Histologic characterization of uterine papillary serous adenocarcinoma

Uterine papillary serous adenocarcinoma (UPSC) is one of the most aggressive endometrial tumors. UPSC has been associated with an increased propensity for extrauterine spread. Survival rates of not more than 50% are commonly reported even for tumors which appear to be confined to the uterus. Small areas of UPSC can be found in otherwise well-differentiated endometrial lesions and yet still determine the overall prognosis. In the present study we evaluated histologic criteria that might be helpful in diagnosing small-volume UPSC, including silver-stained nucleolar organizer regions (AgNOR) which have prognostic importance in a variety of tumors, and nuclear size which has been used for prognostication in endometrial cancer. We examined 25 UPSC specimens and compared them to grade III (GIII, n = 10) and grade I (GI, n = 10) typical endometrial adenocarcinoma using the following parameters: mean AgNOR count per cell was UPSC 6, GIII 6.0, and GI 4.3; mean AgNOR area was UPSC 1.28 μm², GIII 1.35 μm², and GI 0.86 μm²; total AgNOR area per cell was UPSC 7.5 μm², GIII 8.13 μm², GI 4.47 μm²; and nuclear size was UPSC 66.9 μm², GIII 60.3 μm², GI 34.8 μm². All differences between UPSC or GIII tumors and GI lesions were statistically significant. Overexpression of p53, as determined histochemically, was seen in 64% of the UPSC specimens. UPSC is characterized by high AgNOR count and area per cell, large nuclear size, and a high rate of p53 overexpression. Evaluation of these parameters in biopsy material may aid in selecting high-risk patients for adjuvant therapy trials.