Ann Thorac Surg 2001;72:285-287
© 2001 The Society of Thoracic Surgeons
Case report
Primitive neuroectodermal tumor of the pulmonary hilum in an adult
Fritz J. Baumgartner, MDa,
Bassam O. Omari, MDa,
Samuel W. French, MDb
a Division of Cardiothoracic Surgery, Harbor-UCLA, Torrance, California, USA
b Division of Pathology, Harbor-UCLA, Torrance, California, USA
Accepted for publication May 26, 2000.
Address reprint requests to Dr Baumgartner, 3791 Katella Ave, #201, Los Alamitos, CA 90720
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Abstract
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A rare case of a thoracic primitive neuroectodermal tumor in an adult is presented. In this case, the aggressive, rapid progression characteristic of the disease was evident.
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Introduction
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Primitive neuroectodermal tumors (PNET), described originally by Askin and colleagues [1], are infrequent thoracic tumors found in infants and children [2]. Thoracopulmonary Ewing’s sarcoma is thought to overlap considerably with PNET, and the lesions can be grouped together as malignant small round-cell tumors [2, 3]. The condition of PNET is exceedingly rare in adults [4]. We herein report the PNET entity in an adult and the rapid progression of the disease after a misleading diagnosis at initial biopsy.
A 26-year-old Japanese American woman presented with vague symptoms of shortness of breath and chest pain. Chest film and computed tomography revealed a large mediastinal mass near the hilum (Fig 1). A left anterior mediastinotomy through the second interspace was done. Biopsy of the lesion resulted in profuse bleeding, which was locally controlled. Pathologic examination of the tissue was consistent with a fibrovascular lesion, probably hemangioma. Because of proximity to hilar structures, it was not considered advisable to attempt resection, and therefore a course of radiation treatment was given. Seven months after the initial procedure, the patient re-presented with worsening symptoms and massive enlargement of the lesion, assessed by chest film and computed tomography (Fig 2).
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Fig 1. (A) Chest roentgenogram and (B) computed tomographic scan of patient with primitive neuroectodermal tumor lesion on initial presentation.
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Fig 2. (A) Chest roentgenogram and (B) computed tomographic scan of same patient 7 months later, showing progression of disease.
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A left pneumonectomy was done, and the subsequent pathologic examination revealed PNET histology (Fig 3). Over the next several months, the patient underwent extensive radiation and chemotherapy treatments, including isophosphamide, etoposide, cyclophosphamide, doxrubicin, and vincristine regimens. She required a thoracic laminectomy for cord compression from a metastatic intrathecal tumor. Shortly thereafter, she developed brain metastases and bone marrow involvement; she ultimately succumbed to the disease 8 months after the pneumonectomy.
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Fig 3. (A) This specimen of the primitive neuroectodermal tumor (PNET) from pneumonectomy appeared as sheets of small cells with scant cytoplasm and focal necrosis. (Hematoxylin and eosin; x312.) (B) The specimen stained positive for monoclonal antibody 013 to the MIC II gene product. This antibody is an immunohistochemical marker for PNET/Ewings sarcoma and exhibits positive brown staining of the cell membranes. Frequent mitoses are seen. (x624.)
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Comment
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Lesions of PNET are typically painful, invasive thoracic tumors that may develop on and invade the chest wall, lung, or mediastinum. They are generally soft and fleshy, with areas of hemorrhage and necrosis. Although the tumors were classified by Askin and colleagues [1] with thoracic autonomic neurogenic tumors, the PNET cells do not produce biologically active substances detectable in the blood or urine. A similar chromosomal translocation occurring in both Ewing’s sarcoma and PNET lesions suggests that these tumors are closely related. Characteristic PNET pathologic findings include Homer-Wright pseudorosettes and uptake of neuron-specific enolase stain [5]. Aggressive surgical resection with additional radiation has led to disease-free survivors [4, 6], although the mean life expectancy is less than 1 year.
The present case describes one of the few reported cases of the PNET entity in an adult. The initial biopsy was misleading, most likely because the tumor itself was not biopsied: only the tumor’s surrounding fibrovascular casing was biopsied. Not until pneumonectomy was performed for relentless invasion was the diagnosis made. The recurrence of the tumor in the central nervous system is unusual, as most recurrences are in the bone and sympathetic chain.
Primitive neuroectodermal tumor lesions are aggressive and usually lethal; they should be considered in the differential diagnosis of thoracic tumors regardless of the age of the patient. Once a diagnosis of PNET has been made, early wide excision of the tumor, along with multimodality chemo- and radiotherapy, should be undertaken to offer any hope of a long-term cure.
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References
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Askin F.B., Rosai J., Sibley R.K., Dehner L.P., McAlister W.H. Malignant small cell tumor of the thoracopulmonary region in childhood. Cancer 1979;43:2438-2451.[Medline]
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Shamberger R.C., Tarbell N.J., Perez-Atayde A.R., Grier H.E. Malignant small round cell tumor (Ewing’s-PNET) of the chest wall in children. J Pediatr Surg 1994;29:179-185.[Medline]
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Sawin R.S., Conrad E.U., Park J.R., Waldhausen J.H.T. Preresection chemotherapy improves survival for children with Askin tumors. Arch Surg 1996;131:877-880.[Abstract/Free Full Text]
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Cabezali R., Lozano R., Bustamante E., et al. Askin’s tumor of the chest wall: a case report in an adult. J Thorac Cardiovasc Surg 1994;107:960-962.[Free Full Text]
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Bourque M.D., DiLorenzo M., Collin P.P., et al. Malignant small-cell tumor of the thoracopulmonary region (Askin tumor). J Pediatr Surg 1989;24:1079-1083.[Medline]
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Takahashi K., Dambara T., Uekusa T., Nukiwa T., Kira S. Massive chest wall tumor diagnosed as Askin tumor: successful treatment by intensive combined modality therapy in an adult. Chest 1993;104:287-288.[Abstract/Free Full Text]
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A CASE OF PRIMITIVE NEUROECTODERMAL TUMOR (PNET) OF THE CHEST WALL IN AN ADULT
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136(4):
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[Abstract]
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Abstract
Introduction
