Superficial spreading squamous cell carcinoma in situ of the cervix involving the endometrium: a rare case presentation and review of literature.

Objective: Squamous cell carcinoma in situ of the cervix rarely can spread superficially to the inner surface of the uterus replacing the endometrium.

Methods: We report a case of cervical squamous cell carcinoma in situ (CIS) in a 66-year-old female with contiguous extension to the endometrium with small foci of microinvasion. Immunohistochemistry revealed that these tumor cells were positive for p16, p63, and ck5/6 with a high Ki-67 labelling index. It is an extremely unusual phenomenon for cervical CIS superficial to spread to the endometrium.

Conclusions: Cervical CIS can also spread superficially upward, and replace the endometrial lining. The detection of immunohistochemical expression of p16, p63 and CK5/6 in the lesions of cervix and the endometrium suggest that these two lesions are etiologically related, favoring the possibility of the endometrium SCC secondary to cervical SCC in situ, and reveal that HPV is a causative factor for superficial spreading SCC.