A 45-year-old woman undergoes surgery for a 15 cm ovarian mass. Histology reveals intestinal-type mucinous epithelium with goblet cells. Pseudomyxoma peritonei is also found at surgery. What is the most important diagnostic step to determine the primary site?
- A Immunohistochemistry for CK7 and CK20
- B Measurement of serum CA-125
- C Appendectomy and thorough examination of the appendix ✓
- D Colonoscopy
Correct answer: C. Appendectomy and thorough examination of the appendix
Explanation
When a mucinous ovarian tumor is found with pseudomyxoma peritonei, the appendix must be examined because appendiceal mucinous neoplasms are the most common primary source that metastasizes to the ovary and mimics a primary ovarian mucinous tumor. Immunohistochemistry can support the diagnosis, but appendectomy and pathological examination of the appendix is the definitive step to exclude an appendiceal primary.
Reference: WHO Classification of Tumours: Female Genital Tumours, 5th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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