Cytologic Features of Uterine Papillary Serous Carcinoma 95 Fig. 3. Cervicovaginal smear of uterine papillary carcinoma shows a papillary cluster and single scattered malignant cells in back- ground of tumor diathesis and lysed blood (Papanicolaou stain, ×400). Table 2. Clinicopathological features of uterine papillary serous carcinoma Parameters Age (mean, yr) Cervicovaginal cytology (n=12) Histologic findings (n=8) Myometrial invasion Cervical invasion Lymphovascular involvement Regional lymph nodes* involvement Adnexal involvement Peritoneal cytology (n=8) FIGO stages (n=8) Results No. of cases (%) 44-67 (56.2) Benign cellular change 2 (16.7) AGC 1 (8.3) Adenocarcinoma 8 (66.7) Adenocarcinoma and HSIL 1 (8.3) Less than one-half More than one-half Positve Negative Positive Negative Positive Negative Positive Negative PFMC NFMC Stage I Stage II Stage III 2 (25) 6 (75) 4 (50) 4 (50) 6 (75) 2 (25) 3 (37.5) 5 (62.5) 2 (25) 6 (75) 1 (12.5) 7 (87.5) 3 (37.5) 2 (25) 3 (37.5) AGC, atypical glandular cells; HSIL, high-grade squamous intraepithe- lial lesion; PFMC, positive for malignant cells; NFMC, negative for malig- nant cells; FIGO, international federation for gynecology and obstetrics. *Regional lymph nodes are the pelvic and the para-aortic nodes. highly malignant-appearing nuclei arranged in sheet-like groups. Single cells with dense basophilic or eosinophilic cyto- Fig. 4. Histology of uterine papillary serous carcinoma shows short and dense papillae. The cells covering the papillae and lining glands form small papillary tufts or floating clusters (H&E stain, ×100). Tumor cells reveal dense eosinophilic cytoplasm with high grade nulclear atypia (inset, H&E stain, ×400). plasm resembling atypical squamous cells were frequently present. Histologically, this case revealed both UPSC and invasive squamous cell carcinoma in the endometrium and the cervix, respectively. Each of the 12 cases was histologically diagnosed as papil- lary serous carcinoma. The tumors revealed many short and fibrotic or thin and delicate papillae. The cells covering the papillae and lining glands formed small papillary tufts or float- ing clusters (Fig. 4). These cells showed high-grade nuclear atypia and often contained a macronucleoli. Slides from hys- terectomy specimens were available for review for eight of the patients; only two cases (25%) revealed that the carcino- ma invaded less than one half of the myometrium, while six cases (75%) revealed a deep invasion of more than one half of the myometrium. Four (50%) cases revealed cervical involve- ment by the tumor. Three of the four patients with cervical involvement had positive cervicovaginal smears. Six of the eight cases (75%) revealed lymphovascular tumor invasion. Histologically documented metastases to regional lymph nodes were present in three cases (37.5%). Only a single case (12.5%) had malignant cells in the peritoneal washing fluid (Table 2). DISCUSSION UPSC is a histologically distinct variant of endometrial ade- nocarcinoma that accounts for approximately 10% of endome- trial glandular tumors (5). UPSC is biologically aggressive and is associated with deep myometrial invasion, vascular invasion,