Ovarian primary primitive neuroectodermal tumor: a review of cases at PUMCH and in the published literature

A Case of Primary Ovarian Primitive Neuroectodermal Tumor

Primitive neuroectodermal tumors (PNET) are a family of poorly differentiated malignant neoplasms of neuroectodermal origin. According to the location of origin, PNETs could be further categorized as central or peripheral. Peripheral PNET (pPNET) is an uncommon type that accounts for 1% of all soft tissue sarcomas and occurs outside the central and sympathetic nervous systems. Ovarian PNET is a very rare tumor with a high mortality rate. We report a case of pPNET originating from the pelvic cavity of a young woman. Ultrasound and Magnetic Resonance Imaging (MRI) findings demonstrated the presence of a high-grade malignant ovarian tumor. On microscopic evaluation, the tumor was composed of solid nests and sheets of small rounded cells, and on Immunohistochemical (IHC) evaluation, the tumor cells showed intense cell-membranous immunoactivity for MIC2 protein (CD99). In the differential diagnosis of any invasive pelvic tumor in young women, pPNET should be considered.

Bilateral primary ovarian Ewing sarcoma recurring as left submandibular lymphadenopathy diagnosed on cytology

Ewing sarcoma (ES) is a highly malignant and aggressive small round-cell tumor originating from primitive neuroepithelium and mesenchymal stem cells. It is usually seen in children and adolescents with a male predilection and a preponderance to occur in long bones. Although skeletal/soft tissue ES is encountered in clinical practice, primary ES of the genital tract, particularly bilateral primary ovarian ES, is highly uncommon, with only a handful of cases reported worldwide. Ovarian ES is occasionally reported to involve para-aortic and pelvic lymph nodes in advanced stages. Still, cervical lymph node metastasis from ovarian ES is an infrequent clinical occurrence and, when present, indicates a worse prognosis. Here, we present an intriguing case of bilateral peripheral primary ovarian ES in an adult female, recurring as metastasis in the left submandibular lymph node. This case underlines the importance of keeping metastasis from ES as a possible differential while diagnosing metastatic small round cell tumors in peripheral lymph nodes. It also highlights the usefulness of a minimally invasive diagnostic modality of fine needle aspiration cytology and cell block preparation with applied ancillary techniques of immunohistochemistry and confirmatory molecular testing by fluorescence in-situ hybridization (FISH), for an accurate and quick diagnosis of such entities. The cytological diagnosis of our patient helped in the prompt and early initiation of chemotherapy without requiring any invasive procedure.

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.

Targeted treatment of refractory primitive neuroectodermal tumor arising from an immature teratoma with crizotinib leading to a sustained response

Here we present a case of metastatic PNET which arose from an immature teratoma that was refractory to standard Ewing sarcoma chemotherapy. This PNET was determined to have elevated levels of ALK protein via IHC. The patient was treated with crizotinib on a palliative basis with a sustained response.

Addressing the diagnostic and therapeutic dilemmas of ovarian immature teratoma: Report from a clinicopathologic consensus conference

Ovarian immature teratoma is a rare subtype of germ cell tumour that can be pure or associated with non-teratomatous germ cell tumour elements and is graded based on extent of the immature neuroectodermal component. Immature teratoma (IT) can also be associated with somatic differentiation in the form of sarcoma, carcinoma, or extensive immature neuroectodermal elements and may produce low levels of serum alpha-fetoprotein. Variable interpretation of these issues underlies diagnostic and management dilemmas, resulting in substantial practice differences between paediatric and adult women with IT. The Malignant Germ Cell International Consortium (MaGIC) convened oncologists, surgeons, and pathologists to address the following crucial clinicopathologic issues related to IT: (1) grading of IT, (2) definition and significance of 'microscopic' yolk sac tumour, (3) transformation to a somatic malignancy, and (4) interpretation of serum tumour biomarkers. This review highlights the discussion, conclusions, and suggested next steps from this clinicopathologic conference.

Extraskeletal Ewing Sarcoma from Head to Toe: Multimodality Imaging Review

Extraskeletal Ewing sarcoma (EES) is a rare subtype in the Ewing sarcoma family of tumors (ESFT), which also includes Ewing sarcoma of bone (ESB) and, more recently, primitive neuroectodermal tumors. Although these tumors often have different manifestations, they are grouped on the basis of common genetic translocation and diagnosis from specific molecular and immunohistochemical features. While the large majority of ESFT cases occur in children and in bones, approximately 25% originate outside the skeleton as EES. Importantly, in the adult population these extraskeletal tumors are more common than ESB. Imaging findings of EES tumors are generally nonspecific, with some variation based on location and the tissues involved. A large tumor with central necrosis that does not cross the midline is typical. Despite often nonspecific findings, imaging plays an important role in the evaluation and management of ESFT, with MRI frequently the preferred imaging modality for primary tumor assessment and local staging. Chest CT and fluorine 18 fluorodeoxyglucose PET/CT are most sensitive for detecting lung and other distant or nodal metastases. Management often involves chemotherapy with local surgical excision, when possible. A multidisciplinary treatment approach should be used given the propensity for large tumor size and local invasion, which can make resection difficult. Despite limited data, outcomes are similar to those of other ESFT cases, with 5-year survival exceeding 80%. However, with metastatic disease, the long-term prognosis is poor. ^©RSNA, 2022.

Primary uterine Ewing sarcoma - A case report

OBJECTIVE

Ewing sarcoma is a type of neuroectodermal tumors (Ewing family of tumors-EFT) that mostly affect the bone or soft tissue. Primary uterine Ewing sarcoma is extremely rare.

CASE REPORT

We report a case of a primary uterine Ewing sarcoma in a 46-year-old patient, treated with total abdominal hysterectomy, and bilateral salpingo-oophorectomy and following adjuvant chemotherapy with 6 cycles of vincristine, doxorubicin, and cyclophosphamide, achieving complete remission for one year.

CONCLUSION

Complete resection for EFT is the first choice of treatment, regardless of their origins. Adjuvant chemotherapy or radiotherapy is mandatory if needed. Due to rarity of the disease, this report re-emphasizes the accurate diagnosis and appropriate treatment for these unusual tumor types occurred in female genital organs.

18F-FDG PET/CT for Staging and Response Evaluation in a Rare Case of Childhood Ovarian Primitive Neuroectodermal Tumor

ABSTRACT

Primitive neuroectodermal tumor (PNET) is an aggressive small cell malignancy. Apart from the central nervous system, they can arise from peripheral sites as well. Ovarian PNETs are extremely rare neoplasms. We here present a case of childhood ovarian PNET, where 18F-FDG PET/CT was efficiently used for staging and response evaluation.

Giant primitive neuroectodermal pelvic tumour: a case report and literature review

Primitive neuroectodermal tumours (PNETs) are rare malignant small round cell tumours. Notably, despite widespread reports of PNET in multiple parts of the body, it is extremely rare in the pelvis. Here, a rare case of giant PNET of the pelvis, that was treated with surgical intervention comprising hemipelvectomy and amputation, is reported. A 42-year-old female patient presented with an enlarged mass on the left hip and severe pain in the left lower extremity for the previous 6 months. Preoperative imaging examinations indicated an irregular soft tissue-like signal shadow sized 19 × 15 × 12 cm at the left ilium and sacrum. After surgical intervention involving left hemipelvectomy and amputation, the tumour was diagnosed by pathology as PNET. During the courses of postoperative radiotherapy and chemotherapy, local recurrence and distant metastasis occurred, and the patient died 9 months following surgical treatment. To the best of the authors' knowledge, the current case is the largest pelvic PNET resection reported to date. Pelvic PNET is extremely malignant and has a high mortality rate regardless of surgical treatment, however, surgical resection of the lesion may relieve the symptoms, extend life, and improve quality of life to a certain extent.

Ewing Sarcoma With Emphasis on Extra-skeletal Ewing Sarcoma: A Decade's Experience From a Single Centre in India

INTRODUCTION

The diagnosis of Ewing sarcoma family of tumours (ESFT) is challenging, especially in adults and in extra-skeletal or visceral location. Several morphologic mimics with varied treatment options and prognosis confer diagnostic dilemmas. Application of ancillary diagnostic modalities in surgical pathology in clinical routine has enabled accurate diagnosis of ESFT in bone, soft tissues, and viscera.

AIM

The study aims to assess the clinicopathological features including molecular test results of ESFT with emphasis on sex, age, and location, especially extra-skeletal soft tissue and visceral location.

MATERIAL AND METHODS

Data of clinicopathological, molecular tests (wherever performed), diagnosis rendered in 302 ESFT over a decade from our centre were reviewed. Statistical comparison of skeletal and extra-skeletal tumours with reference to age and sex was done using SPSS package. The P value of <.05 was considered significant.

RESULTS

The cohort included 302 ESFTs with 49% skeletal and 51% extra-skeletal tumours. Thigh was most common site among skeletal tumours; chest wall, paraspinal location, and retroperitoneum among soft tissues (39.4%); and kidney, ovary, and cervix among visceral tumours (11.3%). Fluorescence in situ hybridisation for EWSR1 gene rearrangement was positive in 54 patients and reverse-transcriptase polymerase chain reaction in 19 patients. Predominance of male sex, younger age and location in extremities among skeletal tumours and lack of gender predilection, higher age and axial location in extra-skeletal tumours were noted, which were statistically significant. Molecular tests were performed more frequently in extra-skeletal tumours, especially in visceral tumours to establish the diagnosis.

CONCLUSIONS

The study showed statistically significant differences in the age, sex, and location between skeletal and extra-skeletal ESFT. The increased percentage of extra-skeletal tumours especially in viscera was attributed to the increased awareness and availability of ancillary techniques.