Peripheral neuroectodermal tumors

Peripheral neuroectodermal tumors expressing DES, MSA, or MYOGN are classified as polyphenotypic small round cell tumors by many observers. 

Scotlandi K, Serra M, Manara MC, et al. Immunostaining of the p30/32MIG2 antigen and moleculat detection of EWS rearrangements for the diagnosis of Ewing s sarcoma and peripheral neuroectodermal tumor. Hum Pathol. 1996 27 408-416. 

CK, cytokeratin EMA, epithelial membrane antigen LCA, leukocyte common antigen NPC, nasopharyngeal carcinoma ONE, olfactory neuroblastoma ES/PNET, Ewing s sarcoma/peripheral neuroectodermal tumor SNUC, sinonasal undifferentiated carcinoma. 

Many of the tumors of the nasal cavity and paranasal sinuses fall under the category of round cell neoplasms. Among these are olfactory neuroblastoma, sinonasal undifferentiated carcinoma, malignant melanoma, neuroendocrine carcinoma-small cell neuroendocrine carcinoma, malignant lymphoma, extramedullary plasmacytoma, invasive-ectopic pituitary adenoma, rhabdomyosarcoma, and Ewing s sarcoma (ES)-peripheral neuroectodermal tumor (ES/ PNET). But there is also a host of other epithelial lesions that are unique to the sinonasal tract. 

Although the peripheral neuroectodermal tumor (PNET) and ES were first described, respectively, by Stout in 1918 and Ewing in 1921, it has only recently been established through immunohistochemical and genetic-molecular studies that the two are not only related but also belong to the same family of tumors. ES/PNET may be found in bone, soft tissue, and various parenchymal organs (lung, pancreas, kidney), as well as the head and neck. 

Ewing s sarcoma/peripheral neuroectodermal tumor Is composed of uniform round cells with a lobular configuration. 

Askin FB, Perlman EJ. Neuroblastoma and peripheral neuroectodermal tumors. Am J Clin Pathol. 1998 109 S23-S30. 

Rare case reports exist of carcinosarcomas harboring yolk sac tumor " or neuroectodermal elements (including primitive, peripheral neuroectodermal tumor). > When it has been studied, the immunophenotype of these components has been similar to that described in tumors outside the context of carcinosarcoma. 

Thoner, P., Squire, J., Chilton-MacNeil, S. et al (1996) Is the EWS/FLI-1 fusion transcript specific for Ewing s sarcoma and peripheral neuroectodermal tumor AmJ Pathol 148, 1125-1138. 

Ambros, I. M., Ambron, P. F., and Strehl, S. (1991) M1C2 is a specific marker for Ewing s sarcoma and peripheral primitive neuroectodermal tumors. Cancer 67, 1886-1893. 

Fetal fibroblasts myometrium vascular smooth muscle fetal myocardium vascular endothelial cells selected reticulum cells of lymphatic organs some CD30+ lymphoid cells (rarely) selected leiomyosarcomas, epithelioid hemangioendotheliomas, epithelioid angiosarcomas, primitive neuroectodermal tumors and Ewing s sarcomas, malignant peripheral nerve sheath tumors, and clear cell sarcomas... 

Anti-CD99 (M) Dako 1 20 MWER Recognition of virtually all primitive neuroectodermal tumors and Ewing s sarcomas labels roughly 50% of synovial sarcomas and malignant peripheral nerve sheath tumors also present in lymphoblastic lymphomas/ leukemias presenting in soft tissue... 

Eolpe AL, Schmidt RA, Ghapman D, et al. Poorly differentiated synovial sarcoma immunohistochemical distinction from primitive neuroectodermal tumors and high-grade malignant peripheral nerve sheath tumors. Am J Surg Pathol. 1998 22 673-6S2. 

The ability of melanoma to simulate the appearance of various soft tissue sarcomas is also well documented. These include malignant peripheral nerve sheath tumors, gastrointestinal stromal tumors, epithelioid angiosarcoma, rhabdoid tumors, osteosarcomas, and primitive neuroectodermal tumors, to name a few. The detailed immunophenotypic properties of those lesions are provided elsewhere in this book. However, none of them manifests reactivity for gplOO-related melanocytic markers or tyrosinase, making those markers essential to the differential diagnostic process. 

Jones JE, and McGill T. Peripheral primitive neuroectodermal tumors of the head and neck. Arch Otolaryngol Head Neck Surg. 1392 121(12) 1392-1395. 

Dehner LP. Peripheral and central primitive neuroectodermal tumors A nosologic concept seeking a consensus. Arch Pathol Lab Med. E986 EE0 997-E005. 

Banerjee SS, Agbamu DA, Eyden BP, et al. Clinicopathological characteristics of peripheral primitive neuroectodermal tumor of skin and subcutaneous tissue. Histopathology. 1997 31 355-366. 

Lawlor ER, Mathers JA, Bainbridge T, et al. Peripheral primitive neuroectodermal tumors in adults documentation by moleculat analysis./ Clin Oncol. 1998 16 1150-1157. 

Shanfeld RL, Edelman J, Willis JE, et al. Immunohistochemical analysis of neural markers in peripheral primitive neuroectodermal tumors (pPNET) without light microscopic evidence of neural differentiation. Appl Immunohistochem. 1997 5 78-86. 

Kawauchi S, Fukuda T, Miyamoto S, et al. Peripheral primitive neuroectodermal tumor of the ovary confirmed by CD99 immunostaining, karyotypic analysis, and RT-PCR for EWS/FLI-1 chimeric mRNA. Am J Surg Pathol. 1998 22 1417-1422. 

CMV, cytomegalovirus CNS, central nervous system EMA, epithelial membrane antigen GFAP, glial fibrillary acidic protein HV, herpesvirus NF, neurofilament PML, progressive multifocal leukoencephalopathy PNET, primitive neuroectodermal tumor PNS, peripheral nervous system Mw, microwave starting in cold buffer for time noted. 

FIGURE 20.40 This peripheral primitive neuroectodermal tumor (pPNET) is diffusely and intensely positive for MIC2. 

Tsuji, S., Hisaoka, M., Morimitsu, Y. et al (1998) Peripheral primitive neuroectodermal tumor of the lung report of two cases. Histopathology, 33, 396-374. 

Liombart-Bosch, A., Pellin, A., Carda, C. et al (2000) soft tissue Ewing s sarcoma-Peripheral primitive neuroectodermal tumor with atypical dear cell pattern shows type EWS.EEV fusion transcript. Diag Mol Pathol, 9, 137-144. 

Clear Cell Sarcoma of the Kidney 443 Rhahdoid Tumor of the Kidney 443 Juvenile Renal Cell Carcinoma 445 Renal Medullary Carcinoma 446 Malignant Hematologic Diseases 446 Peripheral Primitive Neuroectodermal Tumor 446 Metastases 447... 

Peripheral primitive neuroectodermal tumor (pPNET) of the kidney is a very rare entity with high malignant potential and no specific radiological pattern described. The diagnosis is based on histopathology with subsequent demonstration of typical chromosomal translocations of the PNET/ Ewing tumor family (Doerfler et al. 2001 Vicha et al. 2002 Lam et al. 2003). 

Vicha A, Stejskalova E, Sumerauer D et al (2002) Malignant peripheral primitive neuroectodermal tumor of the kidney. Cancer Genet Cytogenet 139(l) 67-70... 

The Ewing family of tumors comprises small round cell neoplasms of bone and soft tissue that are, in part, defined by a particular chromosomal aberration [t(ll 22)] and variants thereof. Over the past 15 years, it has become clear that ES and peripheral PNET are part of the same spectrum of neoplastic proliferations. Besides the karyotypic marker just mentioned, both of those tumor types also show neuroectodermal features in tissue culture and similarities in proto-oncogene expression. As classically defined, ES was distinguished from PNET by an absence of pseudorosettes and the lack of ultrastructurally or immunohistochemically detectable neuroectodermal features. However, this diagnostic separation is now considered to be antiquated and has been abandoned. 

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