Novel treatment of a central type, primitive neuroectodermal tumor of the ovary with postoperative pediatric medulloblastoma chemotherapy regimen: A case report and review of the literature

Primitive neuroectodermal tumors of the ovary: a multidecade review of the scientific literature

Primitive neuroectodermal tumor (PNET) is a general term used in scientific literature for a heterogeneous group of small round-cell malignant tumors primarily arising from neural crest cells. These are extremely aggressive neoplasms which usually occur within soft tissue or bone of young adults. Ovarian tumors composed of primitive neuroectodermal elements are extremely rare, with only few case reports in scientific literature. Due to being so exceedingly rare, PNETs are frequently misdiagnosed and there are no standard therapeutic guidelines. Young patients seem to have better prognoses and individualized strategy is recommended. Limited data suggests that various gene deletions as well as amplifications may be crucial factors for tumorigenesis and the aggressive behavior of PNET. In this paper, we performed a brief review of all cases of primary ovarian PNETs published in the scientific literature to date, in regard to their clinical, histopathological, and therapeutic aspects, with the aim to provide a more comprehensive understanding of this exceedingly rare pathology.

Ovarian Primitive Neuroectodermal Tumor: Are You Central or Peripheral?

Primitive neuroectodermal tumors (PNETs) of the ovary are rare, highly aggressive neoplasms with fewer than 100 cases described. PNETs of the ovary can be classified as either peripheral or central types. The peripheral PNETs have small round cells with or without rosette formation, and the central PNETs can be further delineated based on the CNS tumor they morphologically resemble. We present a case of a central type ovarian PNET in a young female presenting with a pelvic mass and elevated serum tumor markers.

Primitive neuroectodermal tumor of genital tract in hysterectomized patient: A case report

Primitive neuroectodermal tumors are high-grade malignant neoplasms. These are uncommon entities for the female genital tract. The treatment, management and follow-up period of Ewing’s tumors are not well-defined because of their rarity in the genital tract. Surgical debulking is the mainstay treatment in all cases. After debulking surgery, patients receive chemotherapy and/or radiotherapy and there is a relation between disease stage and survival. Herein, we present a case of ovarian primitive neuroectodermal tumor with a review of previously reported cases.

Primitive Neuroectodermal Tumors of the Female Genital Tract: A Morphologic, Immunohistochemical, and Molecular Study of 19 Cases

Primary primitive neuroectodermal tumor (PNET) of the female genital tract is rare, and its proper classification remains unclear. The clinical, histologic, and immunophenotypic features as well as EWSR1 rearrangement status of 19 gynecologic PNETs, including 10 ovarian, 8 uterine, and 1 vulvar tumors, are herein reported. Patient age ranged from 12 to 68 years, with a median age of 20 and 51 years among those with ovarian and uterine PNETs, respectively. Morphologic features of central nervous system (CNS) tumors were seen in 15 PNETs, including 9 medulloblastomas, 3 ependymomas, 2 medulloepitheliomas, and 1 glioblastoma, consistent with central PNET. The remaining 4 PNETs were composed entirely of undifferentiated small round blue cells and were classified as Ewing sarcoma/peripheral PNET. Eight PNETs were associated with another tumor type, including 5 ovarian mature cystic teratomas, 2 endometrial low-grade endometrioid carcinomas, and a uterine carcinosarcoma. By immunohistochemistry, 17 PNETs expressed at least 1 marker of neuronal differentiation, including synaptophysin, NSE, CD56, S100, and chromogranin in 10, 8, 14, 8, and 1 tumors, respectively. GFAP was positive in 4 PNETs, all of which were of central type. Membranous CD99 and nuclear Fli-1 staining was seen in 10 and 16 tumors, respectively, and concurrent expression of both markers was seen in both central and Ewing sarcoma/peripheral PNETs. All tumors expressed vimentin, whereas keratin cocktail (CAM5.2, AE1/AE3) staining was only focally present in 4 PNETs. Fluorescence in situ hybridization was successful in all cases and confirmed EWSR1 rearrangement in 2 of 4 tumors demonstrating morphologic features of Ewing sarcoma/peripheral PNET and concurrent CD99 and Fli-1 expression. In conclusion, central and Ewing sarcoma/peripheral PNETs may be encountered in the female genital tract with central PNETs being more common. Central PNETs show a spectrum of morphologic features that overlaps with CNS tumors but lack EWSR1 rearrangements. GFAP expression supports a morphologic impression of central PNET and is absent in Ewing sarcoma/peripheral PNET. Ewing sarcoma/peripheral PNETs lack morphologic features of CNS tumors.