Rectal endometriosis mimicking primary rectal adenocarcinoma

Abstract

Endometriosis is a benign entity defined as the presence of endometrium tissue outside of uterine cavity. It is a common disease involving peritoneum, pelvic organs, gastrointestinal tract, and so on. Diagnosis based on cytology specimen can be challenge when we encounter increased cytological atypia in the glandular epithelium, with abundant inflammatory cells and debris in the background. We presented a case of deep rectal endometriosis mimicking rectal adenocarcinoma on cytology specimen and on MRI imaging studies. The combination of endometrial glands, cellular Mullerian stroma, hemorrhage, and hemosiderin-laden macrophages are the characteristic features on cytologic specimens.

Rectovaginal endometriosis with nodular smooth muscle metaplasia diagnosed via transrectal ultrasound‐guided fine‐needle aspiration cytology: An underused minimally invasive diagnostic technique?

“…The presence of cytologic atypia can present a diagnostic pitfall for adenocarcinoma, metastatic neoplasms, and low grade endometrial stromal sarcomas among others. [18][19][20][21][22] The bland-appearing glandular component may be misinterpreted as rectal mucosa while the spindle cell component could be interpreted as rectal smooth muscle sampling or raise the possibility of a smooth muscle neoplasm, especially when the glandular component is minimal or absent. Several benign and malignant neoplasms can present as a pelvic/perirectal mass on imaging and be sampled with TRUS-FNA.…”

“…A deviation of the “classic” cytomorphology includes the presence of epithelial atypia, characterized by nuclear enlargement, crowding, hyperchromasia, and architectural disorganization. The presence of cytologic atypia can present a diagnostic pitfall for adenocarcinoma, metastatic neoplasms, and low grade endometrial stromal sarcomas among others 18–22 …”

Digestive system deep infiltrating endometriosis: What do we know

“…Intestinal endometriosis is often multifocal and multicentric 135 . A tumour‐like appearance can sometimes be misdiagnosed as a malignant tumour of the digestive tract 136 . The malignant aggressiveness of DSIE is associated with collective cell migration (CCM) and EMT 137,138 .…”

“… 135 A tumour‐like appearance can sometimes be misdiagnosed as a malignant tumour of the digestive tract. 136 The malignant aggressiveness of DSIE is associated with collective cell migration (CCM) and EMT. 137 , 138 CCM regulates tissue repair and renewal and participates in cancer spread.…”