Squamous cell carcinoma with sarcomatoid differentiation or carcinosarcoma of the uterine cervix associated with HPV33 infection: report of a rare case

BACKGROUND: Squamous cell carcinoma is the most common malignant tumor of the uterine cervix with a well-documented link to infection with human papillomaviruses (HPV). According to a recent classification, there are several morphological variants of cervical squamous carcinoma, without reference to sarcomatoid squamous cell carcinoma, which is well described in other organs. CASE PRESENTATION: In this paper, we describe an extremely rare case of a 77-year-old woman with primary malignant cervical tumor displaying biphasic histomorphology with an epithelioid and sarcomatoid part; the latter was immunohistochemistry positive for cytokeratin and vimentin. The association with a high-grade squamous intraepithelial lesion and molecular proof of HPV33 infection in the tumor tissue supported our diagnosis of carcinoma with partial sarcomatoid differentiation. CONCLUSION: We report a rare case of a primary cervical epithelial tumor with a partial sarcomatoid phenotype, an unequivocal HPV infection, and an associated precancerous lesion in the cervical mucosa. This is the first description of an HPV33 infection underlying a biphasic epithelioid-sarcomatous tumor of the uterine cervix. The terminology overlap between sarcomatoid carcinoma and carcinosarcoma is also discussed.