Resumen Introducción : Se ha descrito que alteraciones molecu lares de las células foliculares tiroideas en el gen BRAF o en NRAS están asociadas con el proceso de carcinogé nesis. Nuestro objetivo fue conocer la frecuencia muta cional de BRAF y NRAS a partir de muestras de punción aspirativa con aguja fina (PAAF) en nuestra población. Métodos : Se analizó por qPCR el estado mutacional de BRAF (codón 600) y NRAS (codón 61) de 193 mues tras obtenidas por PAAF de nódulos sospechosos y se comparó con los datos de la anatomía patológica de 115 pacientes. Resultados : La mutación BRAF se identificó en 40 muestras (74.1%) de las punciones categorizadas como Bethesda VI (n = 54). En las muestras que se correspon dieron con carcinoma papilar de tiroides (CPT) variante clásica por histología (n = 47), el 70% presentó la muta ción, mientras que en los otros subtipos la prevalencia fue más baja (p = 0.013). En muestras de lesión folicular (n = 36), el 50% de los carcinomas foliculares resultaron positivos para NRAS pero solo el 6.7% de los adenomas presentaron esta variación. La presencia de mutación BRAF y CPT se asociaron con metástasis en los gan glios linfáticos (p = 0.014) y mayor riesgo relativo de recurrencia según el Consenso Argentino Intersocietario (RR = 6.77, p = 0.022). No hubo diferencias significativas entre la mutación de BRAF y otras características de agresividad en CPT. Conclusión : La mutación de BRAF y NRAS se observa en un número significativo de CPT y carcinoma folicular, respectivamente, en nuestra población. La mutación BRAF se correlaciona significativamente con metástasis en los ganglios linfáticos.

Abstract Introduction : Molecular alterations in follicular cells in the BRAF or NRAS genes have been reported to be associated with the process of carcinogenesis. Our aim was to determine the mutational frequency of BRAF and NRAS in fine-needle aspiration (FNA) specimens in our population. Methods : The mutational status of BRAF (codon 600) and NRAS (codon 61) was analysed by qPCR in 193 FNA specimens from suspicious nodules and compared with pathological data of 115 patients. Results : BRAF mutation was identified in 40 samples (74.1%) of FNAs classified as Bethesda VI (n = 54). In samples histologically diagnosed as classic papillary thyroid carcinoma (cPTC, n = 47), mutation was observed in 70% of cases, while in other subtypes the prevalence was lower (p = 0.013). In FNA specimens of follicular lesions (n = 36), positivity for NRAS was found in 50% of the follicular carcinomas (FTCs), but only in 6.7% of adenomas. Finally, there was a significant correlation between BRAF and PTC with lymph-node metastasis (p = 0.014) and increased relative risk of recurrence based on the Argentine Intersociety Consensus (RR = 6.77, p = 0.022). No significant differences were found between BRAF mutation and other features of aggressiveness in PTC. Conclusion : BRAF and NRAS mutations are observed in a significant number of PTCs and FTCs, in our popu lation. There is a significant correlation between BRAF mutation and lymph-node metastasis.

SUMMARY Paraneoplastic syndromes are a heterogeneous group of malignant diseases caused by events which involve endocrine, immune and metabolic aspects and whose symptoms vary according to the substance produced and the primary tumor. Hypercalcemia is a frequent complication in cancer patients. Prognosis of cancer patients with hypercalcemia is usually poor. A factor called parathyroid hormone related peptide, whose actions are similar to those of the parathyroid hormone, is thought to be the most common cause of malignancy associated hypercalcemia. Non-islet hypoglycemic cell tumor consists of a rare syndrome characterized by the presence of a solid tumor and severe fasting hypoglycemia determined by an insulin-independent pathway. We report a case of a 59-year-old-man with a renal tumor and a T-cell rich large B cell lymphoma who was hospitalized due to severe hypercalcemia and hypoglycemia. The laboratory examination reported hypercalcemia with inhibited PTH and hypoglycemia with inhibited insulin secretion, arriving to the conclusion of tumoral peptide production. He received denosumab and corticoid therapy. The patient died one month later despite initial improvement after medical treatment. While a single paraneoplastic manifestation may be expected in most tumors, the coexistence of two or more of them is rare, except in hepatocellular carcinomas, and it has not yet been described in renal tumors.

We report the case of a 75-year-old man who was admitted to the hospital with symptoms of severe hypoglycemia. He had a history of solitary fibrous tumor diagnosed by Pathology after its complete surgical resection eight years before. The laboratory examination reported hypoglycemia with inhibited Insulin secretion. A computed tomography of the thorax revealed a large solid heterogeneous mass in the left hemithorax. Solitary fibrous tumor is a rare neoplasm. The association of solitary fibrous tumor and paraneoplastic hypoglycemia is known as Doege-Potter syndrome and occurs in less than 5% of all solitary fibrous tumors.