Resumen Los tumores pardos son raros y, por lo general, afectan huesos largos, pelvis y costillas. Pueden no estar incluidos en el diagnóstico diferencial inicial como manifestación de enfermedad esquelética, es pecialmente cuando se presentan en localizaciones atípicas. Comunicamos dos casos de tumores pardos orales como presentación inicial de hiperparatiroidismo primario. En el primer caso, una mujer de 44 años presentó una lesión dolorosa y sésil de 4 × 3 cm sobre el cuerpo central de la mandíbula que aumentó de tamaño progresivamente en 4 meses. El segundo caso corresponde a una mujer de 23 años que acudió por presentar una masa dolorosa y ul cerada de 2 cm en maxilar izquierdo de 3 meses de evolución, episodios de hemorragia gingival y difi cultad para respirar. Todos fueron tumores solitarios sin evidencia de linfadenopatía cervical palpable. La biopsia incisional de los tumores orales resultó en células gigantes, y las pruebas de laboratorio confirmaron el hiperparatiroidismo primario. Tras la paratiroidectomía, la histología confirmó adenoma en ambos casos. Los tumores pardos representan la etapa terminal de los procesos de remodelación ósea en el hiperparatiroidismo primario. Aunque este tipo de presentación clínica casi ha desaparecido en las últimas décadas, los tumores pardos deben ser considerados en el diagnóstico diferencial de las masas óseas orales.

Abstract Brown tumors represent the terminal stage of bone remodeling processes in primary hyperparathyroidism. Currently they are rare, and typically affect long bones, pelvis and ribs. Brown tumors may be not included in the initial differential diagnosis of bone disease, espe cially when they are present in atypical localizations. We reported two cases of oral brown tumors as the initial presentation of primary hyperparathyroidism. In the first case, a 44-year-old woman presented a painful and sessile lesion of 4x3 cm over the central body of the mandible which progressively increased in 4-month. The second case involved a 23-year-old woman who was referred with a 3-month history of a painful and ulcerated mass of 2 cm arising from left maxilla, episodes of gingival hemorrhage and difficulty of breathing. Both cases were solitary tumors with no evidence of palpable cervical lymphadenopathy. Incisional biopsy of oral tumors resul ted in giant cell and primary hyperparathyroidism was confirmed by laboratory tests. After parathyroidectomy, histology confirmed adenoma in both cases. Although this type of clinical presentation has almost disappeared in the recent decades, brown tumors should be consi dered in the differential diagnosis of bone oral masses.

Medullary thyroid carcinoma (MTC) may rarely present with paraneoplastic syndromes. Among the most frequent ones are the appearance of diarrhea and ectopic Cushing syndrome (ECS). The ECS in the context of MTC is usually present in patients with distant metastatic disease. The use of drugs such as ketoconazole, metyrapone, somatostatin analogs and etomidate have been ineffective alternatives to control hypercortisolism in these patients. Bilateral adrenalectomy is often required to manage this situation. Recently, the use of tyrosine kinase inhibitors has been shown to be a useful tool to achieve eucortisolism in patients with metastatic MTC and ECS. We present a patient with sporadic advanced persistent and progressive MTC with lymph node and liver metastases, which after 16 years of follow-up developed an ECS. After one month of 300 mg/day vandetanib treatment, a biochemical and clinical response of the ECS was achieved but it did not result in significant reduction of tumor burden. However the patient reached criteria for stable disease according to response evaluation criteria in solid tumors (RECIST 1.1) after 8 months of follow-up.

Insulinoma is the most frequent pancreatic islet cell tumor. Clinical manifestations include adrenergic and neuroglycopenic symptoms. Diagnosis is established through demonstration of inappropriately elevated insulin serum concentrations in the presence of hypoglycemia. The aim of this study is to show our experience in the management of insulinoma. Since 1988, 23 women (48 ± 18 years) and 14 men (45 ± 19 years) were studied. Seventy three percent of them suffered mainly from neuroglucopenic symptoms while 27% referred adrenergic signs. Mean duration of symptoms before diagnosis was 2.7 ± 2 years. Mean fasting serum glucose was 32.4 ± 8.7 mg/dl, insulin 38.2 ± 39.7 µU/ml (RIA, n= 11) or 23.8 ± 18.1 µU/ml (chemoluminescence, n=26) and C-peptide 1.15 ± 1.60 nmol/l (n=14). Twenty one patients developed clinical and/or biochemical hypoglycaemia within 9.0 ± 5.2 hours of supervised fast. Preoperative localization was performed in 73% by imaging techniques, arterial calcium stimulation and/or intraoperative ultrasonography and palpation by the surgeon. Thirty six patients were operated on by conventional surgery in 25, or laparoscopic approach in 11 cases. In 22 patients, a solitary tumor was excised (61.1%). Six cases presented multiple insulinomas. Five patients had malignant insulinomas. In one case, a pattern of nesidioblastosis was found and 2 patients presented unspecific findings. In 3 patients another tumour (glucagonoma) was found (1 of them with MEN 1). One patient was treated with verapamil with good clinical response. Mean postoperative follow up was 60.4 ± 59.9 months.

El insulinoma es el tumor neuroendocrino pancreático más frecuente. Se manifiesta por signos adrenérgicos y de neuroglucopenia. Su diagnóstico se confirma documentando la existencia de hipoglucemia junto a una inapropiada secreción de insulina. Desde 1988 fueron estudiados 23 mujeres (48 ± 18 años) y 14 varones (45 ± 19 años) con diagnóstico de insulinoma. La evolución de la enfermedad hasta el diagnóstico fue de 2.8 ± 2.1 años. Veintisiete pacientes (73%) presentaron principalmente síntomas de neuroglucopenia, y el 27% refirió síntomas adrenérgicos. El laboratorio mostró glucemia en ayunas 32.4 ± 8.7 mg/dl, insulina (RIA) 38.2 ± 39.7 µU/ml (n=11), insulina (quimioluminiscencia) 23.8 ± 18.1 µU/ml (n=26), péptido C 1.15 ± 1.6 nmol/l (n=14). El test de ayuno prolongado fue diagnóstico a las 9.0 ± 5.2 horas (n=21). La localización preoperatoria fue posible en el 73% por imágenes, arteriografía con estimulación de calcio y/o ecografía intraoperatoria. Once casos fueron operados por laparoscopia, y el resto por vía convencional. El diagnóstico fue confirmado por histología e inmunohistoquímica. Veintidos pacientes (61.1%) presentaron insulinomas únicos (16 en cuerpo y cola, 6 en la cabeza y proceso uncinado), 6 eran portadores de insulinomas múltiples, 5 de insulinomas malignos, 1 de nesidioblastosis del adulto y en 2 casos los hallazgos fueron incaracterísticos. En 3 pacientes se halló un glucagonoma asociado (1 de ellos con NEM1). Una paciente no fue operada recibiendo tratamiento con verapamilo, con buena respuesta clínica. El seguimiento postquirúrgico fue de 60.4 ± 59.9 meses.