|Year : 2020 | Volume
| Issue : 3 | Page : 127-129
Primary pelvic primitive neuroectodermal tumor: A rare tumor in an adult male
Abhishek Laddha1, Pooja Ashok Phalak2, MR Bindhu2, Appu Thomas1, P Ginil Kumar1
1 Department of Urology, Amrita Institute of Medical Sciences, Kochi, Kerala, India
2 Department of Pathology, Amrita Institute of Medical Sciences, Kochi, Kerala, India
|Date of Submission||04-Mar-2020|
|Date of Acceptance||14-Mar-2020|
|Date of Web Publication||09-Oct-2020|
Dr. Abhishek Laddha
Assistant Professor Urology, Amrita Institute of Medical Sciences and Research Center, AIMS Ponekkara P.O., Kochi - 682 041, Kerala
Source of Support: None, Conflict of Interest: None
Primitive neuroectodermal tumor is a rare tumor involving the genitourinary system. Primary pelvic primitive neuroectodermal tumors are extremely rare in an adult male. We report a case of a young adult with large primary pelvic primitive neuroectodermal tumor.
Keywords: Ewing's sarcoma, pelvic tumor, primitive neuroectodermal tumor
|How to cite this article:|
Laddha A, Phalak PA, Bindhu M R, Thomas A, Kumar P G. Primary pelvic primitive neuroectodermal tumor: A rare tumor in an adult male. Amrita J Med 2020;16:127-9
|How to cite this URL:|
Laddha A, Phalak PA, Bindhu M R, Thomas A, Kumar P G. Primary pelvic primitive neuroectodermal tumor: A rare tumor in an adult male. Amrita J Med [serial online] 2020 [cited 2020 Oct 30];16:127-9. Available from: https://www.ajmonline.org.in/text.asp?2020/16/3/127/297553
| Introduction|| |
Primitive neuroectodermal tumor (PNET) is usually seen in soft tissues or bones in young adults. Primary pelvic PNETs are rare in the pelvic cavity with only a few cases reported so far in female patients. We report a case of large primary pelvic PNET in an adult male.,
| Case Report|| |
A 48-year-old male presented with complaint of one episode of painless gross hematuria with clots. He underwent an MRI of the abdomen for the same and was found to have a large pelvic mass (11.5 cm × 13 cm × 14 cm). All blood investigations were within the normal limits. He underwent a Tru-cut biopsy from the mass, which was suggestive of Ewing sarcoma/PNET. In view of a large mass, he was advised induction chemotherapy with EFT2001 protocol (Vincristine, Ifosfamide, Etoposide VIE/ Vincristine, Actinomycin D (dactinomycin and cyclophosphamide VAC/ Vincristine VCR), (three cycles). He was evaluated again with positron-emission tomography (PET) magnetic resonance imaging (MRI) for response and metastatic evaluation, and PET MRI was suggestive of large pelvic mass, probably arising from the urinary bladder of size 12.5 cm × 11.7 cm with no evidence of metastasis [Figure 1] and [Figure 2]. In view of no radiological response to chemotherapy and mass effects due to bulky tumor, option of surgical resection was preferred over radiotherapy after discussion in tumor board. He was explained the possibility of incomplete resection and positive surgical margins.
|Figure 1: (a and b) Prostate-specific membrane antigen magnetic resonance imaging hybrid scan showing a large pelvic mass|
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|Figure 2: (a) Large pelvic mass displacing urinary bladder with no evidence of distant metastasis (b) heterogeneous enhancement is seen in a pelvic mass|
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He underwent radical cystectomy with excision of the mass and ileal conduit for urinary diversion. Radical cystoprostatectomy was done as mass was not separable from the bladder during the surgery. Final histopathology was suggestive of primary pelvic round blue cell neoplasm, favoring Ewing's/PNET. The diagnosis of primary PENT was made as it involved only serosa of the bladder and prostate. On immunohistochemistry tumor was negative for cytokeratin, epithelial membrane antigen, S-100 desmin, and human leukocyte common antigen (LCA) while it was positive for CD99 and synaptophysin [Figure 3]. In view of poor response to chemotherapy, he underwent further testing with a mutation in Ewing sarcoma breakpoint region 1 (EWSR1) gene, the mutation for which was found in 100% of tumor cells further confirming our diagnosis of Ewing's/PNET. He received three cycles of adjuvant chemotherapy (VAC– Vincristine, ifosfamide and etoposide) 6 weeks after the surgery. The patient is doing well with no evidence of recurrence at 1-year follow-up.
|Figure 3: Pathology images. (a) ×100: showing sheets and nests of tumor cells. (b) ×400: Round cells having scant-to-moderate amount of cytoplasm with round-to-oval nucleus, few showing prominent nucleoli and perivascular rossetoid pattern. (c) Tumor cells are positive for synaptophysin. (d) CD99 shows membranous positivity in tumor cells|
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| Discussion|| |
The common age of the presentation for PNET is around 35 years (90% of tumors are seen in 5–30 years age group) with slight male preponderance., Tumor is primarily seen along the central axis and involves the central nervous system, soft tissue, and bones in children and young adults. Tumor is rarely seen in the kidney, female pelvic organs, testis, prostate, parotid glands pancreas, and adrenal gland. These tumors regardless of an organ of origin are highly aggressive and often develop metastasis to the lung and bone. Five years disease-free survival rate is around 45%–55%. Clinical symptoms are usually vague and depend on either the primary organ of involvement or infiltration of the surrounding organ. In the pelvic cavity, it usually presents with lower urinary tract symptoms with hematuria, changes in bowel habits, or pelvic pain. Some patients may present with constitutional symptoms such as fever or weight loss. Radiology plays an important role in the evaluation of mass as well as planning of further management.
Histologically, tumors may be confused with other small round tumors such as lymphoblastic lymphoma, rhabdomyosarcoma, or poorly differentiated synovial sarcoma. Immunohistochemistry plays an important role in the confirmation of diagnosis, and tumors are usually strongly positive for CD99. Other markers which may be positive are two or more different neural markers (neuron-specific enolase, synaptophysin, S-100, and Vimentin (VIM), neurofilament). Tumors cells are negative for lymphocyte common antigen myoglobin and myosin.
Treatment is usually multimodal. Treatment is usually a combination of early surgical resection with adjuvant chemotherapy or neoadjuvant chemotherapy, followed by surgery or radiation. Usually, tumors respond well to neoadjuvant chemotherapy, followed by surgery or radiation. Common chemotherapeutic agents active against this tumor are vincristine, doxorubicin, ifosfamide, cyclophosphamide, etoposide, and cisplatin. Drug resistance to chemotherapy is common after a few cycles.
Early aggressive surgical resection in resectable cases with the addition of chemotherapy gives the best possible outcome in these aggressive tumors. If tumor is deemed unresectable than neoadjuvant chemotherapy followed by surgery or radiation is viable option. Survival after only chemotherapy is reported in a few case reports but is usually rare. The addition of radiation as adjunct to treatment has been used for incompletely resected tumors as well for unresectable tumors.
| Conclusion|| |
Primary pelvic PNET in an adult male is extremely rare, with no reported cases so far. Pelvic PENT usually presents with symptoms of local infiltration of surrounding organs. Multimodality treatment and surgery in carefully selected patients plays a vital role in the management of these patients. Immunohistochemistry and cytogenetic analysis (EWSR1 gene) helps in making a definitive diagnosis is doubtful cases.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]