PRIMITIVE NEUROECTODERMAL TUMOR OF THE SPERMATIC CORD

HIROAKI MATSUMOTO, RYO INOUE, MASAHIRO TSUCHIDA, MUTSUO TAKAHASHI AND

KATSUSUKE NAITOFrom the Department of Urology and First Department of Pathology, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan

KEY WORDS: neuroectodermal tumors, primitive; genital neoplasms, male; spermatic cord; therapy, combination drug

Primitive neuroectodermal tumor (PNET) originates fromneural crest cells and is classified into the group of smallround cell tumors with high morbidity and mortality. PNETis also a member of the family of Ewing tumors, which in-clude Ewing’s sarcoma, peripheral neuroepithelioma andAskin tumor.1 These tumors typically develop in children andarise from the central nervous system, lungs and soft tissues.We report a case of PNET arising from the spermatic cordthat was treated with resection and chemoradiotherapy.

CASE REPORT

A 53-year-old man presented with a recurrent left inguinalmass, which had originally been resected by another surgeon.At the previous operation the nature of the tumor was un-clear on routine pathological examination. The patient had apalpable mass measuring approximately 7 cm. that extendedfrom the left inguinal region to the scrotum.

Abdomino-pelvic computerized tomography revealed a ho-mogeneous solid mass measuring 2.4 � 2.7 � 7 cm. that wasrelated to the left spermatic cord. On magnetic resonanceimaging the mass demonstrated hypointensity on T1-weighted images and hyperintensity on T2-weighted images

(fig. 1, A). Tumor markers were negative for �-fetoprotein,carcinoembryonic antigen, �-human chorionic gonadotropin,and neuron specific enolase. No metastases were detected.

Preoperative workup was done and informed consent wasobtained. Left radical orchiectomy with complete excision ofthe mass was performed. The tumor was adherent to thespermatic cord, but was easily separated from the muscletissue and pubic bone. The lesion was firm and had a whitishcut face (fig. 1, B).

Histological examination revealed the monotonous prolif-eration of small round cells (fig. 2, A). Immunohistochemicalstaining was nonspecific and was negative for CD99, which isoften positive in tumors of the Ewing’s sarcoma family. How-ever, staining for S-100 protein was positive, CD56 was pos-itive and FLI1 gene product was weakly positive. Electronmicroscopy showed primitive cells with neurosecretory gran-ules in the cytoplasm (fig. 2, B), indicating neuronal differ-entiation and confirming the diagnosis of PNET. We did notdetect EWS-FLI1 or EWS-ERG fusion gene transcripts intumor tissue using the reverse transcription polymerasechain reaction method.

Postoperatively, the patient received 2 cycles of adjuvantchemotherapy using the CyVADIC protocol2 (cyclophospha-

Accepted for publication November 21, 2001.

FIG. 1. A, magnetic resonance imaging shows hyperintense tumorin left scrotum on T2-weighted image. B, resected testis and sper-matic cord with tumor involvement.

FIG. 2. A, microscopic appearance of PNET. Note monotonous pat-tern of undifferentiated small round cells. H & E, reduced from�200. B, electron microscopy reveals primitive cells have neurose-cretory granules in cytoplasm (arrow).

0022-5347/02/1674-1791/0THE JOURNAL OF UROLOGY® Vol. 167, 1791–1792, April 2002Copyright © 2002 by AMERICAN UROLOGICAL ASSOCIATION, INC.® Printed in U.S.A.

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mide 500 mg./m.2, vincristine 1.5 mg./m.2, doxorubicin 50mg./m.2 and dacarbazine 250 mg./m.2) simultaneously withirradiation (25.2 Gy.) to the left inguinal region. The patientwas without evidence of recurrence at 8 months followingsurgery.

DISCUSSION

PNET is a well-known tumor of childhood, but genitouri-nary involvement in adults is rare. To our knowledge this isthe first case of a primary spermatic cord tumor. This diseaseusually shows rapid progression and infiltration into sur-rounding tissues, so PNET is often treated with adjuvantchemotherapy or radiation therapy. Our patient had a recur-rent tumor that showed rapid progression, so we performedradical resection and administered adjuvant chemotherapy(the CyVADIC protocol2) plus radiation therapy.

Recently, molecular and cytogenetic analysis of PNET andthe Ewing’s sarcoma family of tumors has been performed.These tumors are best characterized by the expression ofchimeric genes that represent fusion of the EWS gene on22q12 with ETS family genes translocated from 11q24. In

85% of patients the FLI1 gene is involved in 11q24 translo-cation, while in 15% it shows variant or complex transloca-tion.3 Although our case did not demonstrate expression ofEWS-FLI1 or EWS-ERG chimeric mRNA, we might havedetected another variant or complex translocation by per-forming appropriate investigations.

In conclusion, with this type of tumor several differenttools may be needed to make a precise diagnosis, and aggres-sive combination therapy is required for a favorable progno-sis.

REFERENCES

1. Dehner, L. P.: Primitive neuroectodermal tumor and Ewing’ssarcoma. Am J Surg Pathol, 17: 1, 1993

2. Pinedo, H. M., Bramwell, V. H. C., Mouridsen, H. T. et al:Cyvadic in advanced soft tissue sarcoma: a randomized studycomparing two schedules. A study of the EORTC Soft Tissueand Bone Sarcoma Group. Cancer, 53: 1825, 1984

3. Giovannini, M., Biegel, J. A., Serra, M. et al: EWS-erg andEWS-Fli1 fusion transcripts in Ewing’s sarcoma and primitiveneuroectodermal tumors with variant translocations. J ClinInvest, 94: 489, 1994

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