Horm Metab Res 2009; 41(9): 715-719
DOI: 10.1055/s-0029-1238274

© Georg Thieme Verlag KG Stuttgart · New York

Pheochromocytomas, PASS, and Immunohistochemistry

E. Carlsen1 , Z. Abdullah2 , S. M. B. Kazmi2 , G. Kousparos1
  • 1Department of Pathology, Barts and the London NHS Trust, London, UK
  • 2ICMS/Barts School of Medicine and Dentistry, Queen Mary University of London, London, UK
Further Information

Publication History

received 15.12.2008

accepted 11.08.2009

Publication Date:
28 August 2009 (online)


Differentiation between malignant and benign pheochromocytomas of the adrenal gland traditionally relies on the presence of clinically detectable metastases. The PASS system for differentiating between benign and malignant pheochromocytomas is based on defined morphological criteria, of which some are related to tumour cell proliferation and survival. Immunohistochemical markers for important events in the cell cycle were explored in order to characterise differences in apoptosis, G1 checkpoints, and S phase in more detail. A panel consisting of p53, tenascin, bcl-2, pRb, cyclin D1, mcm2, and p27 was employed. Only for pRb a statistically significant difference between PASS 3 and less and PASS 4+ tumours was detected, indicating qualitative differences in the mitotic cycle, probably immediately before early S phase. These results are discussed in relation to similar studies in recent literature.



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