Invasive stratified mucin-producing carcinoma of the cervix: A case report and review of the literature.

Invasive stratified mucin-producing carcinoma (ISMC) is a rare, recently described subtype of HPV-associated cervical adenocarcinoma. It shows varied morphological patterns, making it difficult to diagnose, especially the mixed forms. A 57-year-old female, P7L7, presented with postmenopausal bleeding for the past five months. On per-vaginal examination, a friable cervical growth was noted. Microscopic examination of the cervical biopsy showed an invasive tumor composed of nests of stratified columnar cells with peripheral palisading and a variable amount of (alcian blue-positive) intracytoplasmic mucin. Another component of the tumor showed sheets and nests of undifferentiated tumor cells. IHC on both components showed diffuse positivity for P16, PAX8, and keratin 7. Based on these findings, a diagnosis of ISMC was made. Awareness of the morphological features and ancillary stain results of ISMC can aid in picking up the diagnosis in a small biopsy. These findings have prognostic value, as most cases of ISMC behave aggressively.