmed a well-defined 3.8 × 2.5 cm mass arising from the medial segment of the middle lobe. It demonstrated heterogeneous contrast enhancement with few necrotic foci. The mass abutted the mediastinal pleura with no sign of invasion of left atrium. There was no evidence of lymphadenopathy. The liver and adrenal glands appeared normal. CT guided biopsy was done and the smear revealed a biphasic neoplasm composed of epithelial and mesenchymal components suggestive of pulmonary blastoma. CT abdomen and bone scintigraphy showed no evidence of distant metastasis. The patient underwent a middle lobectomy with hilar and mediastinal lymph node dissection. The histopathology of the specimen confirmed the diagnosis of pulmonary blastoma without involvement of the lymph nodes. Post-operative course was uneventful and the patient was discharged on the 4th postoperative day. Due to the lack of certain poor prognostic factors like tumor size IntroductionPulmonary blastomas are a rare aggressive neoplasms comprising 0.25-0.5% of all primary lung tumors. They display a biphasic histology with mesenchymal and epithelial components whose features mimic embryological lung tissues before 4 months gestation. Since the first report by Barrett & Barnard [1], in 1945, over a hundred cases of pulmonary blastoma are reported in the literature. They are currently subdivided in three categories: well differentiated fetal adenocarcinoma, pleuropulmonary blastoma and classic biphasic pulmonary blastoma (CBPB). Surgery is the standard treatment and the efficacy of adjuvant chemotherapy and radiotherapy has not yet been established. We present a new case of this rare lung cancer. ObservationA 52-year-old man presented to the outpatient department with right chest pain of 3 months duration. He denied hemoptysis, dyspnea, fever or weight loss. His past medical history was significant