A Case of Serous Tubal Intraepithelial Carcinoma Diagnosed by Cytology during the Operation

We experienced a case of serous tubal intraepithelial carcinoma (STIC), which is the earliest morphologically recognizable precursor of pelvic high grade serous carcinoma, diagnosed by cytology during the operation. A 48-year-old Japanese woman visited to our department because of abnormal cytological result and the left adnexal mass on female cancer screening. Pre-operatively, she was diagnosed as cervical intraepithelial neoplasia (CIN) 3, adenomyosis, and the left adnexal cystic lesion with papillary growth. At laparotomy, the left adnexal tumor turned out to be cystic fallopian tube with small papillary growth on the inner surface, but abnormal findings were not present on bilateral ovaries. The cytology of the imprint smears from the papillary projection and ascitic fluid showed positive, suggesting serous adenocarcinoma. Histopathological examination of the lesion revealed the left fallopian tube lesion was STIC with immunohistochemically positive reactivity against p53. No metastases including disseminated lesions were noted. The patient received four courses of systemic chemotherapy, and had no recurrent signs 10 months after the operation.