Schilddrüsenmetastasen eines Nierenzellkarzinoms - drei Fallvorstellungen und Übersicht der Literatur

Prevalencia de tumores metastásicos en la glándula tiroides. Revisión sistemática y metanálisis

Introducción y objetivo: Los tumores metastásicos en la glándula tiroides complican el diagnóstico, el tratamiento y el pronóstico del paciente. El objetivo es conocer la prevalencia de las metástasis en la glándula tiroides referida en la literatura médica y los tumores primarios que con más frecuencia metastatizan en la glándula tiroides. Método: Se realizó una revisión bibliográfica sistemática en las bases de datos de PubMed, La Biblioteca Cochrane y Scopus. Los artículos seleccionados se dividieron en dos grupos, series clínicas de pacientes en los que se hallaron metástasis en tiroides (grupo A) y series de hallazgos de metástasis en tiroides en autopsias (grupo B). Se realizó metanálisis de prevalencia para cada grupo de artículos siguiendo el modelo de efectos aleatorios. Resultados: La prevalencia en cada grupo con su índice de confianza al 95% fue 0.00479 (0.002-0.007) para el grupo A y 0.0362 (0.014-0.059) para el grupo B. La prevalencia de metástasis halladas en autopsias fue 7,58 veces mayor que en los estudios clínicos. En el grupo A la edad media fue 60.82 y en el grupo B 57.20. En ambos grupos las metástasis halladas en tiroides fueron más frecuentes en el sexo femenino. La localización del tumor primario fue diferente en ambos grupos, en el grupo A fue el cáncer de riñón y en el grupo B el cáncer de mama. La variabilidad de la prevalencia de metástasis en tiroides en los diferentes artículos de ambos grupos hace que este estudio tuviese una alta heterogeneidad (índice I2 y Q). Los funnel plot de ambos grupos indicaron alto sesgo de publicación. Discusión: La diferente prevalencia entre series clínicas y autopsias puede implicar que la detección de metástasis en tiroides en la clínica está infradiagnosticada. La razón de esto podría ser que las metástasis intratiroideas se presentan de forma asintomática siendo diagnosticadas como hallazgo casual en autopsias. En otras ocasiones se presentan como un nódulo tiroideo años después del tumor primario, lo que condiciona el diagnóstico. Conclusiones: La prevalencia de metástasis en tiroides es superior en las series de autopsias que en series clínicas (hasta 6.67 veces más frecuente en nuestro estudio). Las metástasis intratiroideas probablemente están infradiagnosticadas por cursar sin clínica siendo diagnosticadas como hallazgo casual en autopsias. Los tumores primarios más frecuentes fueron el riñón (series clínicas) y la mama (series de autopsias).

Survival after renal cell carcinoma metastasis to the thyroid: single center experience and systematic review of the literature

BACKGROUND

Renal cell carcinoma can metastasize to uncommon sites, for example, the thyroid gland where metastases are rarely found. To determine the patient survival and the time between cancer diagnosis and thyroid metastasis, we analyzed a large patient cohort from our hospital records and performed a systematic review.

PATIENTS AND METHODS

Patients diagnosed between 1978 and 2007 with thyroid metastases from renal cell carcinoma were retrospectively identified from the hospital database. A systematic literature search was performed for publications describing at least three cases of thyroid metastasis from renal cell carcinoma. Case data from the identified studies were collected and used to determine the survival data.

RESULTS

We identified 34 patients (19 females) from our hospital records with a mean age of 67 years (range, 33-79) when thyroid metastasis was diagnosed. Median time to primary metastasis after resection of renal cell carcinoma was 6.5 years (range, 0-25) with a single case of synchronous metastasis. Median survival after primary metastasis was 4.7 years (95% confidence interval [CI]: 1.8-7.6). The systematic review included 32 studies with 285 patients. Case data could be extracted for 202 patients. Median time to thyroid metastasis (without synchronous cases) was 8.8 years (95% CI: 7.5-10.1). Median actuarial survival after thyroid metastasis was 3.4 years (95% CI: 2.2-4.6). Total thyroidectomy was not associated with a better survival compared to partial thyroidectomies.

CONCLUSIONS

Time to thyroid metastasis of renal cell carcinoma can be very long, and survival after thyroidectomy is favorable compared to metastasis to other sites.

[The metastases to the head and neck region from distant primary localization]

INTRODUCTION

Distant metastases to the head and neck region, with primary tumor located outside the head and neck, presents often a diagnostic problems, especially when metastases are an exclusive signs and symptoms of the disease. In most of this cases there is no chance for curative therapy, and optimum palliation is the goal of the treatment.

AIM

The description and analysis of clinical and prognostic factors, which could establish the optimum diagnostic formula, and predict the prognosis in distant metastases to the head and neck region.

MATERIAL AND METHODS

The study of 44 cases diagnoses and treated in 2001-2006 in Dept. ORL H&N Surgery. The analysis was based on current observations and case records documentation.

RESULTS/CONCLUSIONS

In the most of cases (39/44) the distant metastases to the head and neck regions presented a part of generalized malignant neoplastic disease, but in 14/44 cases that was a first warning symptom. All of this 14/44 cases presented as a metastases to the IV and V lymph nodes region. The most common primary sides were found in the lung. The average survival within the analyzed group was only 7,2 months.

Thyroid dysfunction and kidney disease

Thyroid hormones (TH) are essential for an adequate growth and development of the kidney. Conversely, the kidney is not only an organ for metabolism and elimination of TH, but also a target organ of some of the iodothyronines' actions. Thyroid dysfunction causes remarkable changes in glomerular and tubular functions and electrolyte and water homeostasis. Hypothyroidism is accompanied by a decrease in glomerular filtration, hyponatremia, and an alteration of the ability for water excretion. Excessive levels of TH generate an increase in glomerular filtration rate and renal plasma flow. Renal disease, in turn, leads to significant changes in thyroid function. The association of different types of glomerulopathies with both hyper- and hypofunction of the thyroid has been reported. Less frequently, tubulointerstitial disease has been associated with functional thyroid disorders. Nephrotic syndrome is accompanied by changes in the concentrations of TH due primarily to loss of protein in the urine. Acute kidney injury and chronic kidney disease are accompanied by notable effects on the hypothalamus-pituitary-thyroid axis. The secretion of pituitary thyrotropin (TSH) is impaired in uremia. Contrary to other non-thyroidal chronic disease, in uraemic patients it is not unusual to observe the sick euthyroid syndrome with low serum triodothyronine (T(3)) without elevation of reverse T(3) (rT(3)). Some authors have reported associations between thyroid cancer and kidney tumors and each of these organs can develop metastases into the other. Finally, data from recent research suggest that TH, especially T(3), can be considered as a marker for survival in patients with kidney disease.