Urothelial carcinoma involving vaginal specimens from patients with neobladder: A potential pitfall in diagnostic cytopathology

Abstract

Most vaginal neoplasms represent metastasis from the cervix, endometrium, colon and ovary and distinction from a primary lesion does not pose a diagnostic problem. Recently, it has been recognized that women with urothelial carcinoma (UC) who have undergone radical cystectomy with orthotopic neobladder reconstruction are at risk for recurrence in the lower gynecologic tract. Our objective is to describe the cytologic features of cases with confirmed UC in the vagina in this clinical setting. Four vaginal specimens from patients with prior radical cystectomy and orthotopic neobladder reconstruction with histologically confirmed UC were evaluated. The vaginal specimens consisted of Thinprep® and Papanicolaou-stained slides. Cytomorphologic parameters including cellular arrangement, cell size and shape, cytoplasm, and nuclear features were evaluated and compared with a corresponding surgical biopsy. All four cases were highly cellular with abundant neoplastic cells arranged singly and in loose three-dimensional clusters with overlapping nuclei. The neoplastic cells were large and polygonal with well-defined cell borders, high nuclear to cytoplasmic ratio, and granular basophilic cytoplasm. The chromatin was coarse with small nucleoli. Scattered keratinized single cells with atypical hyperchromatic nuclei were observed in each case. In summary, UC involving the vagina can share many morphologic features with primary squamous cell carcinomas at this site, including focal keratinization. Abundant three dimensional clusters of neoplastic cells and a previous history of orthotopic neobladder reconstruction are helpful cytomorphologic and clinical features supporting a diagnosis of UC involving the vagina and may prevent unnecessary work-up for a new primary lesion.