Collagen Balls in Cervical Smears: A Previously Undescribed Finding

OBJECTIVE: To evaluate several conventional cervical smears obtained from women undergoing routine screening for cervical dysplasia or carcinoma and whose smears contained structures resembling collagen balls. STUDY DESIGN: Between 1995 and 1998, cervical smears containing collagen balls were analyzed. The clinical histories of the patients whose smears contained collagen balls, including the gestational history, were reviewed. Histopathologic material from any related surgical specimens was reviewed, with special attention to mesothelial surfaces. RESULTS: Collagen balls were found in 5 of 77,891 Pap smears examined (0.006%). None of the patients had evidence of neoplasms of the genital tract. One of the patients was in the first trimester of pregnancy. CONCLUSION: We suggest that collagen balls in cervical smear originate in mesothelium-covered organs, from where they are transported via the fallopian tubes into the uterine cavity. Their significance lies in their being mistaken for mucin-distended cells exfoliated from a neoplasm or from detached fragments of a papillary ovarian neoplasm.