abstract: Unusual DNA mismatch repair-deficient tumors in Lynch syndrome: a report of new cases and review of the literature.

Unusual DNA mismatch repair-deficient tumors in Lynch syndrome: a report of new cases and review of the literature.

Hum Pathol. 2012 Apr 17;


Abstract

Immunohistochemical detection of DNA mismatch repair proteins and polymerase chain reaction detection of microsatellite instability have enhanced the recognition of mismatch repair-deficient neoplasms in patients with Lynch syndrome and, consequently, led to the identification of tumors that have not been included in the currently known Lynch syndrome tumor spectrum.

Here, we report 4 such unusual tumors. Three of the 4, a peritoneal mesothelioma, a pancreatic acinar cell carcinoma, and a pancreatic well-differentiated neuroendocrine tumor, represented tumor types that, to the best of our knowledge, have not been previously reported in Lynch syndrome. The fourth tumor was an adrenocortical carcinoma, which has rarely been reported previously in Lynch syndrome. Three of our 4 patients carried a pathogenic germ-line mutation in a mismatch repair gene. The unusual tumor in each of the 3 patients showed loss of the mismatch repair protein corresponding to the mutation. The fourth patient did not have mutation information but had a history of colonic and endometrial carcinomas; both lacked MSH2 and MSH6 proteins. Interestingly, none of the 4 unusual tumors revealed microsatellite instability on polymerase chain reaction testing, whereas an appendiceal carcinoma from 1 of the study patients who was tested simultaneously did. The recognition of such tumors expands the repertoire of usable test samples for the workup of high-risk families.

As yet, however, there are no data to support the inclusion of these tumors into general screening guidelines for detecting Lynch syndrome, nor are there data to warrant surveillance for these tumors in patients with Lynch syndrome.

Mucinous Tumors of the Ovary: Diagnostic Challenges at Frozen Section and Clinical Implications

Conclusions

Our study showed a 34% rate of discordance between FS and final diagnosis. Given that 5 cases (7%) were of GI origin, intraoperative assessment of the appendix should be performed in all mucinous ovarian tumors.

Highlights

► We examined 73 consecutive cases of mucinous ovarian tumors that had frozen section (FS) at the time of surgery.
► The rate of discordance between FS and final diagnosis was 34%.
► Consideration of appendiceal tumors is important as 7% of all cancers were found to be gastrointestinal in origin.

abstract: Indication for oophorectomy during cytoreduction for intraperitoneal metastatic spread of colorectal or appendiceal origin

BACKGROUND: The incidence of ovarian metastases at the time of peritoneal carcinomatosis, and the influence of such metastases on survival after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), are unknown.
CONCLUSION: When peritoneal carcinomatosis of colorectal or appendiceal origin is confirmed, at least 52 per cent of ovaries will have synchronous metastases. Disease-free survival after a HIPEC procedure for PMCA or DPAM is significantly lower in women with ovarian metastases. Oophorectomy during CRS for peritoneal carcinomatosis should be strongly considered.

Appendiceal mucinous neoplasms: controversial issues - pathology

Abstract:

"...reviewed is the largely resolved controversy about whether ovarian mucinous tumors in this setting are separate primaries or are metastases from the appendiceal tumor."