THREE PRIMARY LUNG MALIGNANCIES IN ONE PATIENT, WITH EMPHASIS ON PULMONARY BLASTOMAL: A CASE REPORT

Abstract

SESSION TITLE: Lung Cancer 2 SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: : Pulmonary blastoma (PB) is a rare primary lung tumor, accounting for less than 0.5% of all lung cancers. CASE PRESENTATION: Our patient is a previously healthy 43-year-old female with 25-pack-years of smoking, who presented with a two-month-history of hemoptysis, exertional dyspnea, and pleuritic chest pain. Chest CT revealed a 7.8 x 4.3 cm right upper lobe mass. Fiberoptic bronchoscopy (FOB) revealed an obstructing, necrotic, exophytic lesion with a vascular stalk; pathology revealed small cell lung carcinoma (SCLC). Immunohistochemistry was positive for cytokeratin 7, and TTF-1; negative for p63, cytokeratin 5/6, and CD 4; without definitive staining for synaptophysin, and chromogranin. She received 4 cycles of etoposide, and cisplatin, concurrent radiation, and prophylactic cranial irradiation. Repeat CT showed a 75% decrease in tumor size; a PET scan showed no hypermetabolic activity. Repeat FOB showed reduction of the mass to a flat lesion. Given her limited disease, young age, and excellent performance status, a right upper lobectomy with mediastinal lymph node dissection was performed. Pathology revealed pulmonary blastoma with epithelial, and mesenchymal components, pleural invasion (as evidenced by a pleural bleb) with adenocarcinoma-in-situ, and lymph nodal involvement. Immunohistochemistry was positive for cytokeratin 5/6, cytokeratin 7; p63; CDX2; and TTF-1, with focal immunoreactivity for synaptophysin, and chromogranin. As of this writing, the patient is not receiving any further treatment; she is under active surveillance. At her three-month-post-operative-visit, she was in remission. DISCUSSION: Pulmonary blastoma is characterized by histologic resemblance to fetal lung tissue. There are three subtypes: monophasic (well-differentiated fetal adenocarcinoma with epithelial components), classic biphasic (epithelial, and mesenchymal components), and pleuropulmonary blastoma (mesenchymal components). Our patient has SCLC, biphasic PB, and adenocarcinoma-in-situ. Surgery is the mainstay of treatment for PB; postoperative chemotherapy, and radiation are given in select cases. The overall prognosis of PB is poor with two-thirds of patients dying within two years of diagnosis, and a 5-year-survival of 16% (1). Some features that predict a poor prognosis for PB are the biphasic subtype, tumor size > 5 cm, tumor recurrence, lymph node involvement, and metastases at presentation (2). Our patient has the biphasic subtype, with tumor size > 5 cm, and lymph node involvement. CONCLUSIONS: Mixed-cell lung tumors are not uncommon. However, triple synchronous primary lung cancers are rare, and have not hitherto been described with pulmonary blastoma as one of the cancers. Another interesting aspect which makes this case unusual is that the patient may have received unintentionally beneficial (in regard to PB) neoadjuvant therapy (which is usually reserved for an unresectable PB). Reference #1: Classic biphasic pulmonary blastoma: A case report and review of the literature. Van Loo, S.; Boeykens, E.; Stappaerts, I.; Rutsaert, R. Reference #2: Pulmonary Blastoma: A Rare Primary Lung Malignancy. Mahmoud S. Alahwal, Iqbal H. Maniyar, Faiza Saleem, Mariam Alshiekh Case Rep Med. 2012; 2012: 471613. Published online 2012 Sep 19 https://doi.org/10.1155/2012/471613. DISCLOSURES: no disclosure on file for Stephen Brierre; No relevant relationships by Navya Eleti, source=Web Response