Objectives: Our aim was to review our pathological archive to find out the actual incidence of micropapillary pattern (MPP) in our urothelial carcinoma patient population and determine its correlation with clinical outcome.
Patients and methods: 14 out of 170 cases with complete clinical follow-up were clinicopathologically analyzed. The extent of MPP was determined as tumor percentage.
Results: 12 further cases with MPP were defined in the review. The percentage of patients with positive MPP increased in parallel to the tumor stage. There was no considerable difference between MPP-positive and MPP-negative groups according to the progression rates in non-muscle-invasive and muscle-invasive groups. Progression-free survival was much shorter in MPP cases, but again without statistical significance. Also, there was no significant relation between percentage of MPP and progression-free survival.
Conclusions: Awareness of pathologists about MPP and its highly possible relation with aggressive behavior must be raised, as it may be more common than reported. A multicentric review of a large number of cases with MPP is needed for a better definition of its biological behavior. Focal MPP cases may have a better prognosis but this needs to be confirmed.