Role of Pap Smear Cervical Cytology in the Diagnosis of Extrauterine Malignancies: Largest Study of 104 Cases from Tertiary Care Cancer Centre in India.

Introduction: Extrauterine malignancies in cervical samples are rarely seen. It is important to differentiate these cells from those of primary uterine malignancies to determine appropriate line of further investigations and management. Literature on these lesions is limited largely restricted to case reports. The aim of the present study was to study the spectrum and cytomorphological features of extrauterine malignancies in cervical Pap smears.

Materials and methods: It is a retrospective and descriptive study conducted in Department of Cytopathology from January 2019 to July 2023. All cases of extrauterine malignancies with available cytology material were included in this study. All cases of primary uterine malignancies, i.e., uterine corpus or cervix confirmed by clinical, radiological, and histopathological examination were excluded.

Results: 104 out of 11,674 cytology Pap smears were those of extrauterine malignancy. Diagnosis of extrauterine malignancy was given in 47.1% cases, 30.9% were reported as positive for malignancy without giving the possibility of an extrauterine origin, and 22.0% were reported as atypical glandular cells only. In 56 cases where Pap smear was the first investigation which led to the diagnosis. Most common extrauterine malignancy was adenocarcinoma principally from ovarian, colorectal, and vaginal origin. Other epithelial malignancies noted were urothelial carcinoma and invasive breast carcinoma. Among non-epithelial malignancies, we reported vaginal mucosal melanoma, cutaneous melanoma, acute leukaemia, and anaplastic large cell lymphoma.

Conclusion: High index of suspicion, presence of squamous and glandular elements with no atypical features, and occasional clusters of cells with marked atypia and usually no necrosis in the background are helpful cytomorphological clues to raise suspicion for extrauterine malignancy. Correlation with serology, radiology, and immunocytochemistry can help in reaching final diagnosis.