Encyclopedia of Pathology

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

Perivascular Epithelioid Cell Tumor

  • Maria Rosaria RaspolliniEmail author
  • Antonio Lopez-Beltran
Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-28845-1_4895-1



It is a neoplasm with smooth muscle and melanocytic differentiation which arises from perivascular epithelioid cells.

Clinical Features

  • Incidence

    Very uncommon tumors. No association with tuberous sclerosis

  • Age

    Most reported cases between 19 and 48 years

  • Sex

    No sex predilection

  • Site

    Most cases arise in the kidney (angiomyolipoma) that should be described elsewhere, but with anecdotal cases described in the bladder or prostate (Martignoni et al. 2015).

  • Treatment


  • Outcome

    The majority of the cases have shown a benign course with only a few malignant cases with metastatic disease.


PEComa shows typically a solid well-circumscribed or infiltrative tumor with a size range of 0.5–9 cm in greatest dimension.


The tumor may show two patterns, epithelioid and spindled, with one dominant pattern. Epithelioid pattern is arranged in nests and spindled pattern in fascicles. The epithelioid component is associated with blood vessel. Tumor cells show clear or eosinophilic cytoplasm. The tumor involves the bladder wall, and the covering urothelium is unremarkable (Fig. 1); in the prostate gland, the tumor is surrounded by normal appearing glands. Necrosis may be present, a finding related to malignant behavior in one case (Pan et al. 2003; Weinreb et al. 2007; Sukov et al. 2009).


Tumor cells stain with melanocytic markers HMB45 (Fig. 2) and MART1, muscle-specific actin, tyrosinase, cathepsin K, and TFE3.

Molecular Features

TFE3 gene rearrangement has been reported (Williamson et al. 2013).

Differential Diagnosis

Differential diagnosis includes urothelial carcinoma (positive for epithelial markers), paraganglioma (PS100 positive), epithelioid leiomyosarcoma (positive for smooth muscle lineage markers), and inflammatory myofibroblastic tumor (different histologic appearance and ALK positive). The immunohistochemical stainings are helpful to achieve the correct diagnosis.
Fig. 1

PEComa involving the bladder wall with unremarkable covering urothelium. Hematossilin-eosin stain 4X

Fig. 2

Epithelioid cells: hematossilin-eosin stain 20X (a) and HMB45 stain (b)

References and Further Reading

  1. Martignoni, G., Pea, M., Zampini, C., et al. (2015). PEComa of the kidney and of genitourinary tract. Seminars in Diagnostic Pathology, 32, 140–159.CrossRefGoogle Scholar
  2. Pan, C.-C., Yu, I. T., Yang, A.-H., et al. (2003). Clear cell myomelanocytic tumor of the urinary bladder. The American Journal of Surgical Pathology, 27, 689–692.CrossRefGoogle Scholar
  3. Sukov, W. R., Cheville, J. C., Amin, M. B., et al. (2009). Perivascular epithelioid cell tumor (PEComa) of the urinary bladder: Report of 3 cases and review of the literature. The American Journal of Surgical Pathology, 33, 304–308.CrossRefGoogle Scholar
  4. Weinreb, I., Howarth, D., Latta, E., et al. (2007). Perivascular epithelioid cell neoplasm (PEComas): Four malignant cases expanding the histopathological spectrum and a description of a unique findings. Virchows Archiv, 450, 463–470.CrossRefGoogle Scholar
  5. Williamson, S. R., Bunde, P. J., Montironi, R., & Lopez-Beltran, A. (2013). Malignant perivascular epithelioid cell neoplasm (PEComa) of the urinary bladder with TFE3 gene rearrangement: Clinicopathologic, immunohistochemical, and molecular features. The American Journal of Surgical Pathology, 37, 1619–1626.CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

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