[Comparison of the clinicopathological features between adenoid basal cell carcinoma and adenoid cystic carcinoma of the cervix].

Objective: To compare the clinical and histopathological characteristics of cervical adenoid basal cell carcinoma and adenoid cystic carcinoma for improving the diagnosis accuracy and differential diagnosis of these tumors. Methods: A retrospective study was conducted on 9 cases of cervical adenoid basal cell carcinoma and 3 cases of adenoid cystic carcinoma which were diagnosed and consulted at the First Medical Center of PLA General Hospital from March 2009 to April 2019. Detailed clinical data were reviewed. All pathological sections and immunohistochemical results were reviewed and the clinicopathological characteristics were analyzed. Follow-up information by telephone was collected and relevant literature was consulted. Results: Both tumors were more commonly found in postmenopausal women (the age of onset ranged 43-74 years). Adenoid basal cell carcinoma was often clinical asymptomatic. Most of them presented as abnormal smears of the cervix during physical examination, and there was no definite mass in colposcopy.Adenoid cystic carcinoma was mostly presented with abnormal vaginal bleeding. A mass was seen in colposcopy.Histologically, the two tumors were characterized by nest-like growth of the tumors, consisting of basal-like tumor cells, and often surrounded by palisade structures. The two lesions might coexist, or be mixed with squamous cell carcinoma or high-grade squamous intraepithelial lesions. The difference was that adenoid basal cell carcinoma was mostly located at the junction of cervical squamous epithelium and columnar epithelium and beneath the overlying epithelium, the tumor cells were arranged in nests, with squamous differentiation in the center of the nests, or in double-layer adenoid arrangement. The cell morphology was bland with occasional mitoses, and the stromal reaction was not obvious. And adenoid cystic carcinoma cells in the nest arranged like a sieve, the homogenous red-stained and blue-stained secretions were observed in the sieve holes, with obvious cell atypia, frequent mitoses, and obvious stromal reaction.In one case of adenoid cystic carcinoma, sarcomatoid area presented around the nests.Both of them were positive in clinical HPV test. Among the 9 cases of adenoid basal cell carcinoma, 3 were tested for HPV and 5 were tested for p16, and all showed positive expression. Among the 3 cases of adenoid cystic carcinoma, 2 were tested for HPV and 3 were tested for p16, both of which showed positive expression. Telephone follow-up was conducted by June 2019(follow-up time ranged 2-37 months). No recurrence or metastasis occurred in 7 of the 9 cases of adenoid basal cell carcinoma, while 1 case had a ground-glass nodule in lung and another had recurrence of vaginal stump 32 months after the surgery.One case of adenoid cystic carcinoma developed lung metastasis 8 months after surgery and died 2 years after surgery; another case was followed up for 6 months, which showed no recurrence or metastasis; the third case was lost to follow-up. Conclusions: Both adenoid cystic carcinoma and adenoid basal cell carcinoma of the cervix are the tumors originating from cervical reserve cells and are associated with high-risk HPV infection. Due to the differences in clinical treatment and prognosis, careful histological evaluation and immunohistochemical analysis should be carried out to make accurate pathological diagnosis.