Cateterismo de senos petrosos en el diagnóstico etiológico de síndrome de Cushing: primera experiencia en Uruguay / Petrosal sinus sampling for etiological diagnosis of Cushing's syndrome: first experience in Uruguay / Cateterismo dos seios petrosos no diagnóstico etiológico da síndrome de Cushing: primeira experiência no Uruguai

Resumen: Identificar la causa de un síndrome de Cushing dependiente de adrenocorticotropina (ACTH) es esencial para realizar un tratamiento correcto. La hipersecreción de ACTH es debida en su mayoría a un tumor hipofisario (enfermedad de Cushing) o, en un 10%-20%, a tumores con producción ectópica de esta hormona. Los test no invasivos tienen baja sensibilidad y especificidad para diferenciar estas dos etiologías. El patrón oro lo constituye el cateterismo bilateral de los senos petrosos inferiores (CSP). Mediante el CSP se demuestra la hipersecreción de ACTH a nivel hipofisario al documentar un gradiente de ACTH central a periférico en el drenaje del tumor. Se recomienda realizarlo en todo síndrome de Cushing ACTH dependiente, aunque suele reservarse para pacientes con diagnóstico de hipercortisolismo y hallazgos negativos o equívocos en la resonancia nuclear magnética (RNM) de la región selar. Presentamos el primer caso en Uruguay en que se utilizó el CSP como método diagnóstico, una mujer de 55 años que presentó un hipercortisolismo ACTH-dependiente con una imagen adenohipofisaria <6 mm. El gradiente petroso-periférico confirmó el diagnóstico de enfermedad de Cushing y no hubo complicaciones durante el procedimiento. Posteriormente se realizó la resección del adenoma mediante cirugía transesfenoidal, con buena evolución y confirmación inmunohistoquímica del tumor.

Summary: Identifying the cause of adrenocorticotropin (ACTH)-dependent Cushing's syndrome is key to define the appropriate treatment. Hypersecretion of the adrenocorticotropic hormone (ACTH) is mainly caused by a pituitary tumor (Cushing's syndrome) or, in 10% to 20% of cases, by tumors with ectopic production of this hormone. Differentiation between these two etiologies may not be easy due to the low sensitivity and specificity of non- invasive tests. Bilateral sampling of the lower petrosal sinus is the gold standard to differentiate between a pituitary and an ectopic origin, showing the pituitary ACHT hypersecretion and recording the central-to-peripheral ACTH gradient in the tumor's drainage. Despite it being highly recommended for all cases of ACTH-dependent Cushing's syndrome, it is reserved for patients with a diagnosis of hypercortisolism and negative or misleading findings in the MRI of the sellar region. The study presents the first case of petrosal sinus sampling for diagnostic purposes in Uruguay, in a 55-year-old woman with ACHT-dependent hypercortisolism showing an adenohypophysis image < 6 mm. The petrosal-peripheral gradient confirmed the diagnosis of Cushing's syndrome and no complications arose during the procedure. Afterwards a transsphenoidal surgery was performed for resection of the adenoma. Evolution was good and immunochemistry confirmed the tumor's etiology.

Resumo: Identificar a causa da síndrome de Cushing dependente de adrenocorticotropina (ACTH) é essencial para o tratamento adequado. A hipersecreção de ACTH se deve principalmente a um tumor hipofisário (doença de Cushing) ou, em 10%-20%, a tumores com produção ectópica desse hormônio. Os testes não invasivos apresentam baixa sensibilidade e especificidade para diferenciar essas duas etiologias. O padrão ouro é o cateterismo bilateral dos seios petrosos inferiores (CEP). O CSP demonstra hipersecreção de ACTH no nível da hipófise, documentando um gradiente de ACTH central a periférico na drenagem do tumor. É recomendado nos casos de síndrome de Cushing dependente de ACTH, embora seja geralmente reservado para pacientes com diagnóstico de hipercortisolismo e achados negativos ou duvidosos na ressonância magnética (RNM) da região selar. Apresentamos o primeiro caso no Uruguai em que o CSP foi usado como método diagnóstico, uma mulher de 55 anos que apresentava hipercortisolismo ACTH dependente com imagem da hipófise anterior <6 mm. O gradiente petroso-periférico confirmou o diagnóstico de doença de Cushing e não houve complicações durante o procedimento. A seguir, o adenoma foi ressecado por cirurgia transesfenoidal, com boa evolução e confirmação imunohistoquímica do tumor.

Spontaneous reossification of the sella in transsphenoidal reoperation associated with strontium ranelate.

Spontaneous reossification of the sellar floor after transsphenoidal surgery has been rarely reported. Strontium ranelate, a divalent strontium salt, has been shown to increase bone formation, increasing osteoblast activity. We describe an unusual case of a young patient with Cushing's disease who was treated with strontium ranelate for low bone mass who experienced spontaneous sellar reossification after transsphenoidal surgery. A 21-year-old male presented with Cushing's features. His past medical history included delayed puberty diagnosed at 16 years, treated with testosterone for 3 years without further work-up. He was diagnosed with Cushing's disease initially treated with transsphenoidal surgery, which was not curative. The patient did not come to follow-up visits for more than 1 year. He was prescribed strontium ranelate 2 g orally once daily for low bone mass by an outside endocrinologist, which he received for more than 1 year. Two years after first surgery he was reevaluated and persisted with active Cushing's disease. Magnetic resonance image revealed a left 4 mm hypointense mass, with sphenoid sinus occupation by a hyperintense material. At repeated transsphenoidal surgery, sellar bone had a very hard consistency; surgery was complicated and the patient died. Sellar reossification negatively impacted surgery outcomes in this patient. While this entity is possible after transsphenoidal surgery, it remains unclear whether strontium ranelate could have affected sellar ossification. LEARNING POINTS: Delayed puberty can be a manifestation of Cushing's syndrome. A complete history, physical examination and appropriate work-up should be performed before initiating any treatment.Sellar reossification should always be taken into account when considering repeated transsphenoidal surgery. Detailed preoperative evaluation of bony structures by computed tomography ought to be performed in all cases of reoperation.We speculate if strontium ranelate may have affected bone mineralization at the sellar floor. We strongly recommend that indications for prescribing this drug should be carefully followed.