Genetic alterations in a primary medullary thyroid carcinoma and its lymph node metastasis in a patient with 15 years follow-up.
BACKGROUND
Association between DNA alterations and clinical parameters as recurrence, survival or prognosis has been found in a variety of tumors. A clear association between Medullary Thyroid Carcinoma (MTC) and RET oncogene mutation has been accepted. Specifically M918T RET mutation represents the main genetic event in most cases of sporadic MTC (SMTC) and limited chromosomal alterations analyses have been performed.


METHODS
In the present work, a comparative genomic hybridization (CGH) study was performed using DNA from a primary tumor in a M918T RET mutation-positive SMTC patient and from its lymph node metastasis to investigate additional genetic alterations. We studied a patient with 15 years of follow-up and persistence of disease, confirmed by periodical elevated serum calcitonin (CT) levels.


RESULTS
Only 3 chromosomal imbalances were identified in the primary tumor, gain of 18p, and loss of 6p and 16p region, whereas 25 chromosomal imbalances were identified in the metastasis (9 gains and 16 losses).


CONCLUSIONS
The chromosomal changes 6p-, 16p-, 18p + could determine in part the oncogenic phenotype in the primary M918T RET positive tumor and probably related to persistence of high serum CT levels in this patient. The additional chromosomal changes observed could be related to the metastasis phenotype. We suggest that some genes mapped at 6p, 16p and 18p chromosomal regions, could act as genes associated to cancer and could be related to persistent SMTC and good prognosis.
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1720753793691097.
Departamento de Medicina y Nutrición, División de Ciencias de la Salud, Campus León, Universidad de Guanajuato, Guanajuato, Mexico.
Beatriz
B
González-Yebra
Raúl
R
Peralta
Ana Lilia
AL
González
Marco Antonio
MA
Ayala-Garcia
María E Medrano Ortiz
ME
de Zarate
Mauricio
M
Salcedo
D000368:Aged; D018278:Carcinoma, Neuroendocrine; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics*; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis / Q000235:genetics; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology
D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human