Encyclopedia of Pathology

Living Edition
| Editors: J.H.J.M. van Krieken

Spermatic Cord Desmoplastic Small Round Cell Tumor

  • Alessandro FranchiEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-28845-1_4944-1

Synonyms

Definition

Desmoplastic small round cell tumor (DSRCT) is a high-grade aggressive round cell tumor of uncertain histogenesis, associated with prominent stromal desmoplasia and polyphenotypic differentiation.

Clinical Features

  • Incidence

    Paratesticular DSRCT is very rare with approximately 20 such cases reported in the literature.

  • Age

    Like DSRCT at other sites, it is seen in older adolescents and young adults.

  • Treatment

    Surgical resection, often with orchiectomy, is the preferred local treatment. Radiotherapy may also be used. Chemotherapy is part of the standard therapy, both in the neoadjuvant and adjuvant setting.

  • Outcome

    The overall survival is poor, ranging between 15% and 30% at 5 years. However, tumors in the paratesticular location have a better survival, possibly because they are detected earlier and they are more amenable to complete surgical resection.

Macroscopy

DSRCT usually appears as a multilobulated or multinodular mass, with a firm cut surface, often with foci of hemorrhage and necrosis.

Microscopy

DSRCT consists of multiple nodules, each composed of nests of uniform round cells with scant cytoplasm, separated by dense bands of collagen (Fig. 1). Areas of necrosis and brisk mitotic activity are usually detected.

Immunophenotype

Immunohistochemically, this tumor is polyphenotypic, staining for vimentin, keratins, EMA, desmin, and NSE. Myogenin, CD99, CD3, CD45, CD20, and inhibin are negative.

Molecular Features

DSRCT is characterized by a recurrent t(11;22) (p13;q12) resulting in the fusion of the Ewing sarcoma gene, EWS, on 22q12 and the Wilms tumor gene, WT1, on 11p13.

Differential Diagnosis

The differential diagnosis of DSRCT is with other small round cell sarcomas, especially Ewing sarcoma/PNET and rhabdomyosarcoma. Diffuse expression of cytokeratins and EMA strongly supports the diagnosis of DSRCT, which in turn usually does not show the diffuse membrane positivity for CD99 seen in Ewing sarcoma/PNET. When considering the differential diagnosis between Ewing sarcoma/PNET and DSRCT, it should be remembered that break apart FISH analysis of EWS gene is not diriment between the two. Rhabdomyosarcoma is positive for myogenin, which is not detected in DSRCT.
Fig. 1

Desmoplastic small round cell tumor consists of sharply demarcated nests of round cells within a desmoplastic stroma

References and Further Reading

  1. Cummings, O. W., Ulbright, T. M., Young, R. H., Dei Tos, A. P., Fletcher, C. D., & Hull, M. T. (1997). Desmoplastic small round cell tumors of the paratesticular region. A report of six cases. The American Journal of Surgical Pathology, 21, 219–225.CrossRefGoogle Scholar
  2. Sedig, L., Geiger, J., Mody, R., & Jasty-Rao, R. (2017). Paratesticular desmoplastic small round cell tumors: A case report and review of the literature. Pediatric Blood & Cancer, 64(12).  https://doi.org/10.1002/pbc.26631.CrossRefGoogle Scholar
  3. Thuret, R., Renaudin, K., Leclere, J., Battisti, S., Bouchot, O., & Theodore, C. (2005). Uncommon malignancies: Case 3. Paratesticular desmoplastic small round-cell tumor. Journal of Clinical Oncology, 23, 6253–6255.CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Department of Translational Research and of New Technologies in Medicine and SurgeryUniversity of PisaPisaItaly