Primary Multiple Pulmonary Primitive Neuroectodermal Tumor

Primitive neuroectodermal tumors (PNETs) arising directly from the lung are extremely rare but particularly aggressive neoplasms. Although thoracic PNET usually develops on the chest wall, there have been reports of primary Ewing sarcoma/PNET of the lung. We present the case of a 16-year-old male with PNET diagnosed following histologic and immunohistochemical examination of a videoassisted thoracic surgical biopsy. As typically occurring for these tumors, the diagnosis was initially delayed in our patient and prognosis was poor despite aggressive surgical resection and postoperative chemotherapy. We attempted to explore the use of targeted pharmacotherapy through high-throughput sequencing in this case. We found that this treatment using Avastin and Cetuximab could provide a new therapeutic direction for PNET. PNENTs arising from the lung parenchyma without pleural or chest wall involvement are extremely rare. Although uncommon, if the pathological features are similar to Ewing sarcoma, PNENTs should be kept in mind, and the target therapy may be a potent treatment for this disease. (Medicine 94(27):e1136) Abbreviations: CT = computed tomography, IHC = immunohistochemical, PNET = primitive neuroectodermal tumor. ong, MD, PhD, Xin Shi, MD, , and Jun Chen, MD, PhD adolescents or young adults (usually younger than 35 years) with a slight male preponderance. PNET is a malignant neoplasm comprising small, undifferentiated neuroectodermal cells, and the common origin sites are the long bones, such as the femur and humerus as well as the pelvic bones. Reports have also noted the presence of PNET in the liver, kidneys, and adrenal glands. In the chest region, PNET commonly arises from the chest wall; this is usually referred to as an Askin tumor. Cases of PNETs arising from the lung parenchyma without pleural or chest wall involvement are extremely rare. To the best of our knowledge, multiple pulmonary PNTEs without chest wall involvement in 16-year-old adolescent have not been reported to date. PRESENTING CONCERNS A 16-year-old boy was admitted with the chief complaints of shortness of breath and occasional chest pain of about 3 days duration. He had no other complaints and his past history was unremarkable. He denied smoking and had no family history of malignancy. A review of systems was noncontributory. Peripheral blood count, baseline serum chemistry screening, and urinalysis were normal on admission, as were tumor biomarker tests (alpha fetoprotein, serum ferritin, carcinoembryonic antigen, antigen 19-9, carbohydrate antigen 24-2, prostate-specific antigen, neuron-specific enolase, Cytokeratin 19 Fragment (CYFRA21-1), and squamous cell carcinoma antigen) and a purified protein derivative (PPD) for tuberculosis. CLINICAL FINDINGS As shown in Figure 1A, B, a computed tomography (CT) scan of the chest imaged multiple soft tissue nodules in both lungs, especially in both inferior lobes. The positron emission tomography-computed tomography (PET-CT) with fluorodeoxyglucose examination of total body revealed multiple soft tissue density nodules, with an approximate diameter 0.5 to 1.1 cm, in both lungs with a tracer concentration of SUVmax (standardized uptake value) of 1.0, and without correlative abnormality (Figure 1C). No other abnormal tracers were present. Magnetic resonance imaging of the brain was normal. Bronchoscopy was not performed. DIAGNOSTIC FOCUS AND ASSESSMENT In order to establish the pathological diagnosis, a left-sided video-assisted thoracoscopy (VAT) was performed and 6 nodules in the lingual segment were removed. During the operation, a number of nodules were present on the surface of both left lung lobes with protrusion, but under the visceral pleura. As shown in Figure 2, histopathologic examination hat exhibited small, round, and mild ells with more cytoplasm; and partial ytoplasm. The majority of cells exhibited www.md-journal.com | 1