We present the case of a 55‐year‐old asymptomatic woman in whom a left adnexal mass was incidentally discovered during a routine ultrasound examination. PET/CT imaging revealed a hypermetabolic left abdominopelvic mass measuring 25 cm in diameter and a 3‐cm lesion located in the pancreatic tail. Histologically, a focal mucinous component with intestinal‐type epithelium was identified instead of endocervical tissue. Immunohistochemically, there was aberrant overexpression of p53, diffuse CK7 positivity, focal CK20 and CDX2 expressions, and absence of PAX8. These findings supported a diagnosis of metastatic pancreatic ductal adenocarcinoma rather than a gynecologic carcinoma of serous tubal intraepithelial carcinoma (STIC) origin, which can mimic this pattern due to intraepithelial spread in the fallopian tube. We emphasize the need for caution in patients presenting with pelvic masses and histology suggestive of adenocarcinoma associated with STIC. An interdisciplinary approach and comprehensive diagnostic evaluation are crucial for establishing the correct diagnosis, which is essential for appropriate treatment planning and patient prognosis.
Valle et al. (Thu,) studied this question.