GPR: 2021 - Week 19

From MGH Learn Pathology

Clinical history

31F with abdominal pain and hematochezia, found to have a sigmoid colon polypoid mass (pictured):


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Polypoid endometriosis
  • Implantation of endometrial glands/stroma with formation of polypoid pink/gray/tan masses
  • Microscopically, glandular component can have simple-complex hyperplasia with atypia
  • Stromal component lacks hypercellularity, atypia - helps to distinguish from adenosarcoma
  • Colon, ovary, uterine serosa, cervical/vaginal mucosa are most common sites




  • Polypoid, spongy mass(es), occasionally with internal cavitation
  • Can present as uterine or extrauterine tumors
  • Extrauterine presentation can simulate endometriosis; frequently disseminated at diagnosis
  • Microscopically characterized by stromal hypercellularity, atypia, and increased mitotic activity
  • Periglandular stromal condensation ("cuffing") is common



Colorectal adenocarcinoma

  • More typically a single mass lesion with raised edges and central ulceration, often with "apple-core" circumferential narrowing of lumen
  • Growth patterns are variably circumscribed, infiltrative, or budding
  • Stromal desmoplasia but not atypia.

Drs Oliva, Young, Zukerberg
  • Parker, Dadmanesh, Young, Clement. "Polypoid endometriosis: a clinicopathologic analysis of 24 cases and review of the literature." Am J Surg Pathol, 2004.
  • Oliva, E. "Endometrial Stromal Tumors, Mixed Müllerian Tumors, Adenomyosis, Adenomyomas and Rare Sarcomas" Robboy's pathology of the female genital tract. 3rd edition.
  • Kurman, Ellenson, Ronnett. "Blaustein's pathology of the female genital tract" 6th edition. Springer.

This week's Gross Pathology Roundup was presented by Christopher Mount MD, PhD on 2021-05-10.