RENAL-CELL CARCINOMA METASTATIC TO THE THYROID-GLAND - A COMPARATIVE MOLECULAR STUDY BETWEEN THE PRIMARY AND THE METASTATIC TUMOR

A case of renal cell carcinoma metastatic to the thyroid gland is pres ented. The thyroid tumor showed typical features: clear cells arranged in nests with a prominent sinusoidal vascular pattern. The histologic appearance was identical to the renal tumor removed 6 yr before. A co mparative molecular study between the primary and the metastatic tumor showed a common profile with a loss of heterozygosity at identical lo ci on chromosome 3, which provided further support to the metastatic n ature of the thyroid tumor. However, the frequent existence of allele losses on chromosome 3p in both renal cell carcinomas and primary thyr oid follicular carcinomas rest some force from such a molecular approa ch to the differential diagnosis of thyroid tumors that contain a pred ominant population of clear cells.