Carcinoma in situ (CIS) is a distinct pathological entity. The significance of histological variants associated with CIS is not well-understood.

A recent paper published by Sangoi et al. in The American Journal of Surgical Pathology1 described CIS with plasmacytoid features. These features included an abnormal architecture with cellular rounding, enlarged nuclei with eccentric nuclear localization, and dense eosinophilic globular cytoplasm. The authors included 25 urinary bladder biopsies from 23 patients. They evaluated the histology and immune phenotype of the plasmacytoid CIS (P-CIS) specimens.

The authors found that 96% of the cases (23 of 24) stained positive for CK20, 37% (7 of 19) showed abnormal p53 reactivity pattern. CD44 staining was absent in the 63% of the cases (15 of 24) and retained membranous E-cadherin was seen in 100% of cases (18 of 18). During the follow-up period, recurrence or new occurrence of disease was seen in 52% of cases (12 of 23). Of these were the four patients with de novo P- CIS (i.e. no prior or concomitant urothelial neoplasia).

This study sheds light on a rare but important CIS variant. Future studies to define the molecular features and the clinical significance of this variant are needed.

Written by: Bishoy M. Faltas, MD, Director of Bladder Cancer Research, Englander Institute for Precision Medicine, Weill Cornell Medicine

1. Sangoi, Ankur R., Sara M. Falzarano, Marlo Nicolas, and Jesse K. McKenney. “Urothelial Carcinoma In Situ With Plasmacytoid Features: A Clinicopathologic Study of 23 Cases.” The American journal of surgical pathology (2019).

Read the Abstract