Invasive stratified mucin-producing carcinoma. A case series with associated pathological findings

Abstract

Background: Stratified mucin producing intraepithelial lesion (SMILE) is associated with high risk HPV carcinogenesis and morphologically overlaps with cervical intraepithelial neoplasia (CIN) and adenocarcinoma in situ (AIS). In 2016, Schoolmeester et al.1 described a case series of SMILE in which they observed unambiguous invasive adenocarcinomas resembling SMILE and proposed the term ‘invasive SMILE’ for such lesions. Aims: To describe a case series of a recently named group of endocervical adenocarcinomas. Methods: A retrospective search of the practice records was performed using the last year of records. Eight cases were identified, 3 of which had a component of invasive carcinoma resembling SMILE. Results: We identified 3 cases of invasive SMILE and described their pathological features. Discussion: All cases showed cytologically bland nuclear features and distinct palisading. Mitotic figures and apoptosis were easily identified in all 3 cases. 2 out of 3 cases were mucin rich and showed a neutrophilic infiltrate. One case was mucin poor and lacked a neutrophilic infiltrate. We found co-existent CIN in 66% of cases and ACIS in 33% of cases. There are clear morphological and immunohistochemical features supporting the designation of invasive SMILE as a distinct entity in the spectrum of cervical neoplasias. Reference1.Lastra R, Park J, Schoolmeester K. Invasive stratified mucin-producing carcinoma and stratified mucin-producing intraepithelial lesion (SMILE): 15 cases presenting a spectrum of cervical neoplasia with description of a distinctive variant of invasive adenocarcinoma. Am J Surg Pathol 2016; 40: 262–9.