Occult cervical microinvasive squamous cell carcinoma with superficial endometrial spread mimicking high-grade squamous intraepithelial lesion in a postmenopausal woman: a case report.

BACKGROUND

Superficial spreading squamous cell carcinoma (SSSCC) of the cervix with endometrial extension is rarely observed in postmenopausal women. Cervical atrophy may reduce the diagnostic accuracy of colposcopy and conization for this condition. We report a case of a subtle microinvasive cervical squamous cell carcinoma with extensive endometrial spread initially misdiagnosed as a high-grade squamous intraepithelial lesion (HSIL) during conization.

CASE PRESENTATION: We report the case of a 56-year-old postmenopausal woman who was referred after high-risk human papillomavirus positivity and cytology showing atypical squamous cells that could not rule out a high-grade lesion. Colposcopy-directed biopsy and subsequent deep cervical conization showed a high-grade squamous intraepithelial lesion/cervical intraepithelial neoplasia (CIN) grade 3 with glandular involvement, without definite invasive carcinoma. Since residual disease was suspected, she had an extrafascial total hysterectomy (ETH) with bilateral salpingo-oophorectomy. The frozen section revealed squamous neoplasia involving the endometrium. Final pathology showed a cervical high-grade squamous intraepithelial lesion with a microinvasive squamous cell carcinoma focus of less than 0.5 mm, no lymphovascular space invasion (LVSI), superficial spread into the endometrium, and focal superficial invasion. Immunohistochemistry (IHC) showed diffuse block-type p16 positivity, p40 positivity, and negativity for PAX8, estrogen receptor (ER), and progesterone receptor (PR), supporting a cervical origin rather than a primary endometrial squamous cell carcinoma. At 6 months, the patient was disease-free, tested negative for human papillomavirus, and had no intraepithelial lesion or malignancy on cytology.

CONCLUSION

This case highlights that conization may underestimate occult invasive disease in postmenopausal women with cervical atrophy and glandular involvement. When endometrial squamous lesions are found, superficial spreading cervical squamous neoplasia should be considered, and immunohistochemistry should be performed to distinguish secondary endometrial involvement from primary endometrial disease. For carefully selected stage IA1 lesions without lymphovascular space invasion, extrafascial total hysterectomy can be a definitive treatment option.