Familial non-medullary thyroid carcinoma: pathology review in 27 affected cases from 13 French families

BACKGROUND AND OBJECTIVES When familial nonmedullary thyroid cancer (FNMTC) develops with no obvious associated pathogenetic factor, an inherited pred isposition may underlie the process, The present study was conducted becaus e detailed pathological findings are lacking in most series of FNMTC, PATIENTS AND METHODS Thirteen families comprising 27 cases of FNMTC were in cluded (1.8% of differentiated thyroid carcinoma). The family relationship (20 F, 7 M; age 46 +/- 16 years; mean +/- SD) was 'siblings' in eight famil ies, 'parent and child' in four and 'aunt and niece' in one, Careful pathol ogical review of the thyroid tumours (papillary/follicular: 25/2, size: 16 +/- 11 mm) was performed. RESULTS initial staging according to extension was as follows: grade I (n = 16), II (n = 2), 111 (n = 6), IV (n = 3), Fourteen tumours were papillary microcarcinomas (size: 8 +/- 2 mm), No tumour phenotype that may be conside red specific for FNMTC was found when considering either age, pathological findings or tumour aggressiveness. Although rare events were found in both relatives of some families suggesting a putative 'familial' phenotype of FN MTC, this may be fortuitous, CONCLUSION Micro familial non-medullary thyroid cancers are more common tha n previously reported and further studies are required to be able to distin guish this subgroup from sporadic papillary microcarcinomas. The careful pa thological review of the familial non-medullary thyroid cancer in this stud y does not seem to point to a distinct subgroup of familial differentiated thyroid carcinoma although the data are intriguing. Genetic studies are now required to investigate this issue.