Characteristics of cribriform morular variant of papillary thyroid carcinoma in post-Chernobyl affected region.

The aim is to study the characteristics of cribriform morular variant of papillary thyroid carcinoma (CMV-PTC) in patients living in the radiation-affected area of Belarus. The clinical and pathological features of 35 patients with CMV-PTC from Belarus were studied and compared with those of conventional papillary thyroid carcinoma diagnosed in the same period. The patients with CMV-PTC were all females and were younger at presentation (mean age = 24) than those with conventional papillary thyroid carcinoma. Familial adenomatous polyposis (FAP) was identified in 20% of the patients with CMV-PTC. The majority of the CMV-PTCs (29/35; 83%) were staged as pT1 and were less advanced than conventional papillary thyroid carcinoma. There was no evidence of lymph node metastases or distant metastases. CMV-PTCs were positive for β-catenin, APC (adenomatous polyposis coli) and p53 proteins. No psammoma bodies were identified on microscopic examination. Over a median follow-up of 9 years, all the patients were alive, and there was no cancer recurrence or mortality related to the thyroid cancer. To conclude, CMV-PTC in patients in the radiation-affected region behaves in an indolent fashion. They had distinctive features that are different from patients with conventional papillary thyroid carcinoma living in the same region.