Cytology of the fallopian tube: A screening model for high-grade serous carcinoma

Ovarian cancer is a heterogeneous disease having the highest gynecologic fatality in the United States with a 5-year survival rate of 46.5%. Poor overall prognosis is mostly attributed to inadequate screening tools, and the majority of diagnoses occur at late stages of the disease. Due to genetic and biological underpinnings, ovarian high-grade serous carcinomas (HGSC) have etiologic evidence in the distal fallopian tube. Fallopian tube screening modalities are aggressively investigated, but few describe cytological characteristics of benign tubal specimens to help in the comparative detection of HGSC precursor cells. Here, we describe fimbrial cytomorphological and nuclear features of tubal specimens (n = 75) from patients clinically indicated for salpingectomy, bilateral or unilateral salpingo-oophorectomy, and hysterectomies for any diagnosis other than ovarian or peritoneal cancer. Fallopian tube histology was used as the diagnostic reference. A total of 75 samples had benign diagnoses. The benign cytological characteristics of fimbrial tubal specimens included ciliated cells in clustered arrangements with mild nuclear membrane irregularity, mild anisonucleosis, round and/or oval nuclei, hyperchromatic chromatin, and mild nuclear membrane irregularity. In contrast, none of the cytology samples had spindle-shaped nuclei, significantly marked anisonucleosis (n = 1), nor had hypochromasia as a characteristic feature. These cytological characteristics could be a potential area of distinction from HGSC precursor cells. Our study establishes cytomorphological characteristics of nonmalignant tubal cells which help underscore the importance of distinguishing malignant HGSC precursors through fimbrial brush sampling in minimally invasive approach.