Encyclopedia of Pathology

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

Hydrocele Testis

  • Caterina Fattorini
  • Antonio Lopez-Beltran
  • Maria Rosaria RaspolliniEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-28845-1_4826-1



Accumulation of serous fluid between the visceral and parietal layers of the tunica vaginalis (Goldblum et al. 2017).

Clinical Features

  • Incidence

    Fairly common: Together with spermatocele, it affects about 1% of adult male individuals.

  • Age and sex

    Males of any age. Congenital hydroceles result from persistent communication between the tunica vaginalis and the peritoneal cavity. This communication is naturally obliterated usually before the age of 2 years.

  • Site and presentation

    Hydrocele presents as painless scrotal swelling and a feeling of heaviness.

  • Treatment

    In most cases, it disappears on its own. If it does not, surgery may be required.

  • Outcome

    This condition has a benign progress; however, patients need a follow up because hydrocele might recur. Most cases are related to infections and form over time; however, in case of rapid formation of Hydrocele, a neoplasia should be excluded.


Inflated scrotum with serous fluid. In rare cases, the testis may become adherent to the parietal tunica vaginalis, a fact that may clinically mimic a neoplasm. Organizing hemorrhage in a hydrocele may be an additional mimicker of neoplasm, clinically.


Microscopic examination of the hydrocele sac shows features related to a chronic reactive process, including variable chronic inflammation and fibrosis. Mesothelial hyperplasia may also be present, a fact that may occasionally require differential diagnosis with mesothelioma (Fig. 1).
Fig. 1

Reactive mesothelial hyperplasia of the tunica vaginalis


Reactive benign mesothelial cells react with calretinin (nuclear and cytoplasmic), BAP1, and MOC31, while in mesothelioma, cells react with calretinin (nuclear and cytoplasmic) and D2-40, and are negative with BAP1 and MOC31.

Differential Diagnosis

Hydroceles need to be distinguished from solid neoplastic testicular masses, in particular, those with a rapid onset. The cystic or solid nature of the lesion can be easily identified clinically by transillumination.

A rare lesion that may present with enlarging hydrocele is mesothelioma of tunica vaginalis (Chekol and Sun 2012); on ultrasounds, it displays thickening of tunica vaginalis and small papillary projections. A careful microscopic examination and the appropriated immunohistochemical work-up allow the correct diagnosis. Spermatocele should also be ruled out, if this is the case, the cyst develops in the epididymis and contains spermatozoa and proteinaceous fluid.

References and Further Reading

  1. Chekol, S. S., & Sun, C.-C. (2012). Malignant mesothelioma of the tunica vaginalis testis: Diagnostic studies and differential diagnosis. Archives of Pathology & Laboratory Medicine, 136, 113–117.CrossRefGoogle Scholar
  2. Goldblum, J., Lamps, L., McKenney, J., & Myers J. (2017). Rosai and Ackerman’s surgical pathology (11 ed.). Philadelphia: Elsevier.Google Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Caterina Fattorini
    • 1
  • Antonio Lopez-Beltran
    • 2
    • 3
  • Maria Rosaria Raspollini
    • 1
    Email author
  1. 1.Histopathology and Molecular DiagnosticsUniversity Hospital CareggiFlorenceItaly
  2. 2.Pathology Service, Champalimaud Clinical CenterLisbonPortugal
  3. 3.Department of Surgery, Unit of Anatomic PathologyCordoba University Medical SchoolCordobaSpain