Invasive Stratified Mucin-Producing Carcinoma (ISMC) of The Uterine Cervix: A Clinicopathological Study of 8 Cases

Abstract Invasive stratified mucin-producing carcinoma (ISMC) is a rare gynecologic malignancy. Previous studies suggested that ISMC was a morphologic variant of invasive cervical adenocarcinoma. The clinicopathologic features and prognosis of eight cases of ISMC are presented. Clinical symptoms and imaging were atypical. Four cases were pure ISMCs, and four cases were ISMCs mixed with usual-type endocervical adenocarcinomas. The depths of stromal invasion were more than half (5/8), with approximate full-thickness in one case, and there was vascular invasion (5/8), neutral invasion (3/8), uterine segment involvement (3/8), and parametrial involvement (1/8). One of the patients underwent vaginal cuff surgery. Lymph node metastasis was seen in two patients (2/8). All cases were diffusely positive for p16 and high Ki67 expression. These cases had high-risk HPV16,18, 58 infection. All patients were alive after surgery and adjuvant therapy during the 8- to 21-month follow-up, and only one developed vaginal wall recurrence at 15 months. The present data and those obtained from the literature suggest that ISMC is an invasive endocervical adenocarcinoma with high-risk HPV infection, mainly HPV18, and has a risk of recurrence and metastasis.